One of the all-time classic military/police/defense handguns, the 1911 .45 is more popular today than ever. For concealed carry, a growing number of people prefer something small. The miniaturization of the 1911 .45, unfortunately, has not been without its stumbling blocks.
1911 History
OK, don't want to start the whole, 'Is the 45 acp good enough protection from bear' debate again (it's what I have and isn't changing), but I have read that ball ammo would make more sense for this purpose than hollow points or self-defence rounds due to extra penetration, makes sense to me.
In 1911, the U.S. military adopted the eponymous Colt pistol just as John Moses Browning designed it. With its 5-inch barrel/slide configuration, it developed an enviable reputation for reliability until 1950, when Colt introduced the first shortened and lightened version, the Commander. It featured a full-size grip frame and took the standard magazine, but the barrel and slide were 0.75 inches shorter. Reducing the stroke length caused some problems, however. Jeff Cooper, the high priest of the 1911 .45, recommended the Commander for convenient concealed carry but suggested the 5-inch-barreled Government Model for duty use. His contemporary, Ray Chapman, who also made the 1911 .45 his signature gun, commented that he found the 5-inch-barreled version more reliable than the 4.25-inch-barreled models. Colt tweaked the Commander, and by the 1980s it squared away any reliability problems with the 4.25-inch-barreled .45s.
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In 1972, the U.S. Army officially adopted the General Officer’s Pistol, a Government Model 1911 .45 with a radically shortened barrel and butt. Crafted and maintained by master armorers and designed to run with only easy-feeding GI hardball ammunition, these pistols were rarely shot and didn’t seem to cause problems. Soon gunsmiths like Armand Swenson began making similar guns; they got them to work reasonably well, but none were famous for accuracy compared to larger .45s.
Colt introduced its Officer’s ACP, the factory answer to the Swenson Bobcat and the Army’s General Officer’s Pistol, in 1985. It was a success commercially but not mechanically. Its accuracy was mediocre at best; these 3.5-inch-barreled guns jammed often with anything but round-nose, full-metal-jacket (FMJ) ammo and Remington jacketed hollow points (JHPs). And they were known to break.
In 1998, Colt introduced the Concealed Carry Officer’s (CCO) pistol, which is basically a Commander barrel/slide as-sembly atop a short Officer’s ACP frame. I fell in love with it, but the public did not; it was only manufactured for a few years. Since then, a custom Gunsite CCO was built by Colt on special order, Wiley Clapp and others called for the CCO to be reintroduced, and many other makers went with the concept.
Then, in 2000, Colt introduced the Defender. Its barrel is half an inch shorter than the troubled Officer’s, at 3 inches, and it amazes knowledgeable 1911 users by working well! Industry scuttlebutt at the time held that the Defender worked because 1911 genius Bill Laugh-ridge of Cylinder & Slide was retained by Colt to supervise the Defender’s design. His custom-made Adventurer pistol had, years before, become the first reliable 3-inch-barreled 1911 .45, and what he had learned was carried over into the Colt Defender line.
Back in 1999 or so, just before the Defender was introduced, Colt’s Joe Cartabona came up to a Lethal Force Institute class I was teaching in New Hampshire to host a focus group on forthcoming new Colt products. We noticed that the prototype Defenders were all way off in their elevation; the company was putting on front sights of the wrong height. To Colt’s great credit, as soon as the company learned of this it held the production line and put proper front sights on those early Defenders before they were shipped out for sale to customers. That’s a corporate responsibility feather in Colt’s cap, in my book.
Gun Details
With an unloaded weight of 24 ounces, its short 3-inch barrel and a short butt, the Defender makes for a compact package. The beavertail grip has a ridge down the center of its spine to guarantee the grip safety will be depressed even with the thumb riding the manual safety. This is a concern because having the thumb in this position pulls the web of the hand slightly back from the grip safety, and Colt was wise to effectively address it in the design.
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Retaining the short butt of the Officer’s model, maximum concealment is gained with the flush-fitting floorplate of the original Officer’s six-round magazine, or the improved generation from Colt with a McCormick-style follower allowing a seventh cartridge in the magazine, bring-ing the total round count up to eight. As an aside, I am partial to Wilson Combat seven-round magazines for these short-butt 1911 .45s. They hold seven rounds thanks to a very slightly extended bottom pad, which also allows more positive seating during reloads.
These guns will take longer 1911 .45 magazines, but there’s one caveat: If a long mag is rammed into place hard with the pistol in slide-lock, it can overtravel and lock up the pistol. Most of us who regularly carry “short-handle” 1911s either use Officer’s length magazines or the Wilson eight-rounder, which has a stop on it to prevent overtravel. However, that stud will keep those magazines from seating in a full-size 1911, so we have to be careful not to get them mixed up.
The Defender is a Series 80 gun, which means that the internal passive firing-pin safety is retained on this handgun. I think that’s important. 1911s with unsecured firing pins discharging when dropped due to inertia is not an urban myth. I just learned of another recent case of it happening with another brand. The Series 80 system has always been an effective preventative for that.
The Defender has fixed, three-dot Novak Low Mount Carry sights. Today’s models are slightly lower in profile than when the pistol was first introduced.
The early ones had Hogue wraparound rubber grips, which seem incongruous at first on a concealment gun, but are welcomed by many because they help to hold the wee beast against sometimes-snappy .45 recoil. I see the same Hogues are on a new production Defender at my local gun shop. However, Tony Landenwich, who won top shot using a Defender during a recent MAG-40 class, apparently had standard stocks on his gun when he bought it, and put on a Hogue wraparound grip out of preference. You’ll find a wide variety of optional stocks to fit these small 1911s; the dimensions have long since been standardized.
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The finish is decent, with some polish on the slide and a flatter gray color to the aluminum frame. Given that the Defender is designed for concealed carry, appearances matter less than dimension and weight to most buyers.
The trigger pull was extremely con-sistent. On my Lyman trigger pull gauge from Brownells, the readout never varied more than 2 ounces, and the average pull weight was 5.63 pounds. Having created and defined the 1911 pistol, produced them longer than anyone else, and made more of them than any other entity, it should be no surprise that Colt has learned how to make 1911 triggers.
My test gun’s trigger pull character-istics were excellent. There is a very short, light take-up and then a short, smooth movement that is best described as a “roll.” The release comes by surprise—the marksman’s ideal. Obviously, it is assumed that you intended to pull the trigger and it’s not the shot that is the surprise, but the actual fraction of a second in which in occurs, so you don’t anticipate the sear release and jerk the trigger. The configuration of the Defender’s trigger has changed a bit over the years, but not the smooth and consistent pull. It is, in short, an excellent “street trigger” for a 1911.
Range Time
Due to schedule demands, I had to test the Colt Defender .45 on a gray and rainy day, but I was at least able to use the concrete bench and Matrix rest on my own range. Ammo from three different makers, all JHPs, encompassed the three most popular bullet weights in .45 ACP. Two were tailored expressly for stubby barrels like the 3-incher on the Defender.
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The lightest bullet was Remington’s 185-grain Express JHP. This old-school “cup and core” bullet has been updated over the years and is normally quite accurate. It wasn’t the little Colt’s favorite, though. It grouped correct for elevation but a bit left for windage, in a pattern that measured 4.65 inches high but only about 2.25 inches wide. The best three-shot group measured a more promising 2.45 inches. It’s customary today to refer to a 4-inch group at the 25-yard distance we were using as the outer limit for “acceptable service pistol accuracy.” However, this standard is generally and mercifully relaxed for very-short-barrel pistols such as this one.
For the traditional 230-grain .45 ACP loading, I chose Speer’s Short Barrel Gold Dot, engineered by Ernest Durham and his team at Speer expressly for just what its name implies: optimum expansion at the reduced velocity that is always the price of the convenient size of a very-short-barreled .45. Interestingly, this load centered exactly where the sights were for both elevation and windage at 25 yards. The group measured 3.55 inches for all five hits, and the best three clustered into 1.45 inches. Two of the bullet holes even nailed the 2-inch Caldwell Orange Peel aiming dot from 75 feet.
The star of the show was the middleweight bullet. A weight of 200 grains was said to be John Browning’s original specification for the .45 ACP cartridge, and there are more than a few shooters who think it’s the optimum with today’s hollow points. Some time ago, Wilson Combat introduced a line of top-quality ammunition under its own brand, including a 200-grain Hornady XTP JHP, which the company advertises as being “optimized for compacts,” though curiously it lists its nominal velocity (975 fps) as coming from a 5-inch barrel. I’d be expecting 900 fps or less from a barrel 2 inches shorter.
The group this pistol delivered with the Wilson ammunition validated “optimized for compacts” as truth in advertising.
All five shots grouped into 1.65 inches, and the best three clustered into 0.7 inches. If you’re familiar with the accuracy levels of short-barrel 1911 .45s, you know that this is nothing less than amazing precision. This tight little knot of bullet holes was about 2.75 inches below the 2-inch Caldwell aiming dot I was six-o’clocking with a post-in-notch sight picture. The shots were dead-center for windage. I figure if I aimed with the white dots, which sit below the top edges of the sights, a three-dot sight picture would have put the group spot on for elevation, too.
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I’ve seen quite a few Defenders go through my school over the years. I don’t recall any that presented functioning problemsto their shooters unless crappy handloads that would have choked any gun were in play. To assess the reliability of a shooting platform, we can take a hint from the old Ford advertisement and “ask the man who owns one.” So I asked Tony Landenwich, the man who won top shot at the MAG-40 class I mentioned earlier in this article. “I bought this gun new a year or so ago,” he told me, “and it’s been my daily carry gun ever since except for days when my hip is really bothering me and I have to go to a .380. I work at a gun shop with an attached shooting range, so I get to practice frequently, and I would guess I have between 5,000 and 6,000 rounds through my Defender. In all that time I’ve only had one malfunction, a failure to feed. I have some nerve damage from a neck injury, and occasionally it makes my hand go numb. I was in that condition that day, and I believe that I simply limp-wristed the Defender and caused the malfunction myself.”
Famed firearms instructor and pistol champion Marty Hayes runs the Firearms Academy of Seattle; he alternates between 1911 and Glock platforms. Marty has had his Colt Defender for more than 10 years, bought new. He estimates running a couple of thousand rounds through it and does not recall a single malfunction. He regularly teaches with it, and was in fact teaching with it the weekend I spoke with him. “It has always been as accurate as I am,” he says. He generally carries it with 185-grain CorBon or Hornady Critical Defense ammunition. “I like the lighter bullet because of the velocity in the short barrel,” he says. “Last hunting season, I shot a deer with my rifle, and it needed a coup de grace from a spine shot. I dispatched it with a 185-grain Critical Defense bullet to the head. I was happy with the performance of the Critical Defense load. It expanded well, with some corollary fragmentation.”
Hayes isn’t the only one who likes a light, fast bullet in a short-barrel .45 ACP. Back in the day, aware of the distinct drop-off in velocity and resultant bullet performance as barrels get shorter, with less space to burn powder and build pressure, I chronographed 185-grain CorBon +P ammunition out of a standard 5-inch-barreled gun, and then a 3.5- inch-barred .45. Out of the full-size gun, I was getting the factory-stated 1,150-fps velocity of the hot load. Out of the short-barrel gun, it was still traveling at about 1,070 fps. By contrast, a standard-pressure 185-grain load like the Silvertip was spec’d for 1,000 fps out of a 5-inch barrel, and often delivering less. The +P loadings enhance recoil, of course, but it’s nothing a trained and committed shooter can’t handle.
Final Notes
Many firearms instructors and even gunsmiths will tell you to avoid very-short-barrel 1911 pistols because they don’t cycle as reliably as their larger forebears. For the most part, I would agree with that. However, for a good 14 years now, the Colt Defender has proven to be the exception to this rule.
I’m still more likely to carry one of my CCO pistols, which I’ve always preferred to the Defender size, or my CCO-like Nighthawk T3. I get a better sight radius and higher velocity, and while the CCO motif gives me the same concealment at the butt as the Defender, its desirable 4.25-inch barrel/slide hides perfectly in an inside-the-waistband holster for me, so the 3-inch-barreled Defender does not help me in that regard. However, I’m clearly in the minority: The CCO has been out of production for quite some time, and the Defender has remained in the Colt catalog as a steady, customer-satisfying seller since its introduction in 2000.
Uncommonly reliable and surprisingly accurate, the Colt Defender would be at the very top of my list of short-barrel, short-butt 1911 .45 pistols. It carries a manufacturer’s suggested retail price of $1,098. Given the performance I’ve seen from the Colt Defender over the years, I think it’s worth every penny.
For more information on the Defender, visit colt.com or call 800-962-2658.
Colt Defender .45 ACP Specifications:
* Caliber: .45 ACP
* Barrel: 3 inches
* OA Length: 6.75 inches
* Weight: 24 ounces (empty)
* Grips: Rubber
* Sights: Novak Low Mount Carry
* Action: SA
* Finish: Stainless slide, Cerakote frame
* Capacity: 7+1
* MSRP: $1,098
* Barrel: 3 inches
* OA Length: 6.75 inches
* Weight: 24 ounces (empty)
* Grips: Rubber
* Sights: Novak Low Mount Carry
* Action: SA
* Finish: Stainless slide, Cerakote frame
* Capacity: 7+1
* MSRP: $1,098
Colt Defender .45 ACP Performance:
* Remington 185 Express JHP – 4.65
* Speer 230 Short Barrel Gold Dot – 3.55
* Wilson Combat 200 Hornady XTP JHP – 1.65
* Bullet weight measured in grains, and accuracy in inches for best five-shot groups at 25 yards.
* Speer 230 Short Barrel Gold Dot – 3.55
* Wilson Combat 200 Hornady XTP JHP – 1.65
* Bullet weight measured in grains, and accuracy in inches for best five-shot groups at 25 yards.
This article was originally published in COMPLETE BOOK OF HANDGUNS 2014. Subscription is available in print and digital editions below.
.45 ACP | ||||||||||||||||||||||||
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.45 ACP cartridges full metal jacket (left) and hollow-point (right). | ||||||||||||||||||||||||
Type | Pistol | |||||||||||||||||||||||
Place of origin | United States | |||||||||||||||||||||||
Service history | ||||||||||||||||||||||||
Wars | World War I – present | |||||||||||||||||||||||
Production history | ||||||||||||||||||||||||
Designer | John Browning | |||||||||||||||||||||||
Designed | 1904 | |||||||||||||||||||||||
Produced | 1905–present | |||||||||||||||||||||||
Variants | .45 ACP +P, .45 Auto Rim, .45 Super | |||||||||||||||||||||||
Specifications | ||||||||||||||||||||||||
Case type | Rimless, straight | |||||||||||||||||||||||
Bullet diameter | .451 in (11.5 mm) | |||||||||||||||||||||||
Neck diameter | .473 in (12.0 mm) | |||||||||||||||||||||||
Base diameter | .476 in (12.1 mm) | |||||||||||||||||||||||
Rim diameter | .480 in (12.2 mm) | |||||||||||||||||||||||
Rim thickness | .049 in (1.2 mm) | |||||||||||||||||||||||
Case length | .898 in (22.8 mm) | |||||||||||||||||||||||
Overall length | 1.275 (32.4 mm) | |||||||||||||||||||||||
Case capacity | 26.7 gr H2O (1.73 cm3) | |||||||||||||||||||||||
Rifling twist | 1 in 16 in (406 mm) | |||||||||||||||||||||||
Primer type | Large, medium and Small pistol | |||||||||||||||||||||||
Maximum pressure (small arms ammunition pressure testing | 19,000 psi (130 MPa) | |||||||||||||||||||||||
Maximum pressure (small arms ammunition pressure testing | 21,000 psi (140 MPa) | |||||||||||||||||||||||
Ballistic performance | ||||||||||||||||||||||||
|
The .45 ACP (Automatic Colt Pistol), or .45 Auto (11.43×23mm)[1] is a handgun cartridge designed by John Moses Browning in 1905, for use in his prototype Coltsemi-automatic pistol. After successful military trials, it was adopted as the standard chambering for Colt's M1911 pistol, being named .45 ACP.[2]
- 7Load variants
Design and history[edit]
During the late 1890s and early 20th century, the U.S. Cavalry began trials to replace their sidearm arsenal of issued .45 ColtSingle Action Army (SAA) in favor of the more modern and versatile double-action revolver in .45 Colt.
After the example of the Cavalry, the Army in turn had fielded versions of double-action revolvers in .38 Long Colt. It was eventually evaluated that the .38-caliber round was significantly less effective in overall stopping-power than the .45 Colt against determined opponents in cases such as the Morojuramentado warriors, who were encountered in the Moro Rebellion.[3][4][5][6] The then-current issue rifle, the .30-40 Krag, had also failed to stop Moro warriors effectively;[7] the British had similar lack-of-stopping-power issues switching to the .303 British, which resulted in the development of the dum-dum bullet in an attempt to compensate for the round's deficiencies. This experience, and the Thompson–LaGarde Tests of 1904, led the Army and the Cavalry to decide a minimum of .45 caliber was required in a new handgun. Thompson and Major Louis Anatole La Garde of the Medical Corps arranged tests on cadavers and animal remains in the Chicago stockyards, resulting in the finding that .45 was the most effective pistol cartridge. They noted, however, training was critical to make sure a soldier could score a hit in a vulnerable part of the body.
Colt had been working with Browning on a .41 caliber cartridge in 1904, and in 1905, when the Cavalry asked for a .45 caliber equivalent, Colt modified the pistol design to fire an enlarged version of the prototype .41 round. The result from Colt was the Model 1905 and the new .45 ACP cartridge. The original round that passed the testing fired a 200 grain (13 g) bullet at 900 ft/s (275 m/s), but after a number of rounds of revisions between Winchester Repeating Arms, Frankford Arsenal, and Union Metallic Cartridge, it ended up using a 230 grain (14.9 g) bullet fired at a nominal velocity of 850 ft/s (260 m/s). The resulting .45-caliber cartridge, named the .45 ACP, was similar in performance to the .45 Schofield cartridge, and only slightly less powerful (but significantly shorter) than the .45 Colt cartridges the Cavalry was using.
By 1906, bids from six makers were submitted, among them Browning's design, submitted by Colt. Only DWM, Savage, and Colt made the first cut. DWM, which submitted two Parabellum P08s chambered in .45 ACP, withdrew from testing after the first round of tests, for unspecified reasons.[8]
In the second round of evaluations in 1910, the Colt design passed the extensive testing with no failures, while the Savage design suffered 37 stoppages or parts failures.[8] The Colt pistol was adopted as the Model 1911.
The cartridge/pistol combination was quite successful but not satisfactory for U.S. military purposes. Over time, a series of improved designs were offered, culminating in the adoption in 1911 of the 'Cal. .45 Automatic Pistol Ball Cartridge, Model of 1911', a 1.273 in (32.3 mm) long round with a bullet weight of 230 grains (15 g). The very first production, at Frankford Arsenal, was marked 'F A 8 11', for the August 1911 date.
Other US military cartridges include: tracer M26 (red tip), blank M1921 (rolled crimp, red paper wad), M12 and M15 shot shells, and M9 dummy (holes in case).
The cartridge was designed by John Browning for Colt, but the most influential person in selecting the cartridge was Army Ordnance member Gen. John T. Thompson. After the poor performance of the Army's .38 Long Colt pistols evidenced during the Philippine–American War (1899–1902), Thompson insisted on a more capable pistol cartridge.[9]
Cartridge dimensions[edit]
The .45 ACP is manufactured with both large and small pistol primers.
The .45 ACP has 1.62 ml (25 grains H2O) cartridge case capacity.
.45 ACP maximum C.I.P. cartridge dimensions.[10] All sizes in millimeters (mm).
The common riflingtwist rate for this cartridge is 406 mm (1 in 16 in), 6 grooves, Ø lands = 11.23 mm, Ø grooves = 11.43 mm, land width = 3.73 mm and the primer type is large pistol.The cartridge headspaces on the mouth of the case at the L3 datum reference.[11]
According to Commission Internationale Permanente pour l'Epreuve des Armes à Feu Portatives rulings, the .45 ACP cartridge case can handle up to 131.000 MPa (18,999.9 psi) Pmax piezo pressure. In CIP-regulated countries every pistol cartridge combination has to be proofed at 130% of this maximum CIP pressure to certify for sale to consumers. This means that .45 ACP chambered arms in C.I.P. regulated countries are currently (2016) proof tested at 170.30 MPa (24,700 psi) PE piezo pressure.[10]
The SAAMI pressure limit for the .45 ACP is set at 21,000 psi (144.79 MPa) piezo pressure,[12] whilethe SAAMI pressure limit for the .45 ACP +P is set at 23,000 psi (158.58 MPa), piezo pressure.
Performance[edit]
The .45 ACP is an effective combat pistol cartridge that combines accuracy and stopping power for use against human targets. It has relatively low muzzle blast and flash, and it produces a stout, but manageable recoil in handguns, made worse in compact models. The standard issue military .45 ACP round has a 230-grain bullet that travels at approximately 830 feet per second when fired from the government issue M1911A1 pistol and approximately 950 feet per second from the M1A1 Thompson submachine gun. The cartridge also comes in various specialty rounds of varying weights and performance levels.[2]
It operates at a relatively low maximum chamber pressure rating of 21,000 psi (145 MPa) (compared to 35,000 psi/241 MPa for 9mm Parabellum and .40 S&W, 37,500 psi/259 MPa for 10mm Auto, 40,000 psi/276 MPa for .357 SIG), which due to a low bolt thrust helps extend service life of weapons in which it is used. Some makers of pistols chambered in .45 ACP do not certify them to use Plus P ammunition.
In its non-expanding full metal jacket (FMJ) version, the .45 ACP cartridge has a reputation for effectiveness against human targets because its heavy mass has the capacity to penetrate tissue deeply and damage the central nervous system, and its large 11.5mm diameter creates a more substantial permanent wound channel than other calibers, which can lower blood pressure rapidly if critical organs of the circulatory system are hit.
In its expanding hollow point form, it is also particularly effective against human targets. In tests against ballistic gelatin, a 185 grain hollow point traveling at 1,050 feet per second expanded to about .76 inches. This is a significantly large permanent wound cavity for a handgun projectile. For those who follow the energy dump and/or hydrostatic shock theories of wounding ballistics, this is ideal. While slightly decreasing penetration and likewise the chance of hitting a vital organ, a large diameter wound will cause more blood loss. There is also a reduced likelihood of overpenetration, meaning that it is more likely that the projectile will transfer all of its kinetic energy to the intended target, thus more reliably incapacitating them.
Drawbacks for military use include the cartridge's large size, weight, increased material costs in comparison to the smaller, flatter shooting NATO standard 9×19mm Parabellum cartridge, which uses less powder, brass, and lead per round. Standard 9mm NATO ammunition has limited armor penetration capability − a deficiency with .45 ACP whose large, slow bullet does not penetrate armor to any great extent. The low muzzle velocity also makes the bullet drop over long ranges, making hits more difficult; however, it is important to note that the vast majority of self-defense situations involving handguns typically occur at close ranges.
Recent testing of the three major police and military calibers by the Federal Bureau of Investigation found that the .45 ACP was no more effective with regard to terminal ballistics than either 9 x 19mm Parabellum or .40 S&W. After two years of testing, one of the final FBI comments was that services that adopt (or stay with .40 S&W or .45 ACP) did so at the risk of increased recoil and a possible reduction in accuracy as 9 x 19mm with premium quality ammunition had nearly exactly the same performance.[13] A factor rated by the recent FBI testing was accuracy and time to recover. The .45 ACP handguns ranked last, largely due to increased recoil. Additionally, some firearms selected were also less safe.[13]
Because of its large diameter and straight-walled design, the .45 ACP geometry is the highest power-per-pressure production, repeating round in existence. This is because of the higher powers achievable with .45 Super, and +P loads. Because of these inherent low pressures of the standard pressure round, however, compensators and brakes have little effect until +P and Super loads are utilized.[14]
Magazine capacities[edit]
With standard (not extended) single-stack magazines, pistols chambered in .45 ACP usually hold 8 rounds or less (exceptions to this include the 10-round standard 14 round extended capacity .45 ACP from Sig Sauer in their P227 [15] and 13-round Glock 21)[16] and 15 rounds, such as the .45 ACP versions of the FN FNP and FN FNX, though this greatly increases the pistol's bulk and with that lowers concealability.[17] The Heckler and Koch USP .45 standard has a double-stack magazine that holds 12 cartridges.
Adoption[edit]
.45 ACP hollowpoint (Federal HST) with two .22LR cartridges for comparison
Side on view of Sellier & Bellot .45 ACP cartridge with a metric ruler for scale
Several US tactical police units still use the .45 pistol round.[18][19][20] While high capacity firearms are available in .45 ACP, the greater length and diameter of the .45 ACP means that the grip of the pistol must be longer and wider than the grip of a comparable pistol of a smaller caliber; this increase in grip size can make the pistol difficult to use for shooters with smaller hands.
Today, most NATO militaries use sidearms chambered for the 9×19mm Parabellum cartridge, but the effectiveness of the .45 ACP cartridge has ensured its continued popularity with large caliber sport shooters, especially in the United States.[21] In addition, select military and police units around the world still use firearms firing the .45 ACP.[21] In 1985, the .45 ACP M1911A1 pistol was replaced by the Beretta M9 9mm pistol as the main sidearm of the U.S. military, although select Special Operations units continue to use the M1911A1 or other .45 ACP pistols.
Operating speeds[edit]
Because standard pressure .45 ACP rounds fired from handguns and submachine guns are inherently subsonic, it is one of the most powerful pistol calibers available for use in suppressed weapons since subsonic rounds are quieter than supersonic rounds. The latter inevitably produce a highly compressed shock wave, audible as a loud 'crack', a small sonic boom, while they travel through the air. Suppressors reduce the audible 'report' by slowing and channeling the high speed gas generated by the burning/expanding gunpowder before it exits the muzzle resulting in a muffled 'cough'. Suppressors cannot act on a supersonic shock wave continuously generated by a bullet exceeding the 1,087 ft/s (331 m/s) speed of sound at 32 °F (0 °C) ambient cold temperatures, as this shock wave is continuously produced throughout the entire flight path over which the bullet is supersonic, which extends long after it exits the barrel.
The downside to the use of .45 ACP in suppressed weapons is that increasing the diameter of the passage through a suppressor decreases the suppressor's efficiency; thus, while .45 ACP is among the most powerful suppressed pistol rounds, it is also one of the loudest. Most .45 suppressors must be fired 'wet' (with an ablative medium, usually oil or water) to bring sound levels down to 'hearing-safe' (under 140 dB, generally).[22]
Base of Sellier & Bellot .45 ACP cartridge, showing lacquered primer
Several .45 ACP variants: hollow point, full metal jacket, WWII-era military issue birdshot
A target handload with cast 200-grain semiwadcutter bullet
A modern 230-grain jacketed hollow point bullet recovered after hitting flesh
![45acp Hardball Specs 45acp Hardball Specs](/uploads/1/2/5/8/125847041/420651643.jpg)
Load variants[edit]
Rounds are available from 68 grains to 300 grains (4.4 g to 16.5 g) with a common load being the standard military loading of a 230-grain (15 g) FMJ bullet (for comparison, the most common 9mm load is 115 grains (7.5 g), quite literally half the weight). Specialty rounds are available in weights under 100 grains (6.5 g) and over 260 grains (16.8 g); popular rounds among reloaders and target shooters include 185-grain and 230-grain (12 g and 15 g) bullets.[citation needed] Hollow-point rounds intended for maximum effectiveness against live targets are designed to expand upon impact with soft tissue, increasing the size of the permanent cavity left by the bullet as it passes through the target.
Tracer ammunition for the .45 ACP was manufactured by Frankford Arsenal and by Remington Arms. This ammunition was available to the United States Border Patrol as early as 1940 and was used through World War II for emergency signalling by downed United States Navy and Marine Corps air crew. Tracer ammunition was identified by painting the bullet tip red.[23]
Plus P[edit]
Most ammunition manufacturers also market what are termed '+P' (pronounced 'plus P') loadings in pistol ammunition, including the .45 ACP. This means the cartridge is loaded to a higher maximum pressure level than the original SAAMI cartridge standard, generating higher velocity and more muzzle energy. In the case of the .45 ACP, the new standard cartridge pressure is 21,000 psi (140 MPa) and the SAAMI .45 ACP +P standard is 23,000 psi (160 MPa). This is a common practice for updating older cartridges to match the better quality of materials and workmanship in modern firearms.[21]
The terminology is generally given as '.45 ACP +P', and sometimes but not always appears on the headstamp. These cartridges have the same external dimensions as the standard-pressure cartridges and will chamber and fire in all firearms designed for the standard-pressure loadings. The inner dimensions of the +P cartridge are different from the standard-pressure cartridge dimensions and thus allows for higher pressures to be safely achieved in the +P cartridge. If +P loadings are used in firearms not specifically designed for them they may cause damage to the weapon and injuries to the operator.
Others[edit]
Popular derivative versions of the .45 ACP are the .45 Super and .460 Rowland.[21] The Super is dimensionally identical to the .45 ACP; however, the cartridge carries a developer established pressure of 28,500 psi (197 MPa) and requires minor modification of firearms for use. The Rowland operates at a developer established 40,000 psi (280 MPa) SAAMI and may only be used within a select group of firearms significantly modified for this purpose; the Rowland case is 0.057 inches (1.4 mm) longer specifically to prevent it from being chambered in standard .45 ACP firearms. Brass cases for each of these cartridges carry the applicable name within the headstamp. The Super provides approximately 20% greater velocity than the .45 ACP +P; the Rowland approximately 40% greater velocity than the .45 ACP +P.[21]
Synonyms[edit]
- 45 (Colloquial in English, Spanish and Tagalog)
- .45 Rimless Smokeless
- .45 Auto
- .45 Auto. Colt / .45 AC (Winchester Repeating Arms Company)
- .45 M1911 (US Military)
- S.A. .45-inch (Commonwealth Military)
- S.A., Pistol, .45-inch Colt Automatic, Ball (1917) was the British designation used for American-manufactured ammunition. The Royal Navy had purchased a shipment of M1911 pistols in 1917 along with enough ammunition for evaluation, training and service purposes. It was never standardized by the Lists of Changes, but was mentioned in the Vocabulary of Priced Stores. It came in 7-round packets and was manufactured by Winchester.
- S.A., .45-inch, Ball Mk Iz (1940-1945) was the designation used for American-manufactured ammunition and proposed British manufacture of .45 M1911 Ball. Lend-Lease ammunition came in commercial 42-round Winchester or 50-round Western Cartridge Company cartons. US military-issue ammunition came in 20-round cartons, shifting to larger 50-round cartons in early 1942. It was never manufactured in Britain because it was readily available from American forces.
- S.A., .45-inch, Ball Mk IIz (1943) was a variant proposed for the Royal Navy, but never put into production.
- S.A., .45' A. C., Ball (1942-1946) was the Canadian designation for their domestically-manufactured ammunition for use in the European theater. It came in a plain 42-round carton that mimicked the capacity and dimensions of the yellow commercial Winchester ammunition cartons sold to Britain through Lend-Lease.
- S.A., .450-inch, Ball Mk IIz (1943-1956) was used for Australian-manufactured ammunition for use in the Pacific theater. It came in 24-round cartons.
- 11.43×23 mm (Metric)
- 11.25 mm (Norway,[24] Argentina[25])
- 11 mm 4 (France)
- 11 mm (Colloquial in Southeast Asia)[26][27][28]
Related rounds[edit]
- .451 Detonics Magnum[29]
- .45 Peters-Thompson shot cartridge[30]
- .50 GI[31]
See also[edit]
References[edit]
- ^JEFFREY., STRICKLAND, PRESIDENT (2014). HANDBOOK OF HANDGUNS. [S.l.]: LULU COM. p. 151. ISBN978-1300973294. OCLC1020871429.
- ^ abBarnes, Fred C (2014). Cartridges of the World. Iola, WI, USA: Krause Publications. ISBN978-1-4402-4265-6.
- ^DK (October 2, 2006). Weapon: A Visual History of Arms and Armor. DK Publishing. p. 290. ISBN978-0-7566-4219-8.
- ^Green Muse Writers Collective, The (December 2008). Keep Calm Carry on: A Survival Guide. iUniverse. p. 138. ISBN978-1-4401-0249-3.
- ^'Juramentados and the development of the Colt .45 caliber Model 1911 - The Manila Times Online'. www.manilatimes.net. June 29, 2014.
- ^'ANG 'KALIBRE 45' AT ANG PAKIKIBAKA NG MGA MANDIRIGMANG PILIPINO'(PDF). Archived from the original(PDF) on October 9, 2016. Retrieved January 8, 2018.
- ^1911 HistoryArchived July 16, 2006, at the Wayback Machine
- ^ ab'Background Information on the M1911 .45 Caliber Pistol'. www.sightm1911.com.
- ^JEFFREY., STRICKLAND, PRESIDENT (2014). HANDBOOK OF HANDGUNS. [S.l.]: LULU COM. p. 153. ISBN9781300973294. OCLC1020871429.
- ^ ab'C.I.P. TDCC sheet .45 Auto'(PDF).
- ^Wilson, R. K. Textbook of Automatic Pistols, p.229. Plantersville, SC: Small Arms Technical Publishing Company, 1943. ISBN0-935632-89-1
- ^'SAAMI Pressures'. Archived from the original on October 14, 2007. Retrieved November 29, 2007.
- ^ ab'Case Closed: FBI Says 9mm Is The Best Pistol Round'. grandviewoutdoors.com. September 26, 2014. Retrieved February 23, 2017.
“There is little to no noticeable difference in the wound tracks between premium line law Auto enforcement projectiles from 9mm Luger through the .45 Auto.”
- ^McAlpine, Alex. 'Pressure to power of combat cartridges'. BrainLubeOnline.com. Retrieved November 10, 2013.
- ^'Sig Sauer P227 .45 ACP 14RD Extended Magazine'. topgunsupply.com. Retrieved February 23, 2017.
- ^'Top 5 .45s for Home Defense'. gunsamerica.com. January 13, 2015. Retrieved February 23, 2017.
- ^Ayoob, Massad. 'Choose your ammo ... police style'. Backwoods Home Magazine. Archived from the original on February 25, 2007. Retrieved February 21, 2007.
- ^Diez, Octavio. Special Police Task Forces. Lima Publications. p. 40.ISBN978-84-95323-43-9
- ^Hogg, Ian. Jane's Gun Recognition Guide, 2nd Edition. Harper Collins Publishers. p. 113.
- ^Hopkins, Cameron (2000). 'Most Wanted'. American Handgunner. Publishers Development Corporation. Archived from the original on December 9, 2004. Retrieved February 21, 2007.
- ^ abcdeBarnes, Frank C.; Skinner, Stan (2003). Cartridges of the World: 10th Edition, Revised and Expanded. Krause Publications. p. 528. ISBN978-0-87349-605-6.
- ^Truby, J. David(1987)Silencers, Snipers, and Assassins...an Overview of Whispering Death, Paladin Press, Boulder, CO, 216 pp. ISBN0-87364-012-8
- ^Andrews, Dave 45 ACP Tracers on page 20 of February 2002 American Rifleman magazine
- ^Wikipedia, Morphinea at English (April 25, 2007). 'Kongsberg Colt - Norwegian M1914' – via Wikimedia Commons.
- ^MCarranza. 'Español: Evolucion de los marcajes de las pistolas sistema Colt del ejercito Argentino' – via Wikimedia Commons.
- ^Limited, Bangkok Post Public Company. 'Fugitive gunman shoots drug-taking relative'.
- ^Limited, Bangkok Post Public Company. 'Cheap handgun scheme misfires'.
- ^VCCorp.vn. 'Súng ngắn mạ vàng thiết kế riêng cho Tổng thống Mỹ Donald Trump'.
- ^'Short History of the .451 Detonics Magnum'. August 5, 2012.
- ^'THE THOMPSON SUB-MACHINE GUN'. Archived from the original on August 16, 2000. Retrieved November 11, 2014.
- ^'Cartridge Interchangeability'. TINCANBANDIT's Gunsmithing. October 15, 2014.
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External links[edit]
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