Short-Barrel Performance — The .45 ACP and Barrel Length

By Bob Campbell published on in Ammunition, Firearms, Range Reports

Cheaper Than Dirt! asked me to work up a report on the differences in .45 ACP ammunition when fired in different barrel lengths. I was already ahead of the game as I have been driven to distraction by the newest GLOCK, the long slide Model 41. I also routinely pack acompact 1911, so the motivation was there and so was the ambition. I always begin an exploration of facts with an open mind and in doing so have learned quite a bit about firearms. I did have several facts on the table, however, that had been qualified by years of testing.

.45 Short Barrel Pistol

The author prefers the 5-inch .45 when possible. The longer sight radius makes precision possible. However, the short guns have their place.

The .45 ACP is a low-pressure cartridge that uses modest charges of fast burning powder. As such, it is not as affected by barrel length as other calibers. The .357 Magnum, as an example, will demonstrate extreme variations in velocity between 2- and 4-inch barrel revolvers. The slow burning powder used in the Magnum often creates a tremendous ball of flame on firing as unburned powder burns outside of the barrel. On the other hand, even when the barrel is as short as 3 inches, the .45 ACP usually produces a full powder burn. Muzzle signature is often a few sparks and little more. Still, there is a proximate loss in velocity in shorter barrels. Whether the loss is significant and whether it impacts wound ballistics was the question. We know that shorter pistols with their short sight radius and shorter grip are inherently more difficult to fire accurately than a long-barrel handgun. That was a different question. Accuracy was not in question, wound ballistics and efficiency are.

All handguns are short-barrel firearms. I think that the conventional sense of short barrel is shorter than standard. A Colt 1911 Government Model uses a 5-inch barrel as standard. The GLOCK 21 is similar. If we are using a Commander .45 we are working with a 4.25-inch barrel. While a rifleman may laugh at handgunners as we agonize over that .75-inch of barrel lost, the fact is in handgun terms the loss of velocity may be significant.

I wished to see just what I was giving up with the short barrel .45 I carry often. Time, hard work and a number of struggles with our protein-fed ex-con criminal class move me to a literary moment. ‘Alas, it is true we have seen better days!’ My back is glad to support a lighter pistol. Today, my threat profile is lower and my mission statement different. My back is not so strong. I still carry a .45, but more often it is a compact. My friend John also carried a short .45, the SIG P250, and had some interest in the equation.

Speer Gold Dot ammunition expansion

The Speer Gold Dot is a particularly good performer in short-barrel handguns. Image courtesy of Speer.

Velocity is a consideration, but so is bullet construction. Bullets are designed for a certain expansion threshold. A bullet designed to open at 1,000 fps isn’t going to open as well at 800 fps. However, if we have a heavy bullet we have greater momentum whether or not we have expansion. As a plus, the spread from the expansion threshold of no expansion to full expansion is much narrower with 230-grain bullets. In my opinion, the heavier bullets are the better choice in short barrel .45s. Conversely, you are able to achieve the greatest advantage with lighter bullets in the long barrel .45s.

When using handloads, I most often use the 230-grain bullet. I most often use faster burning powders such as Bulls Eye and WW 231. It has become a well-known trick in the .45 ACP to use medium, slower burning powders to increase lock time. The pistol stays locked a millisecond longer—at least that is the theory— velocity is kept up and accuracy increased. This is a difficult point to prove or disprove, but my experiments tend to lend this conjecture some validity. However, in the short barrel .45, nothing doing. A slow burning powder simply produced median velocity and excess muzzle flash, with much of the powder burning outside of the barrel—just food for thought for handloaders. Let’s look at the differences in loads when fired in several representative examples of the .45 ACP.

Factory Load Comparison

Cor Bon 160-grain DPX

Handgun Barrel Length Velocity
RIA Compact 3.5 inches 990 fps
SIG P220 4.4 inches 1032 fps
Colt Series 70 5.0 inches 1121 fps

Speer 230-grain Gold Dot

Handgun Barrel Length Velocity
GLOCK M41 5.3 inches 1166 fps
RIA Compact 3.5 inches 770 fps
Colt Commander 4.25 inches 809 fps
Colt 1991A1 5.0 inches 855 fps

185-grain XTP/5.5 Titegroup Handload Comparison

Handgun Barrel Length Velocity
Colt Defender 3.0 inches 867 fps
GLOCK M41 5.3 inches 1011 fps

Next, let’s look at the performance of one of the most popular .45 ACP loads in a short barrel handgun. Speer engineers its 230-grain Gold Dot to give good performance across a range of velocity. After all, the engineers at Speer did not know whether the load would be used in a Government Model or a Defender barrel length. The performance doesn’t seem to leave much to be desired.

Speer Gold Dot Testing

  • Short barrel
  • 770 fps average velocity
Gelatin Test Expansion Penetration
Bare Gelatin .73 inches 14.5 inches
After Penetrating Heavy Cloth .752 inches 14.5 inches
45 Short Barrel with Hornady Ammunition

With proper ammunition selection, a short .45 is both reliable and formidable.

When you get to the bottom line, and considering the differing distances at which you may engage an adversary, the differences in velocity and performance are not that great. The 230-grain .45 offers good penetration and expansion. The shooter must deliver the shot where it will do the most good. A common misconception is that penetration is lost when we fire a load at lower velocity from a short barrel handgun. In the case of the .45 ACP, the opposite is true. As an example, the Hornady 200-grain XTP is recognized as a fine defense load. When fired from a 5-inch barrel, expansion is about .68 and penetration about 16 inches making it an ideal service load. From a short barrel, .45 velocity is lower. Expansion is less with less frontal diameter to push and penetration is usually greater.

An example of a load I have the greatest respect for is the Speer Gold Dot 200-grain +P. This load breaks about 1050 fps from the 5-inch 1911. However, from the 4.4-inch barrel SIG P220, velocity is off nearly 70 fps. The load penetrates about 11 inches and expands to almost 80 caliber from the 5-inch gun. At the lower velocity, penetration is about 12.5 inches and expansion .70—still ideal. The SIG is a full-size pistol with excellent handling qualities so the +P loading is a reasonable choice in this pistol.

The bottom line is this: choose a load that is reliable and burns clean. If recoil is excessive and muzzle signature is anything more than a modest orange glow, consider another choice. Marksmanship is the most important single element of wound ballistics and prior training the single most important factor in surviving a critical incident.

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Share your experiences with .45 ACP and short barrel length in the comment section.

SLRule

Bob Campbell is a former peace officer and published author with over 40 years combined shooting and police and security experience. Bob holds a degree in Criminal Justice. Bob is the author of the books, The Handgun in Personal Defense, Holsters for Combat and Concealed Carry, The 1911 Automatic Pistol, The Gun Digest Book of Personal Protection and Home Defense, The Shooter’s Guide to the 1911, The Hunter and the Hunted, and The Complete Illustrated Manual of Handgun Skills. His latest book is Dealing with the Great Ammo Shortage. He is also a regular contributor to Gun Tests, American Gunsmith, Small Arms Review, Gun Digest, Concealed Carry Magazine, Knife World, Women and Guns, Handloader and other publications. Bob is well-known for his firearm testing.

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Comments (26)

  • Robert HIckey

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    Done s lot of shooting with a 45. Have a iver Johnson 45 with a 4.25 in barrell. Its very acurate at 35 ft. I have found it to be a little more acurate than the 3in. And still good for carry.

    Reply

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