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 longslide Model 41.
I also routinely pack a compact 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.
The .45 ACP Cartridge
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 two and four-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 three 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 five-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.
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 — and 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
|RIA Compact||3.5 inches||990 fps|
|SIG P220||4.4 inches||1,032 fps|
|Colt Series 70||5.0 inches||1,121 fps|
Speer 230-Grain Gold Dot
|GLOCK M41||5.3 inches||1,166 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
|Colt Defender||3.0 inches||867 fps|
|GLOCK M41||5.3 inches||1,011 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
|Bare Gelatin||.73 inches||14.5 inches|
|After Penetrating Heavy Cloth||.752 inches||14.5 inches|
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 five-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 1,050 fps from the five-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 five-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.
.45 ACP & Barrel Length
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.
Share your experiences with .45 ACP and short barrel length in the comment section.