Size Doesn't Matter

American Handgunner, Nov, 2000 by Charles E. Petty

WE SET OUT TO PROVE THAT SHORT BARRELED .45s, WITH THEIR LOWER MUZZLE VELOCITIES, SACRIFICE TERMINAL BALLISTICS. WE PROVED OURSELVES WRONG.

We are in something of an arms race to see who can market the smallest, lightest pistol. We've seen that especially in the .45 ACP where Kimber, Colt and some custom 'smiths have vied to see who could bob the shortest barrel. When I reviewed Kimber's Ultra Compact in these pages, I got hate mail from Colt fans who took exception to my awarding the shortest barrel title to Kimber. The complainers didn't bother to measure a barrel. They simply believed what it said in the Colt catalog.

Both companies played a little loose with the numbers. Colt's catalog said that the Defender's barrel was 3". Likewise Kimber for their Ultra Compact. Neither gun's barrel measured exactly 3". Both companies took a little mathematical rounding in their favor.

The Colt barrels I checked-- and there were several-- measured 3.25" compared to 3.16" for Kimber. Kimber reported the actual length of the Colt barrels in their ads, but rounded theirs to the nearest whole number. This allowed them to say that their barrel was 3". The problem comes when all numbers aren't treated the same way. Using Kimber's method, the Colt barrel is 3" too.

Some of those who complained simply were not measuring the barrel length correctly. With the exception of revolvers, the proper measurement of barrel length is the distance from the breech face to the muzzle. With pistols it's a simple thing to use the depth measuring function of a dial or electronic caliper. Just insert the depth gauge into the barrel until it stops on the breech face. That's the barrel length.

So when we say that the Kimber's barrel measures 3.16", we too take advantage of rounding for the caliper actually reads 3.1595". It's easy to go overboard with measuring. Thinking that 0.010" matters in barrel length is ludicrous.

But the logical question to ask is: Do you pay a penalty in bullet performance for a shorter barrel? When I began to work on this project, I would have bet a substantial sum that the answer would be yes.

It didn't quite turn out that way.

Terminal Ballistics

Velocity and expansion go hand-in-hand. You have to have a certain amount of velocity to initiate expansion for any bullet, but too much is just as bad as too little. The current demand for ever higher velocity is grounded in the hoary old myth that you must have 1,000 fps or more for bullets to expand. I cannot believe that anyone still accepts that, but I guess they do.

All hollowpoint bullets depend on a fluid or semi-fluid medium to enter the hollowpoint cavity and push out on the walls to start expansion. Some years ago I had reported on a new bullet and stated that it expanded nicely when fired into ballistic gelatin. I got a truly nasty letter from a reader who called me a liar. He was outraged because he had shot one of the same bullets into a telephone pole and it didn't expand at all.

It should be obvious that measuring all the possible combinations of barrel length and ammo would take on the aura of a life's work. So some arbitrary choices had to be made. Conversations with ammo makers and my own experience suggest that the 230 gr. hollowpoint is the most popular defense load so the decision was made to test premium ammo from the big four: Federal HydraShok, Remington Golden Saber, Speer Gold Dot and Winchester SXT.

In order to have an even marginally valid test, you have to shoot a number of rounds. The plan devised required shooting five rounds of each load through three different barrel lengths. The test pistols were a Chip McCormick 1911 with a 5" barrel, a Colt Lightweight Commander with a 4.25' barrel and a Kimber Ultra Elite whose barrel actually measures 3.16".

The test medium was to be water. Sure it would be great to do this with ballistic gelatin, but the cost is prohibitive. Water is a tough test medium, so if a bullet doesn't expand in water, it is highly unlikely to expand in gelatin or tissue.

The final decision involved how to measure the results. Penetration is not a particular concern. All this ammo was developed using the FBI criteria of 12" penetration-- which is a gracious plenty-- so even though we can't measure it in this test, we haven't lost much.

Expanded diameter and retained weight are important and easily measured. You just have to decide how to do it. There have been lengthy discussions about diameter measurements and most authorities measure the diameter of the lead core. If a fragment of jacket extends beyond the core, it is not measured on the theory that jacket performance is not as predictable.

For our purposes the largest diameter of the lead core was used. You will notice a few measurements where the diameter is considerably less than expected for a .45. In these, the core did not expand at all-- or very minimally-- but the jacket was shed. In one case the bullet didn't expand and retained the jacket, so it is the typical .451".

In this test the measurement of weight retention proved to be slightly more problematic. As stated, water is a more severe test medium than gelatin, but even so it was somewhat surprising to observe the high percentage of bullets that shed their jackets. In most cases it was possible to reassemble the jacket and core. In only a few cases was there any weight loss and this was due to small pieces breaking off the jacket.