Saturday, September 13, 2014

God's Own Pistol Caliber

If America had a vote for the National Pistol Cartridge, the only contest would be for second place, because .45 ACP is the handgun round Mom would use to hunt wild apple pie from the back of a giant bald eagle. In the list of Great American Institutions, John Browning's thumb-sized thunderbolt falls somewhere between baseball and Mount Rushmore, and it's associated with one type of pistol.

The .45 ACP cartridge and the 5" barrel of the Colt's M1911 Government Model are as evolutionarily intertwined as Thomson's gazelles and cheetahs. But the round is available in every sort of firearm these days, from 2" derringers to 16" carbines; what effect does barrel length have on the velocities of your classic 230gr projectiles?

'Murrica! (and Spain.)
Here assembled we have three .45 ACP pistols with barrel lengths ranging from under four inches to over six. I also brought a box of standard velocity Winchester Ranger 230gr Bonded JHP and a box of Federal Tactical HST 230gr +P. Winchester claims 935fps from a 5" test barrel for the bonded Ranger loading, versus 950 for Federal's +P HST. Let's play with the chronograph!

My personal stable of handguns chambered in .45 ACP has dwindled to a handful of full-size 1911-pattern guns and a 6½" Smith & Wesson Model of 1955 Target, so Bobbi was kind enough to contribute her Star M45 Firestar to the cause of science.

The Firestar is a chunky little thing. With its 3¾" barrel and 6+1 magazine capacity, it's about the physical size of a Colt's Officer's Model, but its all-steel construction and beefy frame with full-length rails that the slide rides inside, a la the CZ75, give it an unloaded weight of 35.6 ounces, only a couple shy of a full-size Government Model.

Consequently, recoil was not unpleasant for such a tiny launch platform. Winchester's Ranger loading averaged 855.9fps from the stubby barrel, while the Federal +P HSTs turned in an 865.1fps average. These velocities were close enough that the fastest of the ten standard pressure loads was actually a couple feet per second faster than the fastest +P. Clearly there's still some powder left to burn.

My Jedi light saber. Built from the ground up on a bare Rock River frame by Gunsmith Bob, it was my last carry 1911. It's sat, unfired, un-lubed, and unloved on a shelf for almost three years and was drier than a popcorn fart. Not gonna lie: I took the bottle of FP-10 out of the range bag in anticipation of having to lube the bejeezus out of the thing to get it running, like a Briggs & Stratton for the first mowing of the season.

I needn't have worried.

From the 5" Kart barrel of the CCA gun, the Winchester Rangers averaged 941.1fps, almost exactly as advertised. The Federal +P load also slightly exceeded expectations, with an average velocity over ten shots of 963.9fps.

As an aside, I had forgotten how good the trigger on this pistol was; measuring a consistent 3.25 lbs on my RCBS fish scale with minimal takeup and no overtravel, it transparently converts the mental desire to fire the pistol into a loud noise and a hole.

If modern custom 1911s can see so far, it is because they are standing on the shoulders of giants, like this Hoag/Auto Shop custom 6½" longslide Colt's Government Model, borrowed from Mike Grasso.

Jim Hoag's longslide conversion is cosmetically seamless and looks factory, completely belying all the welding and refinishing that goes into such a project. It gave the pistol a pleasantly muzzle-heavy feeling, like a heavy-barreled target revolver, as well as providing an extra inch and a half of sight radius. But how much would it affect velocity?

Hardly at all, as it turns out. The standard pressure JHPs averaged 945.5fps, while the +P loads averaged 962.8; essentially the same as the 5" gun. In other words, while going from 3.75" to 5" gains almost 100fps, adding another 1.5" doesn't really gain more speed from these two loads, obviously tuned by their makers to run in a specific type of pistol.

As a footnote, I was well on the way to the range when it occurred to me that the borrowed longslide did not have a magazine in the pistol rug with it, and I'd grabbed my own 1911 without running up to the attic to snare a magazine. I was on the verge of detouring to Premier Arms to grab a couple 47Ds when I remembered there was one magazine in the car, after all. See, that first AFHF class I took with ToddG, back in 2010, I was loading magazines on the morning of the first day and one of the brand new Les Baer mags I'd just pulled out of a baggie felt less than perfectly smooth as I was thumbing rounds into it. Knowing Todd's reputation as a 1911 hater and unwilling to give him a chance to bag on my heater, I tossed the suspect mag in the side pocket of my range bag with the sunscreen and handi-wipes and foam earplugs, where it has remained, lo these four years. As it turned out, I was probably unnecessarily paranoid and yet uncannily prescient at the same time, because who knows when you might find yourself needing a 1911 magazine?