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.)|
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.
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.
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?