Much discussion goes back and forth when it comes to sensible or minimum calibers for personal defense. It could be a case of “bad guy” vs. you… or “bad boar” vs. your tender flesh. I think it all boils down to a few simple facts. In either case, I want a whole lot more than a 25 ACP, 32, 9mm, or even a 40 caliber. Bigger is better, at least in my mind.
Secondly, if the gun is too big and heavy, then it may just get left behind at home on the very day you may need it to defend your life, or your loved ones' lives. Thirdly, while stopping power is very desirable, if the shooter is afraid of his gun, if it has an atomic blast, muzzle flash or recoil, it may also get left at home.
Several years ago, I felt very confident carrying a 10 mm as backup on a bison hunt. When it came time to sort things out, needless to say, the bison was not very impressed. After that experience, I must admit that I ,too, was not very impressed. There had to be a much better tool for the job. I’ve run many tests and evaluations of many shorter barreled revolvers in 44, 45, 480, and even 500 calibers with a focus on moderate charges of medium or faster burning powders to achieve respectable, but not excessive, power levels.
Back in my mind though, there was always a lingering doubt, not about the cartridges or loads, but about the still fairly heavy guns. Does such a carry gun exist that can give the shooter confidence should he enter a critical situation with man or beast? With a new creation from Guncrafter Industries, I sincerely now believe the best of all worlds has been captured in an exciting .500 caliber drop-in conversion unit for the model 20/21 Glock pistols.
Chapter 1: Sensible and Shootable
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I’ve shot many big bore handguns which were so loud, produced horrific muzzle blast and flash, or recoiled so much that I eagerly looked for something else to do. Traits like
this don’t encourage frequent practice to obtain proficiency or confidence in a gun. Being too big or too heavy also may lead to one not carrying the weapon on a regular or as-needed basis, so what good will it be if it's not on your person?
When I took the .50 G.I. converted Glock out to the local police...
range for a SWAT member to shoot, I focused on how the gun and shooter reacted when firing. Muzzle climb with 185, 275, or 300 grain loads resulted in minimal rise at the shot; and there was an obvious absence of muzzle flash and blast. In his own words, the officer said,
“This .50 is totally controllable, even for double taps!” He also kept smiling as I handed him loaded magazines again and again. The Guncrafter Industries conversion unit scores big points in the shootability factor.
Thousands of shooters around the world carry 10mm or 45 ACP Glocks on a daily basis. Holsters and accessories are readily available. The slide on the .50 G.I. is slightly heavier (2.75 ounces) than the standard slides to achieve proper recoil velocities. While some may be able to detect this very slight increase, when fully loaded with 9 + 1 rounds of .50 G.I., I doubt there’s much total difference in feel to a 10mm holding 15 + 1, or a 45 with 13 +1. Bottom line- if you tote around a full size Glock 20 or 21, you really won’t notice a difference should you step up to the .50 G.I. So for me, the conversion unit is both shootable and a sensible carry option for those in search of the ultimate in controllable, portable stopping power.
Chapter 2: Change Your Caliber
If you’ve ever taken the slide off a Glock… that’s the only and exact procedure to install the .50 G.I. conversion. It takes less than a minute to remove the old slide and install the .50 G.I. assembly onto your gun. The unit includes a complete forged stainless slide with sights, a stainless barrel, a 22 lb flat wire captured recoil spring and guide rod, and one 9 shot extended magazine- made for the .50 G.I. from the ground up.
The feed lips are especially designed for the rebated rim of the G.I. cartridge having the same diameter as the classic .45 ACP. The lips guarantee an almost straight-line feed into the chamber and are part of the reason the conversion works so well- it’s a patented feature. Also important is the extra-power 17-7 stainless magazine spring, and the way it stacks during compression. No need to refinance your home, sell off...
one of your cars, motorcycles. or boats, the Guncrafter Industries conversion unit sells in the US for about what the parent Glock pistol costs.
Chapter 3: Cartridge and Handloading
The .50 G.I. cartridge was designed as a rebated case to have the same rim and extractor groove angle as the .45 ACP to ensure reliable feeding in 1911 style guns. Guncrafter Industries first began with their 1911 style Model 1, and then came the tactical Model 2, both in .50 G.I. Always in the back of their mind, though, was the desire to offer a conversion unit for the readily available and popular large caliber Glocks. The brass is made by Starline for Guncrafter, is of extremely strong construction, and is reasonably priced.
Also offered by the company and made by Rainier Bullets are the two projectiles currently offered for sale to reloaders and also used in factory loads- a 275-grain plated hollow point and 300-grain TMJ. In my test gun, the 275-grain round produces 909 fps for 505 ft. lbs.; the 300 does 738 fps and 363 ft. lbs.- both are comfortable to shoot and can be handled by anyone who can manage a .45 ACP. While Alex Zimmerman, owner of Guncrafter Industries and designer of the .50 G.I. concept, believes in the heavy, big bullet concept, he did not leave the velocity clan in the dark.
He also offers a 185-grain copper hollow point (CHP) at a claimed 1,200 fps, but I saw 1,279 fps, good for over 670 ft. lbs., and expansion to over 1-inch with 100% weight retention. In ballistic gelatin testing, the expanded four-petaled projectile penetrated to 9.5” and would still open up after first passing through layers of denim. Also offered is a heavier 230-grain CHP at 1,000 fps. and 510 ft. lbs. Testing revealed a penetration increase of 10.5 ~ 11”, again in ballistic gelatin with similar expansion and 100% weight retention.
For handloading, I assembled some readily available .500 diameter bullets including Guncrafter’s 275 and 300 grain truncated flat points (the lighter being a...
hollow point), 300 grain Speer Gold Dot hollow points and TMJs, as well as their 325-grain Uni-Cor hollow point. I would’ve liked to include the Hornady 300 XTPs, but none were available, so I added their 350-grain XTP meant for the 500 S&W- an altogether different horse. As the case is of modest capacity for its bore size, medium burning rate powders work best in the G.I.. QuickLOAD was used to determine starting and maximum loads, with 21,000 psi as the ceiling- the same as .45 ACP +P loads.
After developing around three dozen top loads for the .50, I conversed with Alex for his recommendations. The .50 G.I. was not designed to be a full-blown magnum but a serious, controllable big bore, unlike anything on the market. Strength of the case is not an issue, but in the lighter weight 1911s and the polymer framed Glock, slide recoil velocity and forces need to stay within original design parameters. Therefore, he suggested to me some recommended velocity maximums for the various bullet weights.
They are as follows: 275-grain: 930 fps., 300: 860 fps, 325: 800 fps., and for the massive 350-grain, 750 fps. At these speeds the .50 G.I. Glock conversion delivers respectively, 528 ft. lbs., 549, 461, and 437 ft. lbs. from the 4.6” stainless barrel. Again note that the 185 CHP produces just over 670 ft. lbs., while the 230 CHP factory load delivers 510.
So I started low and then tested maximums based on a pressure ceiling of 21,000 psi. With Alex’s targeted velocity recommendations, I then worked back down with the powder charges required to hit the desired maximum velocities for each bullet weight. Do note that some of my top loads were only about 100 fps. faster than some of the targeted velocities for each bullet weight. When you’re barking 275 to 350-grain bullets out of a Glock at up close and personal distances, a slightly faster load will only reduce your recovery and controllability- the intended target will not notice a slight reduction in velocity with the developed and recommended loads.
Suitable powders for the .50 with the listed bullets included: Alliant Bullseye, Herco, Unique and Blue Dot; Accurate #7, #9 and 4100; Hodgdon HS-6 and Universal. Also shown are...
recommended loads from Guncrafter Industries, which additionally use Hodgdon’s Titegroup and Power Pistol, and Vihtavuori N330. CCI standard large pistol primers were used exclusively. Time did not permit me to test these loads in my supplied pistol; I do look forward to trying these moderate powered rounds at a later date.
A Lee carbide, four die set was used for reloading, coming with two seater/taper crimp dies, so you can seat and then crimp in two separate operations on a progressive press. I’d like to suggest one of the seater plugs be provided in a flat style, as the curved one rounds out and distorts the 325-grain Speer hollow point nose. As the case uses the same extractor groove angle of the .45, the taper is carried forward to a greater degree due to the case OD of 0.525”. As such, the Lee carbide sizer die actually sizes the head/body of the case to within a sixteenth of an inch or so of the bottom. This is the first cartridge- handgun or rifle- I’ve ever seen such complete full length sizing occur, further ensuring excellent and flawless feeding.
Overall, I found the lighter loads to be comparable to a +P .45 ACP round and the stouter combinations to be very similar to a full-power 10mm load shooting a 200-grain bullet. None of them would be ranked as “magnum” in terms of recoil and surely not as far as muzzle blast or flash. As the SWAT officer said from the start, the .50 G.I. conversion on a Glock 20/21 pistol is totally controllable, even for multiple fast follow-up shots. In part, that is due to the cartridge only using modest charges of medium burning-rate powders.
Fifty or 100 rounds at a session did not have any detrimental effects whatsoever to my hands or wrists, even when shooting the most powerful rounds such as the awesomely expanding factory 185 CHPs. Most loads easily shot into 1.0 ~ 1.5” at 50 feet, which is fairly good to me, considering the stock trigger. I‘m certain that the gun is capable of even better as evidenced by several groups having 3 or more rounds out of 5, in one ragged hole- perhaps it is the jerk behind the trigger and not the jerk of the trigger? I may be guilty as charged!
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Chapter 4: Quality = Confidence
I must take a moment to attempt to convey to you the overall high level of quality evident in the conversion unit. As the photos clearly show, the fit and finish is superb on the forged stainless slide, both inside and out. Not only does the slide look velvety smooth, it feels just as good to the hand. All of the supporting parts that go into the slide also appear to be made with great care in fit and finish.
Taking the barrel out, which is made of 416R stainless and button rifled with deep grooves for great performance with cast bullets, the quality of machining is very evident. All parts seem robust and well thought out. The top of the slide is machined to Glock specs front and rear, so aftermarket alternate sighting systems can easily be used.
When you install the conversion and then shoot it, the whole system reeks of quality. Now also offered, for a slight up charge, is a slide made of 4140 steel having a black Melonite finish providing an extremely hard and corrosion resistant surface very similar in performance to the original Glock matte Tennifer finish. Guncrafters can also black Melonite coat the stainless slides.
Chapter 5: Summary
Shootable, controllable, and easy to carry. More than adequate stopping power. Confidence inspiring due to functionality, quality of fit and finish, design and execution.
The Guncrafter Industries .50 G.I. conversion unit on a Glock 20 or 21 delivers a very decisive blow for a shooter needing to defend himself against man or beast. I’ve shot more powerful handguns, but they belched, roared, flashed, and recoiled far in excess of the task at hand. They also were far too big and heavy for me to want to carry on a regular basis without having to pay a great price in...
terms of comfort and convenience.
I do believe Guncrafters has really nailed it with their big bore conversion of the .50 G.I. on a Glock 20/21 platform. I like that the package is a totally controllable and shooter friendly system which allows one to confidently send large diameter, heavy bullets downrange, up to 10 rounds, one after another. It’s light enough to carry all day and yet friendly enough for most any shooter already comfortable with +P loads in a .45 or full-power 10mm rounds.
They also have developed perhaps the ultimate self-defense round with their 185-grain copper hollow points, at over 1,200 fps. Take a look at the photo of the 10 recovered bullets. Having fearsome expansion and 100% weight retention, it wouldn’t take many of those to make a bad guy want to be somewhere else, wishing he’d never crossed your path with ill intent.