.50GI Glock Conversion from Guncrafter Industries
By Jeff W. Zimba

In the April, 2010 (Vol. 13, No. 7) issue of Small Arms Review we introduced you to the .50GI cartridge and the meticulously manufactured 1911 style Model 1 from Guncrafter Industries. The Model 1 as you may recall is a custom built, somewhat expensive platform for the discriminating shooter looking for the ultimate 1911 performance gun. Since the price is a big factor in any gun purchase, and the interest in pistols runs well outside of the time-proven 1911 style designs, Guncrafter Industries has taken the next step to broaden the appeal of their .50GI round in several aspects. It is in this issue we are pleased to test and evaluate their latest offering, the .50GI conversion unit for the extremely popular Glock series pistol, at a price that will have most every big-bore pistol enthusiast adding this to their Christmas list.

Since the Austrian-based Glock pistols first made their debut in the United States in the mid 1980s, they have gone through numerous stages of improvements, size and design changes, caliber offerings and upgrades. Originally a mere curiosity due to its polymer construction, lightweight design and proprietary “safe action trigger,” they were often wrongfully misaligned and demonized by Hollywood and the venomous anti-gun crowd in their never-ending quest to market fear, with facts falling a distant second place in their campaigns. Foolishly branded by politicians as “a plastic handgun, undetectable to airport security” it faced an uphill battle from the beginning but facts and common sense prevailed as it always does. Today, Glock pistols in their many variations are extremely popular and widely used in the competitive, civilian and law enforcement markets in great numbers. Their reputation for reliability and the sheer numbers on the market made the Glock a clear choice for the next evolution of the .50GI cartridge.

The Basics

The new .50GI Glock conversion was designed for use on the Model 20 and Model 21 frames, factory chambered from 10mm and .45 ACP respectively. The .50GI conversion is a true “drop-in” installation and includes the new barrel, slide, springs, op-rod and magazine. Installation is as simple as clearing your original Model 20 or 21, removing the slide and replacing it with the complete Guncrafter Industries .50GI slide. The original magazine is replaced with the new .50GI magazine and you are finished and ready to shoot. The magazine capacity varies from 9+1 or 8+1 depending on whether an extended base is used. The slide is machined from a stainless steel forging and the barrel is stainless steel as well. The magazine is manufactured from the same familiar polymer material as the original.

Like everything else that Guncrafter Industries is involved in, quality is the number one concern, and the fit, finish and function of the .50GI Glock conversion is no exception. The fine lines of the machined slide are paralleled by the clean, clear engraving of all logos and text and the finish is a dark black that matches the frame well.

Heavyweight or Lightweight?

One of the first questions we wanted to address was the weight of the .50GI and all its variables. The general rule of thought is that the “heavier” caliber may translate into an actual increase in overall weight and we wanted to get to the bottom of it right away. Since we received a late generation “SF” Glock 21 frame with the .50GI conversion kit we decided to see how it stacked up against an earlier generation Model 21 frame. The “SF” frame is thinner and feels a little more like the Model 17 frame, not quite as thick as the standard Model 21 frame when measured from the finger grooves to the back-strap area. All other dimensions seemed similar to the original. Much to our surprise both frames weighed in at exactly 5.4 ounces so there was no weight advantage either way, just a little more comfortable fit for someone with smaller hands.

The .45 ACP complete barreled slide of the factory Model 21 weighed in at 1 pound, 5.1 ounces. The .50GI complete barreled slide weighed in at 1 pound, 6.8 ounces resulting in just a modest increase of 1.7 ounces for the .50GI.

The guns were weighed complete with their full payload of ammo and a magazine with extension. The .50GI and its 10 rounds tipped the scale at 2 pounds, 8.3 ounces while the .45 ACP with 13 rounds came in at 2 pounds, 6.6 ounces. Once again, a difference of exactly 1.7 ounces so it seems that there is no discernable difference between component weight and carry weight when fully stacked. We were surprised to find these results and thought they were worthwhile to mention in this context.

Range Time

Since we had spent a considerable amount of time with the .50GI round in the previous testing of the Model 1 we were anxious to get to the range. We wanted to use a familiar firearm as a baseline so we also brought an unaltered Model 21 in .45 ACP. Several groups were fired from each platform for general familiarization by all shooters. The general consensus was that while the muzzle blast is significantly more prominent when running the 275 grain JHP .50GI than the 230 grain FMJ .45 ACP ammo, the recoil is not much more noticeable. The .50GI conversion uses a much stronger recoil spring that easily compensates for the increased return forces making shooting comfortable.

In basic accuracy testing, several 5-round groups were fired from each firearm. (We usually like to fire full magazines for these tests but we were running low on ammo by this point in the testing phase). Shooting at a practical distance of 10-yards, standing, the groups were all in the same general size with no deviations swinging towards one gun or another.

With general function testing out of the way and practical accuracy testing completed; we still needed something to really illustrate the difference between the performance of the .50GI and .45 ACP rounds. In the absence of ballistic gel for this outing we resorted to another useful visual. The Small Arms Research test facility has many unique targets used for numerous types of testing and we decided to bring out a “range car” for the next test. The range cars are used in testing performance in firearms and ammunition where such factors are requested as penetration, deflection, fragmentation on solid materials, etc. In this particular test we thought it would be useful to illustrate the differences between the .45 ACP and .50GI when fired from 10 yards into a mid 1990s Pontiac Grand-Am. We fired two rounds of each type of ammo into similar spots and photographed the different characteristics. The first volley of rounds penetrated the rear door and into the skeletal automatic window mechanism. While the difference in the rounds is obvious in their entrance holes, they were both stopped by the steel bracing that controls the window mechanism and did not penetrate the inside panel of the door. In the second volley of rounds we chose spots in the same door where they were unlikely to encounter any additional mechanical devices and the results were immediately obvious. Both rounds easily penetrated both layers of the first door and debris movement was obvious in the back seat area upon firing. When examining the car after this second round of testing we quickly located the .45 ACP projectile, almost undistorted, on the floor in front of the back seat. To our amazement however, the .50GI projectile continued to travel through the opposing inside door skin and clean out the opposite side of the car with enough energy to peel a large opening on the way out.


With a little concern for overusing a common cliché, we just have to say that the .50GI conversion for the Glock handguns provides a lot of bang for your buck. This conversion is certain to appeal to many people for many reasons. The Glock aficionados are going to have the benefit of a serious caliber conversion as a simple drop-in mechanism to the same gun they already may own. Others like this writer (a long time Model 17 owner) will buy a Model 20 or Model 21 just to have a new host for this kit. Used and trade-in Glocks are quite common since so many large police departments upgrade to later generations as they are introduced, and the prices of the used guns are often extremely attractive. When combined with the low $595 MSRP pricing of the Guncrafter Industries .50GI conversion kit it is almost like having 2 guns for the same price as a single, new one.

If you are on the fence of purchasing a .50GI conversion kit for your Glock and you are reading these pages of Small Arms Review, it is fair to assume you may be interested in a little inside info regarding the .50GI and a connection to the NFA world. During a conversation while undergoing testing for this article we were left with this little tidbit while talking to Guncrafter Industries CEO Alex Zimmerman and we mentioned how interesting this would be if a threaded barrel and suppressor were available since it is already big and subsonic. An audible chuckle could be heard over the phone and the last words Alex muttered were: “We’re working on an interesting project like that right now and have been testing this combination for quite sometime already.” Just a little food for thought - so stay tuned.

Guncrafter Industries
Dept. SAR
171 Madison 1510
Huntsville, AR 72740
Ph: (479) 665-2466

This article first appeared in Small Arms Review V13N12 (September 2010)
and was posted online on March 9, 2012


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