Guncrafter .50GI Glock 20/21 Conversion Kit

Sharps40

Old Mossy Horns
Figgered I'd start a separate review. Will get to the range tomorrow. Hopefully some video from that but for now, the GCI .50 GI Glock conversion arrived with 60 rounds of fresh ammo.

My initial impressions are good and the gun assembles quick and easy, simply put on the barrel/slide assembly, insert a loaded mag of .50 GI and drop the slide. Ready to go. Dry, the new upper assembly passes all function checks. Range tomorrow.

The package...

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The Ammo....(reload data for bullets 180 to about 350g weight is provided with the gun. Brass/dies available from GCI.

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The oft vaunted 45 ACP, a personal favorite and this one is my carry load of 230g Federal Hydrashok, flanked by a pair of 50 GI rounds capped with 275g hollow points.

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Inside the box, a slide/barrel assembly with steel guide rod and spring and a 50GI magazine with extension to hold 9 rounds in the mag.

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Stainless slide. Like the Glock slide, not a single machine mark on it. Both Glock and GCI finish work is exquisite.

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Inside the slide, all seems to be perfection.

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Three of the four components needed to convert a Glock 20/21 to .50 GI.

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Inside the barrel, conventional button rifling. Good for jacketed or lead bullets. I suspect I'll be trying the 255g or heavier lead bullets soon. Wad cutters will be wonderful for hunting.

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For the time being, the platform will be this every day normal Glock 21 Gen 2.5 45 ACP. Should I like the 50 GI well enough, I may well purchase a dedicated frame for it later next year.

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Sharps40

Old Mossy Horns
50GI mag on the left, Glock 45 ACP mag on the right. Dimpled lips on the 50 GI mag are to ensure nose of ammo is presented properly to the barrel. Each round coming up the mag will assume a base forward position on the lips, ready to feed straight into the chamber.

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50 GI Slide left, slightly larger and heavier than the Glock 21 slide right. Barrel of the 50 GI is slightly larger in diameter (.650" vice .629" for the 45 ACP Barrel) but the wall thickness is slightly less on the 50 GI at .074" vice .089" for the 45 ACP barrel.

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Loaded chamber indicator on the extractor can be felt when the gun has a round in the pipe.

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The new upper, though slightly thicker, fits the glock 21 holster without a problem....no new leather to buy.

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All together. Now the extended base plate is a bit goofy looking but it gives 9 in the mag. Though I believe I'll replace it with a standard glock floor plate sacrificing one round of capacity for better looks and less bulk.

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That's it. Too bad its dark or I'd be shooting it already!
 

Sharps40

Old Mossy Horns
A fun trip to the range. 40 rounds of 275g JHP 50s fired. 39 cases recovered. I made up the difference by picking up about a 100000 once fired 45 ACP cases.

So. Recoil. Not bad. Like a 10mm in a full size or a 40 or 45 +P in a compact or subcompact handgun. But, more controllable and less hand slap than the subcompacts give your hand. Recoil, I think is best described as very slightly sharp with a touch more rise and torque than the 45 ACP +P but still controllable and easy to make hits with. As seen in the video, it hits steel quite a bit harder than the 230g 45 ACP. So. I'd have to say, the 50 GI is no Powder Puff.

My initial impression is of a keeper, likely deserving a dedicated gen 2 or 3 three pin frame.

The standard glock sights on it are useable but aweful hard to use compared to many after market options. They will get swapped out later after more practice and getting set up to reload this caliber.

I got one pinch of the little finger between grip and magazine extension. It was not to sharp a pinch and didn't raise a blister. After checking my grip, no more problems like that.

I am reasonably sure I will replace the extended floor plates with standard glock floor plates. 8 rounds is plenty and it saves about 1.25" length in the grip.

Brass flies well clear to the 5 oclock position rising high enough to smack the overhead (8 or so feet up) before bouncing down on the concrete.

Here are the videos.

Starting with 45 ACP on steel as a reference. This is standard 230g FMJ ammo at the normal 825ish FPS. I've always thought the 45 hit plenty hard. The video shows it to be true. In the second video, it appears the 50 GI hits even harder.

https://www.youtube.com/watch?v=ZDVz3iX_DR0

And here, the 50 GI on the same steel swingers.

https://www.youtube.com/watch?v=_lBPFOo5C08

Then I went to the dueling post and missed a couple of the resetting plates too....

https://www.youtube.com/watch?v=sHPqnvuNPLg

Then because its so much fun, I went back to the swingers and the dueling post.

https://www.youtube.com/watch?v=tbGed10lMCk
 

Sharps40

Old Mossy Horns
I think I'll name it Thumper. Now that other feller on the other forum said it was a powderpuff incapable of even matching 45 ACP ballistics.....mebby I'll call him powderpuff!
 

FishHunt

Old Mossy Horns
That is a nice set up. I think a set of adjustable sights are in order for the .50GI slide. If I owned one I'd have to try to take a pig or deer with the .50GI.

<>< Fish
 

Sharps40

Old Mossy Horns
4 day weekend. Practicing for retirement. 50 kit is installed and will be carrying it as the 50.....sold some car parts and I might treat myself to a stack of brass and some loading dies.

Well....I spose practicing for retirement is just an excuse to leave it in 50 cal format and carry it.....but its nice to have more than one excuse!
 
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Sharps40

Old Mossy Horns
After a half day with Thumper on the hip....carries almost like the 45 ACP configuration....as expected. But one significant exception. That dayum magazine extension.

Its longly ugly, does nothing for my grip since the frame is big enough as is, it sticks out so far that it prints badly and makes it uncomfortable to sit in the truck.

The 45 ACP mags with flat floor plate do not roll the gun forward and into my side like the fifty's mag extension does.

So, that cinches it. I need to locate a Glock 20/21 factory flat floor plate and swap it out on the fifty mag. I'll loose one round of capacity. But, I'm used to carrying 5 in a wheel gun and it should make the 50 conversion carry the same as the factory 45 ACP set up.

I think when I call GI for more magazines, I'll see if they'll scrap the extended floor plates and just send me mags with flat ones right off the bat.
 

Sharps40

Old Mossy Horns
Its coming along. Spare mag, dies and brass arrived this week. Bullets are on the way. Now to find some Unique.....
 

Sharps40

Old Mossy Horns
Some experimenting and loading this morning. Bullseye powder on hand and looking at the factory load data and some on the web, decided to start out with a load of 6g Bullseye with the 255g LSWC.

Went down to the workshop....it functions as my 12'x24' silencer. (Yer shot sounds like its a long way off, keeps the neighbors from coming unglued with unwarranted nervous nellyness). Open the window, big big oak about 5 feet from the window. Put on ear muffs, breath, aim, squeeze and the first ever I loaded it myownself 50 cal handgun SWC bullet went out the winder and into the trunk.

Gave the case a check. Slightly smaller expanded dimensions at near the base than the factory loaded ammo before firing. Primer looks good. Got some hood dents on the case mouth so, its probable a bit on the light side for the spring rate.

Loaded up 40 more for the range to function test and will have to get a 9v battery for the chronograph.

Meantime went outside with a probe and found the bullet just about 5 inches in to the live hardwood of the official backstop tree. Not bad. I'm aiming for 900ish FPS with the 255s. If doable, should provide 500ish lbs KE and plenty TKO or Momentum or however ya want to measure it. I figure at that, it'll knock stuffing outta deer and hogs during hunting season.

The first handloads.....

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The backstop....

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Sharps40

Old Mossy Horns
Email to Guncrafter and RimRock.....both have been good about responding to questions on their products.

Gentlemen,

I recently inquired on load data for the 50GI using the RimRock 255g LSWC and Bullseye/Unique powder. You were able to start me out with 6g unique. Haven't tried it yet. Have yet to find Unique locally. But, have a stock of Bullseye and as promised, my initial results. (Goal, if possible, is 950 FPS with the 255g RimRock LSWC).

The load Data:

.50 GI Case, once fired from the factory 275g loading.

255g Rim Rock LSWC

6.0g Alliant Bullseye Powder

CCI Large Pistol Primer (No issues with ignition using this hard primer)

Cartridge Overall Length, 1.216"

Crimp diameter at mouth of case, .524" (lee die as provided in the set, crimped separately from seating)

Case diameter ahead of solid web after firing ranges from .530" to .532" with the vast majority at .530". (10 fired cases checked) Primer condition, rounded edges, firing pin indent not smeared. (Photo attached).

Accuracy was just fine. Feeding, firing and extraction of 40 rounds was perfect in the Glock 21 conversion package.

Chronograph data, set one, 5 shots from 8 feet:

1. 891.1 fps

2. 872.4 fps

3. 896.9 fps

4. 886.8 fps

5. 901.4 fps

Ave: 889.7 fps

Hi: 901.4 fps

Low: 872.4 fps

ES: 29 fps

SD: 11.2 fps

AD: 8.1 fps.


Chronograph data, set two, 5 shots from 8 feet: (Shot 1 thrown out of calculations....reading was 971 fps and the chrono screens were shacking badly, I assume breeze/other interference and deleted this first shot as erroneous.)

1. 885.1 fps

2. 901.7 fps

3. 896.4 fps

4. 896.7 fps

Ave: 895.0 fps

Hi: 901.7 fps

Low: 885.1 fps

ES: 16.6 fps

SD: 7.0 fps

AD: 4.9 fps


Any thoughts? 955 fps with this bullet achievable with Bullseye powder? (I noted some "internet" data, showing upwards of 7g Bullseye with a 275g jacketed bullet at about 930 FPS. However, there appears to be no reliable pedigree for the data.....just somebodies "Chart" of loads.)

Thanks.

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Sharps40

Old Mossy Horns
Received a return email from the Owner of Guncrafter. We discussed BE and the 255g RimRock bullet. Looking over the results and determined how to proceed and when it might be appropriate to switch from BE to Unique.

For the nonce, I'll check a round each at 6.2g and 6.4g BE, primarily for case expansion and primer condition. If things look like they can go forward/upward, I'll load a string for over the chronograph and on the paper.

If it can't go higher, I'm looking at a good general use load already that provides a power factor of nearly 229.....an easy 18% increase over the tried and true 45 ACP 230g ball power factor of about 189. If the 45 ACP can swat deer close, and its been done, this easy handling 50 should do a bit better and deader.
 

Sharps40

Old Mossy Horns
Worked up to 6.4g BE today using the no permit required silencer building and the natures own green backstop oak to fire a couple test loads for measurement. Its time to load up a string and head to the range this weekend for some chronograph work, visuals and measurements.

The test load was as follows:

.50 GI Case.

255g Rim Rock LSWC

6.4g Alliant Bullseye Powder

CCI Large Pistol Primer

Cartridge Overall Length, 1.212"

Crimp diameter at mouth of case, .524"

Case body diameter after firing measures .532".

Case diameter just ahead of the solid web after firing was .5285" which is about the same expansion as the first load tested, right in there at .002" to .0025".

Primers good too.

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Sharps40

Old Mossy Horns
For reference, a factory loaded 275g JHP was fired over the chronograph at 8f muzzle to start screen. Case was then collected and measured. Velocity was 860.5 FPS.

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37 rounds of handloaded RimRock 255g LSWC were loaded over 6.4g Alliant Bullseye with the hard CCI LP Primers. 19 were fired over the chronograph. The remainder fired on target (7 yards) and steel, 7 to 15 yards.

The handload data is as follows:

50 GI Case, twice fired. 255g Rim Rock LSWC. 6.4g Alliant Bullseye Powder. CCI Large Pistol Primer. Cartridge Overall Length, 1.216". Crimp diameter at mouth of case, .525".

Accuracy was just fine. Feeding, firing and extraction of 37 rounds was perfect in the Glock 21 conversion package.

Chronograph data, 19 shots from 8 feet:

Shots 1-19: 889.8 fps/892.0/914.5/901.8/889.9/891.7/892.2/905.9/886.2/895.3/888.0/897.9/895.9/894.0/887.7/895.9/900.8/902.0/889.1

Ave: 895.3 fps

Hi: 914.5 fps

Low: 886.2 fps

ES: 28.3 fps

SD: 7.2 fps

AD: 5.5 fps.

Average body diameter (20 fired cases selected at random) of the 255g LSWC/6.4g BE loading was: .5316"

Average case diameter just in front of the solid head (20 fired cases selected at random) of the 255g LSWC/6.4g BE loading was: .5298"

Observations:

1. Ejection with 255g LSWC and 6.0g BE was erratic, cases landing in the 3, 6 and 9 oclock areas. Case mouths battered and bent. Ejection with the same bullet and 6.4g BE were consistently at 5 oclock, case mouths not battered.

2. The hard CCI primers are slightly flatter (though the edges are still nicely rounded) with both handloads than the factory loads that use the 275g JHP.

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3. Recoil of the handloaded 255g LSWC is snappier than the Factory 275g JHP though still controllable. No worse than shooting a 10mm in my estimation.

4. Point of impact with the 255g LSWC/6.0g BE was accurate but a bit erratic even at 7 yards producing two distinct groups, one above the other with about 1.5" separation. Point of impact with the 255g LSWC/6.4g BE is spot on at 7 yards. Hitting even the 4" steels at 15 yards is pretty easy to do.

5. I suspect 950 FPS with this bullet is possible but given the recoil, performance and the measurements, I believe 6.4g Bullseye with the 255g LSWC will be my working maximum for this bullet/powder combination.
 
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Sharps40

Old Mossy Horns
Income tax came back. In addition to giving most of it to the propane man for a winters worth of gas to keep us in hot water, I gave a portion to GoodWife, just to keep me on her good side and so I don't get carved up in my sleep and then went to Fuquay where I found me a nice 2000 DOM Glock 21 lower end. Picked it up for $199 and its in fine shape so.....

Got the 50 its own dedicated Gen 3 launching platform with the ubiquitous pickatinny mounting rail for the Tacticrap Corp combination flashlight laser bayonet grenade launcher.

And....got my favorite 45 ACP put back together on its original Gen 2.5 launching platform. Loaded and on the nightstand, of course.

Happy me. This should take care of the large frame semi auto itch for just about ever.

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Sharps40

Old Mossy Horns
GoodWife didn't believe me, about the whole Tactical Crap bayonets thingee.....

I'll say it up front, not mine......lifted the photo from some poor fella who does own one though....

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Sharps40

Old Mossy Horns
Numbers, for folks as like them. Many thanks to Handloads.com and Dillon for their fancy calculators so I don't have to do the math. For me, its a fun cartridge. A 50 I can shoot regularly and probably learn to shoot well. Hunting season will hopefully tell if its as effective on game as the 45 Auto (though I suspect the 3006 will be the most reliable game getter at any reasonable range!)

45 ACP, 230g, 830 FPS - Energy 351 Ft/Lbs - Momentum 27 - TKO 12 - Power Factor 190.9

50 GI, 255g, 900 FPS - Energy 458 Ft/Lbs - Momentum 32 - TKO 16 - Power Factor 229.5

41Mag, 210g, 1300 FPS - Energy 787 Ft/Lbs - Momentum 39 - TKO 15 - Power Factor 273

3006, 165g, 2800 FPS - Energy 2871 Ft/Lbs - Momentum 66 - TKO 20 - Power Factor 445.50
 
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Sharps40

Old Mossy Horns
Some more numbers.....recoil, as compared between the standard 45 ACP and my working load for the 50 GI.

45 ACP. 230g. 830 FPS. assuming a 6g powder charge and a 1.3125 lb weapon.

Recoil Impulse in (lbs sec): 0.95

Velocity of recoiling firearm (fps): 23.39

Free recoil energy in (ft/lbs): 11.15

50 GI. 255g. 900 FPS. assuming a 6.4g powder charge and a 1.3125 lb weapon.

Recoil Impulse in (lbs sec): 1.13

Velocity of recoiling firearm (fps): 27.77

Free recoil energy in (ft/lbs): 15.71

I spose it all means that the 50 GI load I made up kicks a bit harder than standard 45 ACP ammo.
 
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Sharps40

Old Mossy Horns
Yes....2 shot extensions gone.....flat bottom Glock floor plates with late model flat floor plate locks and....

The magazines still hold and function with the same 9 round capacity as the excessively bulky and ugly 2 shot extensions

And......

The gun with a flat bottom magazine rides a dayum sight better on the belt all around and even when seated in the bucket seats of the car and truck.

Very much happier!

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Sharps40

Old Mossy Horns
Glock. Slide peening. (frame flex, locking block contacts slide ways, legs of locking block marks/peens slide way)

Couple notes. It happens on all glocks. The position of the locking block and the flex in the polymer frame at that point causes it. Its normal. In heavy calibers it can be more pronounced than in lighter calibers.

Typically, the peening of the slide ways is ignored and its cosmetic only. Occasionally, it raises an burr inside the slide that is objectionable but usually only cosmetic. Peening proceeds quickly to a maximum point and then effectively stops causing no functional or reliability issues. However, some owners may find they can't ignore it.

Glock owners have several choices where slide peening is concerned. Ignore it. Stone off any burr that occurs both in the slide way and to the inside of the slide where the square end of the barrel resides. Trade for a gun that doesn't flex in a manner that lightly peens the inside of the slide ways.

Essentially, it occurs, most never notice it.

Here on a 45 ACP Glock 21 made in the 90s. Lightly peened. Except for silver spots in a vast field of black, hardly visually noticeable and barely felt by a finger.

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And here on a 50GI slide. Slightly more peening but essentially done growing. I found a burr to the inside that rubbed the barrel chamber end on disassembly. I stoned the burr off. I expect no further significant peening and will probably check once or twice more for burrs and then ignore it altogether.

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Sharps40

Old Mossy Horns
The glock factory - bar is installed in both the 21 and the 50. Variously referred to as -, 3.5lb 4.5 lb, its one of many parts and springs that can be juggled in the glock to change the feel of the trigger. It doesn't by itself provide a 3.5lb trigger. What it does do is eliminate most of the wall you hit at the rear of the stroke. Both guns take up and break cleanly at about 5.5 lbs now. (I'd always found the 5.5 lb factory trigger was closer to 6.5 or 7 lbs). The feel is totally different. Time now to hit the range with both.
 

Sharps40

Old Mossy Horns
So. Got an email back from Guncrafter. Nice to know information. The magazine, with flat Glock factory floor plate will hold 9 rounds. Just like the magazine provided with the upper unit but having the Scherer +2 floor plate holds 9 rounds.

The difference is that with the flat floor plate, the magazine spring will be at max compression and there is some risk that the wires will overlap and drag or bind a bit.

I've not noted a problem yet with 9 rounds in the mag and a flat factory floor plate. I load 9 in the mag and cycle one into the chamber immediately. I'll post up if I ever get a jam that is suspected to be a spring bind problem. (I was even thinking of clipping a coil from one of the mag springs to see if they were heavy enough to continue working but make them a touch easier to load/top off.)
 

Sharps40

Old Mossy Horns
Got the good sights on it finally, Truglo Tritiums and I can highly recommend both them and the truglo glock front sight wrench. All fine quality.

Now, Friday is clean up the yard and the truck and the car day but Sat....off to the range to shoot the 50 GI and Young Man Afraid and Goodwife's KSG!

Gonna be a lovely weekend.

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Sharps40

Old Mossy Horns
Put another 89 rounds down the pipe today. The 255g LSWC at 900 fps is right on the top of the new TruGlo front sight from 3 to 10 yds. Working back to 25 yards, I can generally topple the steel with a good 6 oclock hold. 15 yards and the 4" swingers on the dueling post are in danger with a dead center hold. Overall its good.

Shot 89 and recovered 88 rounds of brass for reloading. A thorough look for expended brass is a must with this boutique cartridge and of the initial order of 260 rounds of brass, I've fired in the neighborhood of 300 rounds and only failed to recover 4 cases.

Someone will get one in their 45 acp pickups one day and get a big surprise when it fits the shell holder but just won't go up in the die.

For now, I'll have to pronounce the truglo sights a success and say, 89 rounds is a pretty good workout with Thumper. I'd think for now, its about the limit of what I can fire in a session without working myself into a flinch. Not harsh recoil but it accumulates and does fatigue overall.

Oh yeah.....the handloads feed great and even though the load is not "listed" in any cookbook, I'm satisfied I've worked up a good functional load with Bullseye powder and this bullet. It'll be time soon to get to 900 fps or more with Unique.

But, as is, I'm pretty satisfied I'll be practicing with it all summer and ready for a deer and hog out to 25 yards or so come fall.
 
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