OT - Chrono Day At Last

[COSteve]

I've been meaning to chrono two really hot 10mm loads I developed for my G20L about a year ago. This morning, before it got really hot, I finally got off of my butt and went to the range with my chrono. I set up my rig at our 100yd range with the chrono 14ft from muzzle and here's how it went.

Range conditions: 6,100ft asl, temp 79°, no wind
Chronometer: Shooting Chrony Beta Master with sky screens employed
Pistol: 6" barreled G20L custom Glock with 20lb ISMI recoil spring on ss captured rod
Strings Measured: Two ea. 10rd strings fired of each bullet weight and then averaged for velocities
Aiming Aid: Pistol fired from a rest while aiming at a 9" dia paper plate with 1" orange dot placed 3" from top

Load: 165grn Speer Gold Dots over Power Pistol in new Winchester cases with CCI 350 (LP Magnum) primers
Results:
Low: 1,569fps
High: 1,607fps
Aver: 1,587fps generating 923ft/lbs of muzzle energy!!!

Load: 180grn Speer Gold Dots over Power Pistol in Win cases with CCI LPM primers
Results:
Low: 1,461fps
High: 1,498fps
Aver: 1,479fps generating 874ft/lbs of muzzle energy!!!

My pistol cycled without any issues with no FTF or FTE or stoppages of any kind. In all, I shot six of my 17rd mags full of these loads and my Glock just shoots these as if they were 40s&w WWB loads. Its almost as if it were bored with me trying to impress it with these hot loads. Accuracy was also very good with all rounds staying within a paper plate target (9" plate) set at 100yds behind my chrono I used as my aim point. These loads are extremely flat shooting with a bullet drop under 3" over the 100yd flight.

The recoil was very manageable with negligible muzzle flip and once again, I's surprised that these high velocities don't create significantly higher felt recoil or significant muzzle flip. Felt recoil and muzzle rise is still significantly less than SAAMI spec 357mag loads in my Uberti 7.5" SA Cavalry model held two handed. There simply isn't the sharp jerk up as with the steel framed SA, but rather simply a strong push to the rear making this load easily controllable which still never ceases to amaze me.

These are stout loads for sure with some primer flattening but nothing close to primer piercing. The cases didn't stretch nor was there a noticeable bulge at the feed ramp position; read no Glock smile. I'll reload these cases with my mid level plinking loads again. As any loads at these levels would be hunting rounds where brass recovery was unlikely, I see no brass issues with this load, however, I wouldn't feel comfortable loading them again at this level just for safety sake.

I also tried some defensive and one handed shooting with these loads on our course, including double taps. These high velocity loads simply aren't difficult to control in my G20L longslide as the recoil energy seems to be absorbed by the extra slide mass. There is less muzzle flip with this load in my G20L than with my hot 40s&w loads using Titegroup powder in my stock G22. I believe that the slower burning Power Pistol powder coupled with the longer muzzle and additional 4¾ slide and barrel weight work together to dampen the recoil impulse significantly. The end effect is to create a an extremely heavy hitting hunting round that's very controllable in this platform.

This is pistol is now no doubt, a serious woods gun that carries comfortably all day with the magwell removed. With it, I feel comfortable engaging against anything in the Rockies, be it 2 or 4 legged. Think of my rig as 17+1 rounds of fire breathing comfort. These loads demonstrate once again that 10mm handloads using Power Pistol and magnum primers can be a potent combination when used in a longer barreled pistol.

[Terry Murbach]

WONDERFUL INFORMATION, STEVE. DID YOU HAPPEN TO TEST THOSE LOADS ALONG THE WAY WITH STANDARD PRIMERS ??
MY OLD M20 IS A GREAT SHOOTING PISTOL BUT I NEVER TESTED IT TO THOSE PRESSURE LEVELS. I THINK 140gr LFN BULLETS AT 1500fps WERE AS HIGH AS I EVER WENT IN VELOCITY.
THOSE 180gr BULLETS AT JUST UNDER 1500fps BLOW MY MIND; WOW !!!
MY GUN HAS THE STANDARD GLOCK BARREL ALTHOUGH I DO HAVE AND HAVE TESTED A 6" GLOCK BARREL IN THAT PISTOL. THE VELOCITIES WERE HARDLY 25fps HIGHER WITH IT WITH THE MY BEST LOADS SO I GAVE UP ON IT AS A HOPELESS/WORTHLESS CAUSE.
SO, IF I UNDERSTAND CORRECTLY YOUR G20 HAS A LONGER SLIDE AND A LONGER BARREL HUH ?? I DID NOT KNOW THEY MADE SUCH A 10MM PISTOL.

[COSteve]

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[Hobie]

I've been thinking of trying Power Pistol in my 10mm Auto Contender barrel (14" with Choate extension) to up the velocity a bit over Blue Dot. I understand AA9 is also a good powder for the 10mm but none has been available locally for so long I've generally ignored the AA powders. Buffalo Bore reportedly uses a lot of Power Pistol. From what I've seen they get good results. Right now I need to get out and practice, i.e. empty some brass. Will likely do that after the silhouette season is over as I'm using that frame for my silhouette rifle.

[AJMD429]

I am not a 'polymer' gun fan, and the grip of the Glock doesn't feel right to me maybe because I've got long fingers. . . on the other hand, every time I see your write-ups about your 10mm, it reminds me that pretty much every other maker seems to have come-and-gone in their 10mm chambering, and/or had 'issues' with the guns holding up.

SO - if I ever get a Glock it will be a 10mm (since I prefer the 1911 guns otherwise), and if I ever get a 10mm it will be a Glock...

(Probably it won't happen unless/until either Ruger makes a semiauto carbine for it, or someone makes a levergun in it.)

[COSteve]

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[Ben_Rumson]

Love range reports!...I'm not much of a pistol shooter but I sure enjoyed your range report...Very clear and informative...Glad you've got to a point the perseverance and experimentation has given you a rewarding result.

[Spamtown_.45]

COSteve,
So you bought a longer barrel and a new slide for the G20. Did you also get a .45ACP barrel that you use on the G20 frame? What I'm trying to figure out is can you buy a .45 ACP barrel and slide to put on the G20 frame? Would you have to buy .45 mags as well and would they work in the G20 frame? I really like the idea of the G20L as a woods pistol for northern Minnesota. Not so much for the two legged predators but for the occasional black bear or varmits around the hunting grounds.
Thanks.

[COSteve]

COSteve,
So you bought a longer barrel and a new slide for the G20. Did you also get a .45ACP barrel that you use on the G20 frame? What I'm trying to figure out is can you buy a .45 ACP barrel and slide to put on the G20 frame? Would you have to buy .45 mags as well and would they work in the G20 frame? I really like the idea of the G20L as a woods pistol for northern Minnesota. Not so much for the two legged predators but for the occasional black bear or varmits around the hunting grounds.
Thanks.

Let me start from the beginning. Both the G20 and G21 share identical lowers, yes I said Identical. They use the same part numbers for every internal part on the lower except 1, the magazine. Its the slide and barrel (along with the magazine) that defines what caliber the pistol is. So, you can buy a 10mm 6" longslide and convert either a stock G20 or G21 into a G20L or you can buy a 45acp 6" longslide and convert a stock G20 or G21 into 45acp into a G21L.

In my second post in this thread above, I said that what I did was start with a German steel 6" 45acp slide to which I bought a 6" Jarvis 45acp barrel. The first picture shows what it looked like. Now, comparing the 45acp longslide with a stock 10mm slide, I found that the 45acp's breachface was 0.50" wider than the 10mm's or 40s&w's breachface as 40s&w and 10mm have the same diameter case, its just that the 10mm case is 0.125" longer.

So, I did some testing using a G22, 40s&w barrel I had to see if the 45acp's extractor claw would be able to reach in the extra 0.25" (1/2 the 40s&w's 0.50" smaller diameter) reliably and I was able to ensure the best grip by using Glock's newest extractor design, their LCI (loaded chamber indicator) version because besides the LCI block on the arm of the extractor, the LCI version's 'claw' is angled inward about 8° so that it more completely grabs the case rim vs the previous extractor design where the 'claw' was straight up.

Satisfied that I had a good chance of success, I went looking for someone to make me a 45-10mm conversion barrel. As I said in my second post, I convinced Keving of KKM to make me one. The second picture above shows Kevin's first ever 45-10mm conversion barrel. So, with my conversion barrel and some G20 mags, I proceeded to test my creation to see if it would actually work. I'm pleased to say that it did, and did very well.

Now, all I have to do to change calibers is to swap out the barrel and mags and I'm good to go be it 45acp or 10mm. One more thing you need to understand, you have to start with a 45acp slide if you want to shoot both 45acp and 10mm because the 45acp's breachface is cut to the 45acp caliber to accept a 45acp case which means that it will also accept a 10mm's case head.

You can't convert a 10mm slide to shoot 45acp because the 10's breachface is 0.50" to narrow and so the 45acp's case won't physically fit in a 10mm breachface. That said, my conversion has worked flawlessly for me for over 7 years, however, some people have found that they had failure to extract issues using the conversion barrel with a stock G21 45acp because of tolerance stacking (I think).

Further, as I've never tried my conversion barrel or anyone else's 10mm conversion barrel in one of Lone Wolf's stainless steel 45acp longslide, I honestly don't know if it will work reliably either. If it were me, if I wanted a 10mm woods gun which everyone agrees would be a much wiser choice over a 45acp woods gun, then I'd be likely to get a dedicated 10mm longslide barrel and internal assembly and put it on my large framed Glock.

[Spamtown_.45]

I think the first paragraph of your response really answers my question, although I appreciate the more indepth explanation of your conversion. Attempting a conversion like that is more than what I would like to take on as a project. I was looking for a way to get a "2 for 1" by purchasing a stock G21 and then adding a 6 in slide, barrel and mags for 10mm thus achieving a "second" pistol. From the cost of parts this may not really be cost effective. Anyway, I am beginning to really like the 10mm. It seems similar to a .45-70 in that if you reload, there is alot of flexibility in what can be achieved...soft shooting cream puff's to full throttle hot loads.
Thanks again.

[madman4570]

Nice Steve
Without a doubt the Glock is a fine weapon and that 10mm with 17rds is one deadly beast.
The bad guys back in the old days are just lucky you weren't around
you could have wiped out everyone at the OK Corral

Really friend that 10mm is good stuff.

When your as passionate about your Glock 20 and people just don't get it(Don't ya just want to shake them and say wait/listen )
I know I do with my Ithaca

[COSteve]

I think the first paragraph of your response really answers my question, although I appreciate the more indepth explanation of your conversion. Attempting a conversion like that is more than what I would like to take on as a project. I was looking for a way to get a "2 for 1" by purchasing a stock G21 and then adding a 6 in slide, barrel and mags for 10mm thus achieving a "second" pistol. From the cost of parts this may not really be cost effective. Anyway, I am beginning to really like the 10mm. It seems similar to a .45-70 in that if you reload, there is alot of flexibility in what can be achieved...soft shooting cream puff's to full throttle hot loads.
Thanks again.

That's easy. Here's all you have to do. Contact JR or Danny at Lone Wolf Distributors and tell them you want a G20 longslide upper. They will sell you a Slide (however, I would suggest you opt for the Blind Marked upgrade), a Barrel (again, I would suggest you opt for the Blind Marked upgrade), and Slide Internals (firing pin, extractor, etc.), some sights (they have many), and finally some G20 Magazines. Then its just a matter of removing the magazine and clearing the pistol, slipping off the G21 slide and replacing it with a G20LS and inserting your G20 magazines. The conversion takes all of 20 seconds.

[Terry Murbach]

THIS HAS BEEN AN UTTERLY FASCINATING OT [ PISTOL] THREAD. YOUR G20 LOOKS ALMOST LIKE MINE AS I ORDERED THE GUN [ IN '92 ??] WITH ADJUSTABLE STEEL SIGHTS AND THE PROFILE OF BOTH FRONT AND REAR SIGHTS ARE ALMOST IDENTICAL. GLOCK TOSSED IN THE NIGHTSIGHTS [ NOW DEAD] WITHOUT MY EVEN THINKING OF 'EM. THE GUN WAS SIGHTED DEAD ON THE MONEY AND IT WAS TWO OR THREE YEARS BEFORE I EVEN THOUGHT TO TEST THE ADJUSTMENTS ON THOSE BEAUTIFUL SIGHTS. THEY DID NOT GO tick tick tick, they went THUD THUD THUD, AND CAME BACK EXACTLY TO WHERE THEY'D STARTED. GREAT SIGHTS !!!
MY G20 FEELS LIKE A TINY BIT THICK 1911 IN MY HANDS BECAUSER I SENT IT TO AZ TO BE ROBERIZED, A PROCESS THAT TAKES AWAY ALL THE BULKINESS OF THAT G20 GRIPFRAME AND SLENDERIZES IT BEAUTIFULLY.
MY TRIGGER WAS DONE BY THE LATE WRITER CHUCK KARWAN AND FEELS LIKE 3 1/2lbs BUT IS ACTUALLY FIVE POUNDS. IT IS SO CRISP AND CLEAN AS TO BEGGER COMPARISON AND EVEN OLD GLOCKSTERS WHO SHOOT THIS PISTOL ARE AMAZED AT THE TARGET GRADE TRIGGER ON THAT PISTOL.
I'VE CLEANED HOUSE WITH THIS PISTOL SEVERAL TIMES IN LOCAL MATCHES, ONE TIME INADVERTENTLY LOADING THE G20 WITH 40S&W AMMO WHICH SHOT LIKE A CHAMP, HAD ALL THE RECOIL OF A HEALTHY BEER BURP, AND TICKLED ME TO NO END !!!!

[awp101]

MY G20 FEELS LIKE A TINY BIT THICK 1911 IN MY HANDS BECAUSER I SENT IT TO AZ TO BE ROBERIZED, A PROCESS THAT TAKES AWAY ALL THE BULKINESS OF THAT G20 GRIPFRAME AND SLENDERIZES IT BEAUTIFULLY.

Hello, you have my attention! My G19 is a bit long front to back to be truly comfortable and the 20/21 grips are just too big front to back, period. I'd dearly love a 20 or 21 so I have to ask...

What is Roberizing?

[Terry Murbach]

MY G20 FEELS LIKE A TINY BIT THICK 1911 IN MY HANDS BECAUSER I SENT IT TO AZ TO BE ROBERIZED, A PROCESS THAT TAKES AWAY ALL THE BULKINESS OF THAT G20 GRIPFRAME AND SLENDERIZES IT BEAUTIFULLY.

Hello, you have my attention! My G19 is a bit long front to back to be truly comfortable and the 20/21 grips are just too big front to back, period. I'd dearly love a 20 or 21 so I have to ask...

What is Roberizing?

THERE IS A FELLOW OVER IN PHOENIX AZ NAMED ROBAR WHO HAS A GUNSMITHING SERVICE. THEY DO FINE WORK FROM ALL I'VE EVER HEARD. THE SLENDERIZING OF MY G20 GRIPFRAME IS SO WELL DONE IT LOOKS LIKE A FACTORY GLOCK.

[awp101]

THERE IS A FELLOW OVER IN PHOENIX AZ NAMED ROBAR WHO HAS A GUNSMITHING SERVICE. THEY DO FINE WORK FROM ALL I'VE EVER HEARD. THE SLENDERIZING OF MY G20 GRIPFRAME IS SO WELL DONE IT LOOKS LIKE A FACTORY GLOCK.

Many thanks! I'll look him up after I get home today...