Crimp-Glocks-Plated Bullets & Tumbling (..LONG..)

[renaissance7697]

Crimp-Glocks-Plated Bullets & Tumbling.

I have been reloading for years; many tens of thousands of rounds and several calibers for multiple platforms.
But never for a GLOCK.
(In all fairness; I DO load on the low to medium power range range for the cartridge in question)

Finally got around to loading for a Glock (in 9mm).

First thing I noticed was that "my" standard 9mm formula:
(124-125 grain round nosed & 3.4 of CLAYS)
which I had been using for years, with excellent results in:
2 Browning High Powers ('72 & '85)
Sig 228
SW 5906
Would NOT operate the Glock 17.
It apparently needed more powerful cartridges > Stovepipes & Failures to both Eject AND even Extract.

Went to 3.6 CLAYS (3.7 is "a" published Maximum)
Now the 17 functioned mechanically, but the accuracy was lousy.
I finally determined that some of the bullets were "tumbling". (observed "keyholeing" on the targets

Too much crimp???

Reduced the crimp and the problem abated somewhat.
Reduced the crimp to the absolute minimum.
(Just enough to squeeze enough of the flare out of the case so that a finished cartridge would "Clink" solidly into a Max cartridge test gauge)
[and I could NOT push the bullet deeper into the case after seating]
The bullets are now essentially "unmarked" (observed by pulling a seated and crimped bullet).
I THINK this may have solved the problem but will have to test some more to be sure.

Now:
What suddenly went wrong with my tried and true formula for 9mm?My Theory:

1) I had only recently switched from varying "jacketed"
and "Hard Cast lead" to Copper "Plated" bullets (West Coast)
Could it be that the Plated bullets, after crimping allow the
case to spring back a bit > making the crimped case mouth
dimension appear within tolerances
But
The lead under the thinner copper plating (as opposed to
Jacket) DID NOT spring back, resulting in an "undersized"
diameter
Previously:
* Jacketed bullets were stronger and resisted queezing
better
* The Hard case lead were originally a thousandth or
two larger and followed the rifleing a bit better

2) Glock has "shallow(er)" rifling [or whatever the twist in Glock
Barrels is called]
The slightly "undersized" copper plated bullet diameter
resulting from the excessive crimp
Combined with the shallow rifling
Under spun the bullets Allowing the bullets to tend to tumble

3) The higher velocity resulting from heavier loads made the
undersized bullet more likely to strip through the rifling

4) It is possible that the "cut" in the plating due to the crimp ring
might have led to the plating peeling off in flight contributing
to the tumble.

My fantasy is that a combination of 1,2,3,&4 caused my "tried and true" 9mm formula to fail in the GLOCK 17.



What do you all think?

Has anyone else run into similar problems with GLOCK's and/or Plated Bullets?

[9x45]

I use 4.5 grains of TiteGroup behind a 124 grain copper plated round nose at 1.155 OAl and a normal crimp. Accuracy is excellent and I have never had a malfunction in over 50,000 rounds...

[labgrade]

Just fer grins, use a micrometer & measure the diameter of these new bullets - see if they're on the smallish side of things ....

[Tree Rat]

I have had amazingly similar problems with Glock 17 and Berry's plated bullets. Your theories are interesting..........

TR

[Mikul]

Berry's plated rounds are soft lead with an itty bit amount of copper on the outside which is insufficent to stand up to the wonders of polygonal rifleing. If you download the cartridge, you will find a point where the bullets stop tumbling. You will also find that the Glock won't cycle.

Two options:
1) Go back to jacketed or hard cast lead.
2) Get a lighter recoil spring for your Glock.

[Tree Rat]

Never pushed them hard by any account. Almost always around 125PF with a 13 lb recoil spring (standard is 17 lb). Went back to Star FMJ's, and to the extent I shoot the Glock anymore is minimal. BTW, never had the problem with my H&K USP's.........

TR

[john kilgore]

MIKUL is right:

Welcome to the wonderful world of Glock-PERFECTION !

The problem you're encountering is due to the polygonal rifling. The best way to deal with it is to install another barrel with conventional rifling.

Installing lighter springs to accomodate lighter loads might bite you with a damaged gun or significantly shortened gun life if you revert to standard ammo and don't replace the spring.

Barrels are as inexpensive as $70 dollars up to $250, and almost all will improve the accuracy over the stock barrel.

Don't take this as a flame against the Glock, as there are original guns with over a million rounds fired thru the barrels that still exhibit serviceable accuracy (~6"@25yds).
However, they don't handle cast or some plated bullets well. I've had good luck with the 9mm with a 124 TC cast bullet @ .356" loaded over 3.5gr of Bullseye. This just will operate the action, and gives acceptable accuracy (4"@25yds) for about 50rds after which the barrel requires brushing.
The same load in a .40S&W (3.5 Bullseye) with a 180 TC cast @.401" works about the same.
These are the only 2 loads for these two calibers that I can recommend as the Bullseye powder gives sufficient recoil without running up the velocities and pressures past the accuracy destroying level while still cycling the actions.
I've also had good luck with the Rainier bullets as well as the Speer Gold Dots (both plated bullets but thicker than the Berry's), with the stock barrels.
Good luck !!

[Tree Rat]

Hey.............Did I mention not having the problem with USP's?

TR

[9x45]

Any of this could also be caused by limp wristing. Let an experienced Glock shooter try your loads.

[Archie]

Years ago, I loaded up some 38 Specials and shot them from a Blackhawk. I had perfect profiles of a 158 grain SWC at 15 yards. When they connected with paper at all.

They also leaded like crazy.

I never did figure it out, but the prior and the next time time I used that exact formula (Unique, I think), accuracy was pretty good.

I think it may have been a bad batch of bullets. Possibly undersized.

Like someone mentioned, mike some of the bullets.

I personally find it unlikely that decent lead bullets would strip in the rifling, let alone plated bullets. I've used several different plated bullets with good results.

And by the way, limp-wristing will keep your autopistol from cycling; but it won't make bullets keyhole.

[Redneck2]

on a continual basis will also get you beat up in some of the bars around here...

[MADISON]

I can't/won't help you with loading data. My Glock 21 [45ACP] loves hot loads. I have used the over max..7.3 gr. Unique with a 230 JHP down to 5.0 gr of Win. 231 All shot well.
I taper crimp my PLATED BULLETS using a medium crimp, so as not to cut into the bullet.

[WESHOOT2]

9x19 for Glox = any case (prefer IMI, Speer, W-W, R-P), any primer (prefer CCI500), any 124/125g (prefer Rainier 124g TCJ-RN), OAL 1.140-1.160" (prefer 1.145-1.155").

Powder = 6.0g Power Pistol.
Crimp = LEE Carbide Factory Crimp die.

[jtduncan]

My favorite 9mm loads that work in all of my guns past and present including:

BHP
Glock 17/34/19/26
HK P7 PSP and M8
HK USP
Sig P226 and P228
Marlin Camp 9
Colt 9mm AR
Olympic Arms PCR-9 AR

4.2 grains of TiteGroup with Rainier 124 grain FPIn 9mm

3.4 grains of TG with a 147 grain RAN CPHP @900 fps subsonic - not a plates load but great accuracy

I prefer to shoot 115 grainers in 9mm since I can easily bump up the velocity. The 124s were created to add some FPE but never do and the 147s were designed to hold their trajectory longer for 9mm carbines like the HKMP5 and be quiet hence the sub 1100 fps speeds on the 147s.

Load all of my 9mm to 1.15" OAL and lightly crimp with a Lee factory crimp die.

My favorite 9mm recipes:

4.5 grains of TG with 115 grain RAN or Montana Gold JHP @ 1120 fps) - great target and plinking load.

4.7 of W231 with 115 MG JHP @ 1100 fps

6.6 grains of Power Pistol and 115 grain MG JHP - very best @ 1250 fps in a Glock 17 4" barrel - great steel plates load.

With Glocks, you need at least 1,100 fps in 9mm to cycle the slides and get some good accuracy. they were designed around NATO ammo which is hotter.