Parabellum Research PBR V Supreme 165gr FMJ (from Chucky2)

[chucky2]

But it's not outside the design spec of 10mm right?  What I'm working towards is this PBR isn't something so hot on the 10mm scale that a 10mm pistol shouldn't be expected to handle it, right?

[The_Shadow]

The PBR 165 grain V Supreme is well inside the realm of realistic 10mm ammo and inside the SAAMI MAP for 10mm ammunition.

As mentioned the Speer #14 book shows 165gr bullets loaded with 10.0 grains of Power Pistol @ 1314 fps from S&W1006.
Alliant 2006 shows;
155 JHP loaded with 9.5 grains of Power Pistol @ 1,320 fps 33,000 PSI well below the 37,500 PSI adv.
180 JHP loaded with 8.7 grains of Power Pistol @ 1,240 fps 34,900 PSI well below the 37,500 PSI adv.

[chucky2]

Ok, then what I think I'll do is also reference this thread to the Glock guy when I e-mail him back, along with a couple of others.  I really do wonder what ammo Glock tests with when they test pistols sent back?  I've heard 200gr Blazer, but just no way to confirm unless they in fact did so.

[The_Shadow]

We did test the CCI Blazer 200gr 1050fps / 490 ft. lbs Low to medium power for 10mm
http://10mm-firearms.com/factory-10mm-ammo-pull-downs/cci-200-gr-tmj-pull-down/

Alliant listed 200FMJ Power Pistol 7.7 @ 1,145 fps - 35,600 psi from 5.5" bbl (well below the SAAMI 37,500 adv)

[chucky2]

Here's another question I'd have for Glock:

What ammo do you use to QC test a new design like the Gen3SF or Gen4?  Certainly we know that most off the shelf 10mm ammo is watered down, such as the 200gr CCI Blazer you linked below.  So what full power 10mm, such as this PBR, are they using to ensure their design can handle full and top power 10mm, along with that % over top power 10mm to ensure the design handles everything?  I wonder if they roll it in-house, private contract it out, or order the same stuff like Underwood and/or PBR that we order?

[The_Shadow]

Did you have the two pieces of tested empty brass/aluminum cases in the manila envelope in the factory box?  It would have a headstamp of the manufacture of that ammo used for the test shots.

Mine were aluminum CCI...I do not know if they have a contract for a specific loading or if it is the same as off the shelf to the public.  Some companies test to a proof pressure value for barrel testing...

Proof Pressures for 10mm are 130% minimum and 140% maximum as set by SAAMI
The formula is based on the Maximum Portable Lot Mean MPLM of 38,700 psi
38,700 x 1.30 = 50,310 psi  and 38,700 x 1.40 = 54,180 psi
Minimum and Maximum
50,310 psi - 54,180 psi  these would be rounded to 50,500 psi - 54,000 psi

I seriously doubt that Glock is using proof rounds for firearms function test, and those aluminum cases don't show any signs of that high of pressure based on what I have personally tested and measured the effects of higher pressure rounds.

Glock seems to load two rounds in the magazine, rack the slide, looking for it to feed to the chamber and fire, ejecting that casing and looking for it to pick up and feed the next cartridge to the chamber and fire that one and eject it as well.

That is just a simple function test, do they study anything with regards to spent brass, looking for extractor marks or ejector marks, case expansion other, I don't know.

Being a handloader, and testing in various 10mm guns over the years has shown me many things, especially when loads approach higher pressures.  Brass that fully expanded to chamber size(for the Glock this is 0.4340" at the start of the extractor cut), have seen ammo that started the flow at the feed ramp what we call a "SMILE".  I have tested some ammo (Underwood) that blew primers out, locked the slide back but left the spent casing in the chamber. 
My handloads for the higher power applications are on up there, but backed off from the point of "Smiles" and popped primers for added safety and reliability.

[chucky2]

Yes I've got them...somewhere...   I'll have to track them down and see what they say.  Even if they're CCI though, we don't know what loading they had.  I am thinking more of from a design perspective.  I've got to think that when Glock did the Gen3SF, and then the Gen4, they just didn't make whatever design changes and then not test the pistols against a full QA workup, looking for problems like I'm/We're having with the Gen4.  I'd be curious to know what medium to hot loadings they used (I'd expect that to be in the thousands of rounds, so they'd have used quite a lot) to ensure that over the expected life of the pistol there would be no issues.  For example, we all know Underwood is loaded very hot.  I'd expect Glock to perhaps maybe not actually use Underwood, but, at least, use hot loadings like Underwood offers to ensure that their pistol not only functions reliably, but, lasts, using ammo that is at the top of - but within - the 10mm spec.

[DAVIDF]

Someone with both give it a go and report back 

Intercooler,

I have both Gen3 & Gen4 mags. Can't tell a difference in either the Gen4 20 that I had problems with or the Gen3 they replaced it with that has been flawless. When I had the Gen4, the PBR 165gr velocity extreme worked the same in both mags. Haven't had any PBR to try in the Gen3.

The_Shadow & chucky2,

When I returned my Gen4 the 1st, Glock had only CCI Blazer 10mm to try in it. Not a custom load for them by CCI, just the off the shelf loads. Then, when I sent it back later they received some Hornady 180gr XTP loads that they used to test mine. I think they just use whatever large manufacturer's ammo that they can find. They refused to try mine with something like Underwood even if I sent it to them.

[chucky2]

So when they tested with the Hornady, did your Gen4 FTF?