Glock Major 9 Questions

[iainmcphersn]

I really need to get some input on how to read pressure signs with a comped Glock. I have a fair idea of what level of primer flattening reads as high pressure with a standard Glock barrel but I know shooting a comped barrel is different.

I got a KKM barrel and 4 port comp last week and today was my first day to run a few rounds through it. I have been shooting Titegroup and 115 - 124 grain bullets but had a pound of Longshot on the shelf that I used to make up some "maybe" major 9 loads. I loaded out several charge weights, expecting to start with the lighter charges and look for pressure signs, stopping when I started seeing them. The odd thing is that I did not see what I expected to and got a little confused about what I did see. I got a fair amount of smoking on the cases which I usually associate with a very light load, one that does not expand the brass enough to seal the chamber correctly. On further reflection, I realized this might be related to the forward pull from the comp holding the action closed longer and not a sign of low pressure. I did not see any flattening of the primers around the edges and no excessive shaving from the firing pin window. The brass fell pretty close to the gun and was warm but not hot immediately after firning.

I'm running a 2nd Gen Glock 17 with an old standard recoil spring, The loads are once fired Federal brass, CCI Small Pistol primers, 124 gr fully enclosed truncated FMJ. Charge weight ranged from 6.3 to 7.4 grains.

Any input would be greatly appreciated. I searched for this information on the forums but did not find anything right on target. If there is something I missed, please let me know.

Thanks,

John

[Carlos]

My Glock/KKM barrel was built by John Nagel & I have had good luck with N-350 and 3n38 though the latter is quite compressed at 1.160" OAL; I only use 124 grn bullets - pref. Montana CMJ 124s. I have done a small amount of testing with Power Pistol (severe blast) and TrueBlue (friend's load).

[George]

Need to also hear what velocities you are getting over a chrono with what charge weights to say whats up.

If you are getting 1150-1200 fps with a 115-124, you are nowhere near any issues. If it's 1450-1500fps you are getting, then it's an entirely different story. The V is what you are loading for so you have to measure it and report it for any sense to be made here.

Medium fast powders usually want 8+ grains under a 124 to get near major in the 9x19 at 1.155" OAL. Slow powders will bulk out more and need compression typically.

You need to see 1340fps+ to make major with a 124gr. 1440fps+ will be needed with a 115gr.

Get thee to a chrono ASAP

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Regards,

Edited October 23, 2005 by George

[Harmon]

chronograph them loads.

try some power pistol...longshot should be good too.

[iainmcphersn]

Thanks guys, I'll see if I can get them chrono'd and post the results.

John