The Unofficial P64 Resource Forum

I've been hand loading for my P64 using cut down 9mm Luger cases, AA #2 and the Meister 95 grain lead bullets, .965 OAL. I have the 22lb recoil spring on my P64, never shot it with the stock spring.

So at 3.6 grains (the starting load) of AA #2 I get failure to go into battery pretty consistently. The gun is just slightly out of battery. I find that the extractor is sitting behind the case, not engaging the rim like it should. Drop the mag (or else I get a double-feed), rack the slide (round stays in the chamber) and the extractor snaps over the rim allowing me to continue shooting.

Running a 3.8 grain load of AA #2, I find myself wearing some powder. There is noticeable blowback of unburned powder. Not tons, but enough to make me stinky after a range session. No failure to go into battery like I've described.

So this weekend I loaded up 50 rounds using 3.7 grains of AA#2. I had no blowback of unburned powder, but one hangup of the extractor like I've described.

So is the recoil spring too strong for these light loads? Is the spring not allowing the slide to recoil far enough back to generate the force needed to chamber the next round correctly?

Or is there something wrong with the extractor? Is it too stiff or something?

And why can't I get near the 4.0 grain max of AA #2 without wearing a lot of powder? Seems the stronger recoil spring should hold the breech closed longer.....

I may switch back to the stock spring and see if I have problems with the 3.6 grain load. Any other ideas?

Maybe a different powder would do better? Different powders burn and act different from what I have seen.

There is a difference in the extractor groove between the 9mm Mak and 9mm Luger cases. So, when using cut down 9mm Luger cases, the extractor may not engage the extractor groove of the case properly. Something to look into. You can read more about it if you search Google a bit.

fish

failure to go in to battery , try seating your bullets in a little more, I suspect the bullet is grabbing the rifling , seat it down until it doesn't

NORM

Cool, looks like I have a few things to try!

Different powder - anybody have the HS-6 data from Speer #14 they could share?

Case differences - I saw Starline Mak cases at the last gun show $18/100. I may give those a try.

Seating the bullet deeper - the minimum oal for that AA#2 load is .955. I'll give that a try too.

Thanks!

fish
its auto loader you can't go by what it say in the manual . for seating depth, they don't tell you what type of gun the shot it in , chances are it was shot in a pressure barrel witch is a bolt action

http://data.hodgdon.com/main_menu.asp

NORM

Doesn't seating the bullet too deep contribute to overpressure conditions? When a specific load specifies an OAL, I treat that as an absolute minimum. Seating longer up to max is OK, but less than that reduces case volume and causes overpressure. Am I missing something?

fish

yes that's true in rifles and revolvers not so much with an auto loader's
,for one thing in auto loaders where you place that bullet ,can make it fail to feed ,or jam up the next bullet, all ways start with your lowest loading date and work up, I had bullets rack by hand and work fine but they didn't function at all when fired ,, they may not have to go in but 1 1/2 mm ,it won't cause that much pressure 1/2 of a mm can cause a jam, the loading starting points are way lower than factory ammo
if the bullet is out to far and the gun doesn't work what good is it

NORM

Ya that makes a lot of sense. Thanks Norm!