case bulge questions...help??

[jerryballs]

I am loading 9mm for my STI open gun. The load is as follows:

1.060 oal
federal small magnum pistol primers
4.6 grn w231
hornady HAP 125grn bullets
starline brass (new)

I am getting some bulge on my case..not major (see pic). Is this caused by the magnum primers and the low seat of the bullet?

I am also getting a nick in the base of the case from my chamber which hasn't done this before...What should I be looking at?

[Ukiahgunnut]

Why are you using Mag primers for a 9mm? I have been using regular, small pistol primers when I reload my 9mm.

Dave

[Sub95]

what kinda gun you shooting these out of?

you are probably at max load with the magnum primers, and with a lower oal given you more pressure then max load.

hodgdons has

125 GR. SIE FMJ Winchester231 .355" 1.090" 4.4grs 1009 24,600 CUP 4.8grs 1088 28,800 CUP

[jerryballs]

Why are you using Mag primers for a 9mm? I have been using regular, small pistol primers when I reload my 9mm.

Dave

I had 2,000 extra and was told that it should be fine...I guess I am learning the opposite

[jerryballs]

what kinda gun you shooting these out of?

you are probably at max load with the magnum primers, and with a lower oal given you more pressure then max load.

hodgdons has

125 GR. SIE FMJ Winchester231 .355" 1.090" 4.4grs 1009 24,600 CUP 4.8grs 1088 28,800 CUP

Coming out of a 9mm STI with 4 port comp. I think you are right. The lower seating is upping the pressure? I thought that might be why....Read 1.060-1.078 out of the hornady manual.

Thanks for the info...I will adjust and see what happens.

As for the nick in the case, would you attribute that to extraction? or sliding into battery because the short length?

[Sub95]

if it were me loading these, i would back off the powder 0.5grains and leave everything thing else the same and see what it does from there.

what does a fired primer look like? post a pic of it if you can.

the nick could be from sliding into battery hard not sure.

[G-forceJunkie]

With the magnum primer, that sounds pretty hot. I typically ran 4.4 of 231 under a 124 TMJ and win small primer.

[checkenbach]

The nick is most likely from the ejector. Definitely lose the magnum primers!!!!

[jerryballs]

Awesome! Thanks everyone... I will make some adjustments and check back tomorrow

[Whiterabbit]

I kinda like sub95's advice. Looks like you are pushing the limits everywhere. bullet very deep, powder just over spec, and a mag primer.

If you want to keep the mag primers and if the low seating is needed to cycle (I don't know what works in your gun), seems like good sense to back way off on the powder and work back up till the bulge is either visible but not measurable, or measurable but not visible (basically the first first first showings of the bulge). That'll tell you what is just a smidge over "max" to play with.