UPDATE:
Spoke to Dillon from MGM today and he said if the bulge is at the 12 o'clock position, it could be gravity holding the brass at the bottom of the chamber during the firing of the rifle. Made sense so I told him I'd hit the range next week and index some cartridges so I knew for sure where the bulge was occurring. He seemed genuinely concerned on the phone (another reason I like MGM's services) and told me his reamer is super tight and he doesn't even usually come close to the head of the cases on the factory cut 30-30 chambers, so he was baffled. I also told him the PMC ammo was the only ammo I took out with me last week and I'd take some other brands with me on my next trip.
Well, I decided to run out to the range real quick tonight just to find out what was going on. I had the same PMC ammo, Factory Remington loads, and some remanufactured ammo that had WW, Winchester and Federal cases mixed in the lot. I shot the 4 Remington cartridges first (two normal & two with the rifle held upside down) and it is definately gravity causing the bulge. The good news is these cases came out easy as pie and the case deformation was minimal. I then shot the WW, Winchester and Federal reloads and all of those cases came out slicker-n-snot too with the Federal case showing almost ZERO deformation. I then fired a couple more PMC cartridges and confirmed the PMC cases are smaller in diameter than the other brands, the cases bulged significantly at 12 o'clock and extraction was sticky again.
I think the Federal cases are going to work fine (which is great since I have half of a 1 gallon ziplock bag filled with 'em). They seem a little thicker/stronger than the other brands and if I can develope a load as accurate (or better) than what the cheap PMC ammo was shooting, then I'll be stoked!
I'll try to take some pics tomorrow of the different cases.
If you're gonna use PMC ammo for fire-firming, make sure you have a TIGHT chamber!!!
Thanks Again for the replies and I hope this helps,
Mike
Yeah, I was going to say the problem is with the PMC brass. My favorite is Rem because it has more room in it, and is as thick as it needs to be. Win and Fed are about the same brass thickness and capacity, and are frankly far sturdier than they need to be. You won't see much case expansion near the head until you are well into the danger zone with Win and Fed brass.
I use Win to form Herrett cases.
