Here's the details. M71 Mauser carbine sporter, bore is beauiful. This is my first BPCR, and first one I had to make and form brass, so I know the problem is with my brass.
I started with new Starline 45-90 brass. After sizing in 43 Mauser dies, it chambered in the rifle, so I did not trim.
First time out, nothing would fire, dented primers. I put little O-rings on the top of the rim, forcing the rim to the bolt face, and it fired after that, and the fire formed brass looked good (to me).
So the 2nd time out, I'm thinking with fire formed brass, the brass would headspace on the shoulder, but it still would not fire. I had to use the O-rings again.
The brass must be moving forward on firing pin strike, and obviously, the rim of 45-90 is not as thick as 43 Mauser.
Any suggestions?
Unrelated, I think, I had one case separate at the shoulder on the 2nd firing. I did anneal (again my first) by holding with my fingers as I rolled in front of a torch for a few seconds. I can afford to lose a brass here and there, and expect it.
I am mainly concerned with not being able to fire without the O-rings.
Load..Lyman mould made for this rifle, 350gr, 85gr Olde Eynsford 1 1/2, WLR primers, SPG lube, drop tube and slightly compressed with .125 over powder card. I filled case to where the base of bullet would sit, then put in card, and seated bullet with press, so it is compressed the thickness of the card.
Thanks in advance, Dan