_N4Z_
Member
I have two M39 Mosins, one is a 1942 Sako, and the other is a 1942 B. I acquired the B in unissued condition with a new bore. My Sako has been well used. I have been cutting my reloading teeth on these two rifles. I have had exeptional results from both, but also a good share of not so great results.
I've tried multiple bullet brands and weights, and a couple different powders. All the same brass and primers. Also use a Lee Factory Crimp die with my latest loadings.
The B barrel has gotten the most attention, and as I said earlier it has printed some outstanding groups. But consistancy is lacking. I can get a lot of rounds churned out that all have the same weights and OAL's, go to the range and shoot, and get just head shaking results. First group may print sub 1", and the next may bound up close to 3" or more...:banghead: It is frustrating. I know how to shoot and have been at it a long time, so my variations to the equation should be minimal.
So the other day I picked up a bit about checking out where your COAL should be by individual rifle. Seat a round long in a fired case, and then chamber it in the given firearm. The rifle should push the bullet back further in, and when you extract it.. WAH-LAH! You've got your chamber length. Pull it back .015 or so, make sure it still fits the magazine, and giddy up. Now I have been using manual callouts, and commercial round measurements to set my OALs. Was I in for a surprise.
I checked the Sako first and most of the rounds I use in it could handle an OAL slightly longer then where I had been seating them. Good deal.
Then I checked the B barrel. WOW, does this thing have a huge chamber! Most x54r loadings call for OAL's from 2.8something inches for softpoints, to around 3.01something inches for fmj's and hpbts. After measuring and remeasuring it looks like my B will take softpoint Sierra ProHunters (180gr) out to 3.08 inches. And the MatchKings can seat out past 3.1 inches!
Are there any people here with B barrels, or any other Finn Mosin, that have such large chambers, or do I have an oddball?
I've tried multiple bullet brands and weights, and a couple different powders. All the same brass and primers. Also use a Lee Factory Crimp die with my latest loadings.
The B barrel has gotten the most attention, and as I said earlier it has printed some outstanding groups. But consistancy is lacking. I can get a lot of rounds churned out that all have the same weights and OAL's, go to the range and shoot, and get just head shaking results. First group may print sub 1", and the next may bound up close to 3" or more...:banghead: It is frustrating. I know how to shoot and have been at it a long time, so my variations to the equation should be minimal.
So the other day I picked up a bit about checking out where your COAL should be by individual rifle. Seat a round long in a fired case, and then chamber it in the given firearm. The rifle should push the bullet back further in, and when you extract it.. WAH-LAH! You've got your chamber length. Pull it back .015 or so, make sure it still fits the magazine, and giddy up. Now I have been using manual callouts, and commercial round measurements to set my OALs. Was I in for a surprise.
I checked the Sako first and most of the rounds I use in it could handle an OAL slightly longer then where I had been seating them. Good deal.
Then I checked the B barrel. WOW, does this thing have a huge chamber! Most x54r loadings call for OAL's from 2.8something inches for softpoints, to around 3.01something inches for fmj's and hpbts. After measuring and remeasuring it looks like my B will take softpoint Sierra ProHunters (180gr) out to 3.08 inches. And the MatchKings can seat out past 3.1 inches!
Are there any people here with B barrels, or any other Finn Mosin, that have such large chambers, or do I have an oddball?