Question. I am considering reloading some 7.62x 54R. I have the Hornady Handbook of Cartridge Reloading, 9th. Edition. Where it states bullet diameter they show 0.308-0.312". Now I find this unusual to have such a diameter variable. How does one know what his actual diameter is? I don't have a way to measure the bore. My rifle is a MN 1931 Tula. Is this a critical issue or not? I am not a target shooter and may just want to reload some hunting rounds. Depending on the actual bore it could be either "loose" or "tight". Wouldn't want to have too much pressure using a 0.312" if the bore is 0.308". However I would prefer to use 0.308" which is much easier to find bullets for instead of 0.312" (.303") which are almost impossible to find these days. Comments appreciated.
reloading 7.62x54R
- Thread starter amber2010
- Start date
From reading around for reloading my Mosins I've read that SOME have tighter bores that can shoot down to as low as .308 with some reasonable accuracy. But more of them need a .310 to .312 size. Or for cast as much as .313.
The trick is to get a soft lead ball and slug the bore then measure the bore and groove diameter. To do this you literally hammer the lead ball in until the skirt of swaged off lead is quite thin and then use a reasonably close fitting dowel to tap the slug through and out the chamber end. Do this with a plastic or brass mallet and not a steel hammer for obvious reasons. You CAN use a steel hammer provided you don't beat the lead skirt that swages off too thin and crush through it but that's a risk you likely shouldn't take.
Measuring the slug you've just created a set of calipers that you know you can trust to within .001. Once you know the bore and groove sizes you can buy bullets to suit.
Part of the problem is that it's the Mosins that created much of this variation in size issue. So the only good way to be sure is to slug your bore.
The other good news is that if you don't have a set of calipers then it's high time you buy some anyway. You need them for measuring the OAL of your reloads and for measuring the lengths of casings to know if they require trimming or not. So if you don't have any you need to get a set anyway.
If you don't want to pay the outlandish price for a box of dead soft cast round ball then hit up a fishing supply shop and buy one of the round or tear drop sinkers that don't have a steel eyelet wire in it. Or see if someone you know that shoots round ball can spare a few to keep around for slugging bores like this. Even a .357 size cast bullet can be tapped down the bore for slugging since you're working with a smaller bore than the bullet.
The trick is to get a soft lead ball and slug the bore then measure the bore and groove diameter. To do this you literally hammer the lead ball in until the skirt of swaged off lead is quite thin and then use a reasonably close fitting dowel to tap the slug through and out the chamber end. Do this with a plastic or brass mallet and not a steel hammer for obvious reasons. You CAN use a steel hammer provided you don't beat the lead skirt that swages off too thin and crush through it but that's a risk you likely shouldn't take.
Measuring the slug you've just created a set of calipers that you know you can trust to within .001. Once you know the bore and groove sizes you can buy bullets to suit.
Part of the problem is that it's the Mosins that created much of this variation in size issue. So the only good way to be sure is to slug your bore.
The other good news is that if you don't have a set of calipers then it's high time you buy some anyway. You need them for measuring the OAL of your reloads and for measuring the lengths of casings to know if they require trimming or not. So if you don't have any you need to get a set anyway.
If you don't want to pay the outlandish price for a box of dead soft cast round ball then hit up a fishing supply shop and buy one of the round or tear drop sinkers that don't have a steel eyelet wire in it. Or see if someone you know that shoots round ball can spare a few to keep around for slugging bores like this. Even a .357 size cast bullet can be tapped down the bore for slugging since you're working with a smaller bore than the bullet.
Actually I do have a good pair of calipers. Looks like the standard surplus ammo bullet that I just pulled measures 0.311". Since that fires well in my Mosin I presume I should go with the larger diameter than the 0.308".
Thanks for your reply.
