7.62x54R bullet diameter

[GHinNH]

I found a very old thread here, so I thought I would open this subject back up for my clarification as well as any other newer folks.

I have seen .308/.310./.311/.312(Wikipedia) and even larger mentioned. The most common seems to be .311 diameter. Is their a way to measure a barrel without a gunsmith involved?

If anyone loads now, or has some factory ammo and would care to measure the diameter, the results would be appreciated.

 

[troy fairweather]

I've seen as bag as .317 learn how to slug your bore,

 

[dh1633pm]

What he said. I did both my nagants.

 

[entropy]

Yup, slug the bore. All Mosins will fire .308 diameter bullets, though with less accuracy as bore diameter increases. I found .310-.311 bullets the best compromise between my Mosins.

 

[mdi]

To know for sure what bullet diameter to use in your rifle, you have to know the ID of your paticular rifle's barrel. The easiest way is to slug the barrel. I've slugged the barrels of all my guns, except rim fire because I won't be casting any bullets for them...

 

[troy fairweather]

if your worried about slugging the bore with lead, a crayola crayon is the perfect size for 30 cal. Cut off a 1/4" peace and push it down the bore.

 

[dh1633pm]

My M39 was .310 and shoots 308’s nicely. My Hungarian doesn’t shoot them as well. It was .312.

 

[GHinNH]

I've been exploring the possibility of adding a PSL 54 to my collection, as well as the things required to reload using a FMJ projectile. Seems I might be pretty much set up since I load 7.62x51. I was not real sure about bullet diameter after reading the Wikpedia segment about the cartridge, and the reloading data I've seen all says .308 diameter.

 

[AJC1]

I've been exploring the possibility of adding a PSL 54 to my collection, as well as the things required to reload using a FMJ projectile. Seems I might be pretty much set up since I load 7.62x51. I was not real sure about bullet diameter after reading the Wikpedia segment about the cartridge, and the reloading data I've seen all says .308 diameter.

I shoot 7.7 jap and have the same struggle. You may have luck searching for 303 British bullets and molds.

 

[Hooda Thunkit]

I pulled several PPU bullets for another project, and measured the diameter.
Mean diameter was .3115.

I had a 91/30 that slugged .315, and shot .316 cast from it.
I have some Finn M39 rifles that all slug .3105. I shoot .311 or .312 cast from them.

 

[GHinNH]

I shoot 7.7 jap and have the same struggle. You may have luck searching for 303 British bullets and molds.

Thanks, I do recall reading that somewhere.

 

[mdi]

K.I..S.S. You can read all the descriptions of the type gun you own, but you will never know what your barrel measures unless you measure it yourself. My MN slugs out to .312" which is not surprising because the rifle has been manufactured for many years and was made during war and peace so they will vary. There is a lot written about barrel slugging, videos on barrel slugging and kits available but the hardest part is properly using micrometers. If you are not up to the task, and you are serious about using the "perfect" size bullet, you can take it to a gunsmith. But unless you are all thumbs and have no tools, it is a very easy job and hard to screw up...

 

[walterelm]

If you have a russian / sowjet mosin he will most likely prefer .311 bullets. If it is a mosin from finnland it will need .308 bullets.