slugged my new 7.62 x 54

[aprayinbear]

What Gives?

I just slugged my new mosin-nagant and was surprised with the outcome. The bore diameter was approx. .299-.300. The grove measurement was approx .309-.310. I'm giving an approx. measure because it's hard to perfectly place the caliper for each measure. From what I have heard the grove size on my 91/30 is pretty small. (which makes me happy because I'd like to use a classic lee loader which is set up for .308 bullets.)

Is this unusual? I'd like to shoot cast bullets and was hoping that the .308 would work well.

I'm kind of flying by the seat of my pants here, but can't see that I've done anything wrong.

Thoughts? Suggestions?

Happy Shooting!

[NuJudge]

My experience has been that Mosin barrels run larger than that, all except those reworked by the Finns. By the way, are there any "SA" in a box stamps on it anywhere?

Check your micrometer against a known quantity, such as a .308" bullet, then load up some ammo and see what it will do.

[aprayinbear]

Nujudge,

Good advice. I did go by the gunshop today and took the lead I had slugged in my rifle. The guy was nice enought to double check with his caliper. He came out with .311-.312. That seems more in line. Sounds like my cheapy digital caliper might be off. I'll double check as you revised, but sounds like I need a better caliper .

All The Best!

[dhtaxi]

.311 .312 Is about right for a Nagant