Ruger 7.62 x39mm Ranch Rifle .308 or .310 bore?

[Shooter6br]

Probably addressed before. I assume the bore is .310? i shoot cast in SKS with .312 Lee TL 160 grain. Twist is 1 to 10 in Ruger and SKS, Thanks ( May be trading time soon) :mrgreen:

[Larry Gibson]

Early ones had .308 groove diameter

[map55b]

I believe it is a .308, but can not sate for sure. I have a rifle I built in 7.62x39 with a .308 bore and it works just fine. I know the reamer I have from PTG has a long lead to accommodate for this and shoot anything from ~.312 to .308 without issue.

[Jeff Michel]

I have a recent vintage, .310 bore.

[gnostic]

I have a 189 series that shoots .312 cast bullets perfectly...

[Outpost75]

Early production Mini Thirtys used moderately oversized .30 cal. barrels which didn't gage up for regular production, in which groove diameter exceeded .3085". Later on I don't know. I do know that during the development and test stage they had pressure barrels made to both Lake City and CIP prints with both .308 and .310 groove diameters and shot all of the common ammunition available at that time. I provided some Vietnam-era Lake City, Chinese, and Russian ammo for them at the time, and they also shot Sako, Norma, Lapua and PPU.

While the .308 groove diameter raised pressure somewhat there was a greater difference between the Lake City (back-engineered from Chinese) and CIP chamber (similar to Finnish military, Lapua, Norma and Sako commercial), than there was between barrel groove diameters. The SAAMI chamber eventually adopted was based on the CIP chamber, with minor changes to reflect US dimension and tolerancing conventions, which gives pressures well within the Mini-14 design limits with all common Type PS and lead core ball ammo.

The Lake City and Chinese chambers provide less base support to the bullet than the CIP or SAAMI type chambers, and tended to raise pressure with flat-based, lead-core ammunition. While this was not an issue with GMCS mild steel-core PS ammunition in the LC or Chinese chamber, Ruger and SAAMI very wisely opted to base the chamber configuration adopted by SAAMI on the commercial version already in sporting use in the EU and adopted by CIP.

[Catshooter]

Notwithstanding all those excellent replies above, if you want to know any given bore size, regardless of what any manufacturer says, you must measure it yourself. This applies to any rifled firearm.


Cat

[marlin39a]

I have a new production mini 30 tactical. .310 bore. Ruger just announced the American Ranch in 7.62x39. .310 as well.

[Jeff Michel]

Ruger just announced the American Ranch in 7.62x39. .310 as well.[/QUOTE]

Swell, just when I make up my mind I didn't need anymore rifles.

[marlin39a]

Ruger just announced the American Ranch in 7.62x39. .310 as well.

Swell, just when I make up my mind I didn't need anymore rifles.[/QUOTE]

And it will take mini 30 magazines.