Just bought a near new Ruger 77 Mk1 stainless in 7.62x39. I had in mind to rebarrel and chamber for a 6.5 PPC but first I'd like to try it as is. Does anyone know if the ruger barrel is .308 and will therefore take any standard 30 projectile.
This rifle came with some handloads which I have dissassembled but I find some projectiles are 308 and others are 312.

don't know on the 77, but the mini 30 was 308

jeffe

IIRC the Rugers have 308 barrels but are chambered and throated to accept military .312 ammo without excessive pressure. That means it works the necks on the brass pretty hard. Most reloading dies are designed to size down enough for 308 and some come with two expander balls, some don't.

For the record, 308 projectiles shoot pretty well in the larger 312 bores so it really doesn't matter too much; other than there are so many more bullet choices in 308.

quote:

For the record, 308 projectiles shoot pretty well in the larger 312 bores so it really doesn't matter too much; other than there are so many more bullet choices in 308.

Although MAK-90's and SKSs aren't particularly known for their accuracy, I've fired a few handloads with .308 bullets through mine and find that they shoot pretty much like a .311 bullet. If I had the Ruger, I'd use .308's in it.

Slug it.

My info is that Ruger went to .310 long ago.

The 7.62x39 is a splendid cast bullet cartridge, btw.

I have one of these in Stainless with the boat paddle stock. It shoots Brown Bear ammo like it was match ammo!!! This is just what I have on hand and am very impressed with it!.
It doesn't show any signs of over pressure(hard bolt lift) etc, etc. seems to be normal in all respects. This rifle is exceptionally accurate for using FMJ russsian ammo. Must be swaging down the .311 bullets in the .308 barrel adds something to the accuracy!!!

I slugged the barrel of my 7.62x39 Model 77 when I got it, and found the diameter to be .3105".

This agrees with a statement made by Ruger some time back, that their 7.62s were built with .310" bores.

My rifle has now had about 1200 cast-bullet rounds through it, and NOT ONE jacketed round. I got it for the express purpose of serving as a cast-bullet test-bed, and to date I've used bullets from 130 grains up to 220. All gave some sort of reasonable accuracy, and some were very good, indeed. I usually size at .311", but have tried a few at .314".

No leading appeared with any load.

I installed a Timney trigger on mine, which is a considerable improvement. However, I did manage to get a pretty decent trigger with some work on the stock trigger, too.

Bad Ass, you can do a lot of interesting things with that rifle, but the 7.62 X 39 is way under rated on it's own. Especially with quality handloads. I hope to be doing some additional load developement in the next few days using Lilgun powder and 110 Hornady V-MAX's. So far they have given 2500 ft/sec's in a 16" Colt barrel. The 125's went 2250, and 155 Sierra's 1950 in the Colt. I have a Sako with a 21" 1 in 12 twist that is .308 diameter to try as well. The accuracy with the 155 Sierra's is amazing, 24.5 VV 130 Fed 210, and IMI brass. Less than 1/2 MOA. Enjoy your find.

My Wife's Ruger 77 MK2, a boat paddle Davidson's special run from 1992, appears to have a tappered throat and a .308" bore. It even shoots steel-case plinking ammo into acceptable groups.

Jeff

Paco Kelly has done some very interesting work with the 7.62x39 in a bolt-action rifle. He used to have articles at sixgunner.com but I can't find them now.


Okie John

Check this thread out

I have found that in a .310 bore there is NO measurable diffrence in accuracy between the two bullet diameters

I have one of the '92 era Ruger M77s in 7.62x39. It is a nice rifle and I enjoy it a lot. I always 'thought' it had a .308 groove/.300bore and seems like the literature that came with it said so.

Any way it shoots .308 bullets better than .310s or .311s but shoots the cheap stuff pretty well too. I did replace the mainspring with a stiffer Wolff one as I was getting some misfires with surplus Yugo ammo. It hasn't had a misfire since that replacement.

It is a great rifle in a fun, serviceable chambering. Plateau Hunter

Mine is mounted with a 3.5-10 Leupold and has been an outstanding shooter. Last time out with Lapua FMJ ammo it shot a perfect .4" triangle at 100 yards...it rarely shoots over an inch if I do my part. I have so much 7.62x39 ammo I have not had to reload for it...probably the only caliber gun that I don't...when you can buy accurate ammo cheaper than you can buy the bullets to reload with...what is the sense.

A friend in Texas has one...after dropping his first three deer with three shots he sold his long time .270 and never hunted with anything else...

Bob

My oldest son started on that exact rifle...does a nice job on deer at 120 yards....

A few years later he had moved up to the '06 and took this at 300 yards with a 168TSX....


I believe the 7.62x39 is an excellent way to start people off!

IV

quote:

Originally posted by jeffeosso:
don't know on the 77, but the mini 30 was 308

jeffe

Right. The Mini was a .308, with throating to swage down .310"-.311" bullets so various military ammo could be used in it.....


The 7.62X39 will shoot. This was fired with a CZ carbine...... .308 Sierra bullets.

Bad Ass Wallace, you may want to check out this site if you are going to rebarrel that 7.62x39...

www.65grendel.com

The 6.5 Grendel is the 6.5 PPC improved. Factory loads are available, and Wolf is adding it to their line this year. I have a CZ527 that was rebarrelled from 7.62x39 to 6.5 Grendel by Brockman's Rifles, and it is a joy to carry and shoot.