7.62x39 in a .308 bore

[hoz53]

Im just wondering if anybody here has shot the import 7.62x39 ammo with the larger bullets(.311?) in a rifle with a .308 bore and how it worked. i was thinking of a savage or rem 700. i know the mini 30 was made with the 308 bore and i bet alot of 311 ammo has been shot in them. Thanks

 

[rockrat]

Yep, cut off and rechambered a 308win varmint barrel to x39 and stuck it on a savage action. Shoots about 1.5" groups @100yds with import ammo. Used the 308 bf and I do get a failure to extract about 1 in 10 rounds. Close the bolt again and try again and it comes right out. My Lapua ball ammo extracts every time and shoots a bit tighter groups if I do my part.

 

[riflewoman]

If the rifle was chambered for the bigger bullet (most are) the rifle shoots just fine. The Colt uppers for the 7.62x39 were made with 308 barrels. RCBS sell their dies with expanders for each bullet size.

 

[hoz53]

Yep, cut off and rechambered a 308win varmint barrel to x39 and stuck it on a savage action. Shoots about 1.5" groups @100yds with import ammo. Used the 308 bf and I do get a failure to extract about 1 in 10 rounds. Close the bolt again and try again and it comes right out. My Lapua ball ammo extracts every time and shoots a bit tighter groups if I do my part.

thats real good info. i was going to rework my bolt face but i think ill do like you say and try it now. Thanks

 

[hoz53]

If the rifle was chambered for the bigger bullet (most are) the rifle shoots just fine. The Colt uppers for the 7.62x39 were made with 308 barrels. RCBS sell their dies with expanders for each bullet size.

this is real good info to. ill make sure my reamer will be sized so i can use the import ammo. Thanks

 

[kevinbritvec]

Hornady bullets are actually .310" in diameter. You can reload using standard .308 bullets if that's what your bore measures. I believe Ruger Mini-30 chambers are designed to squeeze .311" bullets gradually smaller as they enter the bore.

.003" difference is actually quite a bit and a maximum powder charge might get you in trouble. It's not unusual or unsafe to load bullets .001" larger than actual bore dimensions. Pushing a .311" through a .308" bore is going to spike pressures. How much will depend on how hot the load is to begin with.

Most SKS and AK rifles made overseas can have bores measuring .312". I use Sierra's excellent Pro-Hunter 125 grain .311" bullets when I reload 7.62x39mm. 24.5 grains of H4198 or 28.0 grains of H322, IMI or PMC brass, Remington std. 9.5 large rifle primers and an OAL of 2.190".

These loads were gleaned from an old American Rifleman article and have worked so well for me I never experimented any further. Very few people bother to load this round because surplus ammo is so cheap. Quality reloads actually improve the accuracy quite a bit. My 7.62x39mm AR upper shoots 1.5" to 2" groups with ease with my hand loads, something foreign ball ammo can't even approach.

 

[hoz53]

Hornady bullets are actually .310" in diameter. You can reload using standard .308 bullets if that's what your bore measures. I believe Ruger Mini-30 chambers are designed to squeeze .311" bullets gradually smaller as they enter the bore.

.003" difference is actually quite a bit and a maximum powder charge might get you in trouble. It's not unusual or unsafe to load bullets .001" larger than actual bore dimensions. Pushing a .311" through a .308" bore is going to spike pressures. How much will depend on how hot the load is to begin with.

Most SKS and AK rifles made overseas can have bores measuring .312". I use Sierra's excellent Pro-Hunter 125 grain .311" bullets when I reload 7.62x39mm. 24.5 grains of H4198 or 28.0 grains of H322, IMI or PMC brass, Remington std. 9.5 large rifle primers and an OAL of 2.190".

These loads were gleaned from an old American Rifleman article and have worked so well for me I never experimented any further. Very few people bother to load this round because surplus ammo is so cheap. Quality reloads actually improve the accuracy quite a bit. My 7.62x39mm AR upper shoots 1.5" to 2" groups with ease with my hand loads, something foreign ball ammo can't even approach.

i guess you live close to me. Thanks for all that great info. i guess i will slug the barrel i have next to see wat ive got. i definately plan oan reloading some for this rifle.

 

[Twicepop]

Which import ammo, the stuff with bi-metal bullets? These are steel jackets with a flash-coat of copper over that, and will probably eat your barrel up in a record amount of time. I read an AR and ammunition longevity test a while back, with 4 guns in the test. The test had to be stopped mid-point and two of the guns replaced because they were using the bi-metal bullets and their barrels had been totally destroyed. The other two guns of the original four had none of the erosion the two cast out rifles had.

 

[hoz53]

Which import ammo, the stuff with bi-metal bullets? These are steel jackets with a flash-coat of copper over that, and will probably eat your barrel up in a record amount of time. I read an AR and ammunition longevity test a while back, with 4 guns in the test. The test had to be stopped mid-point and two of the guns replaced because they were using the bi-metal bullets and their barrels had been totally destroyed. The other two guns of the original four had none of the erosion the two cast out rifles had.

well i wasnt sure which import ammo. were all these rifles shooting the bimetal bullets? thats sure something to think about. was the bore of these guns 308? that ammo must shoot in some kind of barrel without destroying it. i may well decide to use this barrel i have in mind with a different caliber. Thanks

 

[jonbearman]

I haven't seen any of the copper washed garbage on the market in a while but you can get regular cup and core(lead) ammo easily in the surplus market. Too add to reloading I too use the sierra 125 grain pro hunter bullets at .311 diameter in a .310 bore barrel and the accuracy is beyond outstanding. Most of the modern surplus really isn't surplus as they are made with hollow points and soft points for hunting. The accuracy isn't anything to write home to mom about. They claim it isn't corrosive either but I don't buy what they say at all. I stick to reloads 100 percent in a decent barrel.

 

[hoz53]

good info Thanks Jon

 

[Frank Ambruso]

Best ammo is Yugo m67 copper lead bullet and brass cased.

Shoot this in my kreiger 308 barrel 7.62x39 lapua chambered k98 modded for single stack AK mags

Handloads are 135 and 155 SMK 29 GRS OF AA2230 bullet seated out

 

[hoz53]

Best ammo is Yugo m67 copper lead bullet and brass cased.

Shoot this in my kreiger 308 barrel 7.62x39 lapua chambered k98 modded for single stack AK mags

Handloads are 135 and 155 SMK 29 GRS OF AA2230 bullet seated out

that sounds like a cool deal -- a 98 that takes AK mags. is that a custom deal or does someone sell that bottom metal? seems would be for R700.
thanks for the ammo advice.

 

[people]

I made a rolling block in 7.62X39 with a 308 bore a long time ago. I just told the reamer maker I was going to use a 308 bore so make the reamer so it will cut smooth. I never had any problem shooting any surplus ammo in it even the stuff with the steel core. I never had AP but the steel core fired fine.

I did load up some steel core bullets from LPS and with proper load development it was fine. I did blow a few primers trying to make it something it was not.

If I were to make a 700 like what you are thinking I would still go with a 308 bore. When you buy factory ammo just buy the copper bullets. You can also have the barrel nitride finished. The reason I would go with 308 is you have so many more options in bullets in reloading than .311 bullets. With good bullets the 39 can be very accurate.

 

[hoz53]

I made a rolling block in 7.62X39 with a 308 bore a long time ago. I just told the reamer maker I was going to use a 308 bore so make the reamer so it will cut smooth. I never had any problem shooting any surplus ammo in it even the stuff with the steel core. I never had AP but the steel core fired fine.

I did load up some steel core bullets from LPS and with proper load development it was fine. I did blow a few primers trying to make it something it was not.

If I were to make a 700 like what you are thinking I would still go with a 308 bore. When you buy factory ammo just buy the copper bullets. You can also have the barrel nitride finished. The reason I would go with 308 is you have so many more options in bullets in reloading than .311 bullets. With good bullets the 39 can be very accurate.

i think youre right about the .308 bore. I will just talk to the reamer maker and see wat he suggests. thanks for all the info

 

[Frank Ambruso]

I had kendog4570 on calguns.com forum make me 6 rifles now, he has 7.62x39mm lapua reamers.

He has made rem700 mods in this caliber.
Just finished a 1898 smokeless roller for me in 30-30 Gates (Elgin, tight body base) with takeoff .308 palma 13" twist barrel

 

[Frank Ambruso]

7.62x39 lapua reamer is throated for cast bullets and heavy JACKETED 308 bullets (135/155 SMKS) shoot extremely well.

M67 Yugo and similar combloc ammo bullets shoot fine with no pressure signs.

Original combloc .309/.310 bullets have small bearing surface and do not impact high pressure spikes being oversize in .308 bore.

 

[Frank Ambruso]

Another AR option is to buy 300 blackout and run a7.62x39 lapua reamer in.

Kendog4570 did that for me on a wilson 18.5 SSTL barrel.

 

[hoz53]

Another AR option is to buy 300 blackout and run a7.62x39 lapua reamer in.

Kendog4570 did that for me on a wilson 18.5 SSTL barrel.

good info Frank Thanks much.

 

[Lone Hunter]

good info Frank Thanks much.

hoz53, here are some decent prices on some bullets for the x39 just in case you didn't want to go .308. Plus they have some good prices on some .308 bullets also.
http://www.shootersproshop.com/nosl...3/9/18&utm_campaign=3/9/2018&utm_medium=email