Subsonic & Supersonic Load data for the 7.62x39 and 200-220gr. Jacketed bullets

[dthunter]

Hi there gunnutz!
Does anyone have any specific Loads for the 200Gr. Sierra btsp, and the 220Gr. Sirerra RN bullets in the 7.62x39?
I would like to get both full supersonic loads and subsonic.
I would like to try these bullets at 1000fps or so.
Any ideas?
Send me a personal message if you need to.
Thanks guys!!!

 

[2bad4u2]

Suputin is the guy you need to talk to on this. Subsonic 7.62x39mm is viable but not all that popular. You can check out his site on the topic here: http://members.shaw.ca/cronhelm/762Page.html

FWIW, neither of the bullets you listed will be ideal for .310"-.311" bore rifles. If you're looking for heavier bullets for this application, your choices are few and far between. Having said that, there's (1) particular bullet that may be a good option for you it's Lapua's 200gr. .310 D166 FMJBT Match. Hirsch Precision carries these and he's a good guy and a board sponsor.

Why not consider cast boolits? They're a perfect match for what you're looking to do.

 

[dthunter]

Hello 2bad4u:
Sorry that I never supplied enough info!
I am trying this combo with a ruger M77 Hawkeye (7.62X39)
I managed to try a Trail Boss and a Red Dot load last friday.
Both loads shot inside .75" at 50yards.
I was very pressed for time, so wasnt able to Chrony the loads.
Next time out, I will Chrony and shoot at 100yds.
I could not believe how deep the 220's penetrated the wood backstop at 50yds!
They penetrated approximately 12-14".
The wood blocks were laid down length wise.
I am shooting the Sierra 220gr. Round nose. .308 Diameter.

 

[2bad4u2]

Sounds as though you're on the right track. If I recall correctly, Ruger uses .308" bore diameter in its 7.62x39mm barrels as opposed to the normal .310" bore. It certainly is an advantage as far as bullet selection is concerned. Gives you far more flexibility and choice.

I'd be seriously inclined to try those 200 gr. Lapuas. I know Hirsch Precision has them in stock as I discussed it with Peter last week. These bullets were designed to work in 1:10" twist barrels so I think it would be a good experiment to try some.

If you search the right sites, there is some data on subsonic 7.62x39mm. "Silencer Talk" and "Silencer Research" are (2) of my favorites. You might even get some decent load data from "Subguns" as well. All of thos sites are .coms.

Peter's (Suputin) site is a great resource as well. I'd bookmark his site for future reference.

 

[Ganderite]

2400 is an excellent powder for your project. Start at 10 gr and work down from there.

 

[Juster]

If you are going subsonic with unpublished load data, firing in a rush with no chrony isn't ideal.

 

[Suputin]

The Lapua 200gr subsonic bullet is by far the best choice. It is stable where others aren't, it is more accurate than anything I ever tried and it won't get stuck in the bore like conventional bullets.

Read my Develop Subsonic web page for more info.

 

[ben hunchak]

If twist rate is marginal for any of the bullets you try, subsonic speeds will make any problem more apparent. My 1-13" barrel requires higher speeds for any kind of accuracy with any bullets around 200grains.

 

[Ganderite]

Your bullet should be as short as possible, as in Round Nose, Flat base. I have found 1:10 works at low velocity. have not tried it in 1:12.

 

[2bad4u2]

Your bullet should be as short as possible, as in Round Nose, Flat base. I have found 1:10 works at low velocity. have not tried it in 1:12.

I have tried in 1:12 in .308 Winchester. For me, it hasn't worked out. Your results may vary. It's not ideal in my opinion, even with lighter bullets. I had a nice low velocity load using 110gr. RN-FMJ .30 Cabine bullets, 9.5gr. Trail Boss, and WLR primers. Standard flash hole size.

When the round was fired, it sounded like high pressure steam in a pipe, then you heard the bullet hitting the target backing. I was shooting at 100 yds. At that distance, if the round was supersonic you'd just hear the muzzle blast and the ballistic crack of the bullet. You'd never be able to distinguish the sound of the bullet hitting the target backing. Unfortunately, it wasn't very accurate and resembled a shotgun pattern. I suspect a tighter 1:10 or 1:8 twist barrel would have tightened the groups up accordingly.

Further load development @ 11.5gr. Trail Boss yielded acceptable accuracy under the circumstances, however, it was not a subsonic load. I've put (15) shots at 2 moa at 100 yards. A nice plinking load that was easy on my ears, shoulder, and pocketbook.

I wouldn't waste my time with 1:12 twist .30 cal. barrels if it was my sole desire to shoot subsonic cartridges.