Light Lee 312-160TL 7.62x39 load

[Stoats]

Probably a duplicate thread, but anyway...

After having great success with this bullet and around 6.5gn of Ba10 (Bullseye equivalent) in .303 Brit, I want to replicate this load in 7,62x39 with the same powder.

What I'm looking for is a 7.62x39 load that is just subsonic (incidentally, 6.9gn Ba10 just goes supersonic in my .303"), around 1050-1100fps from an 18" bbl.

Ed Harris's sticky article, which recommends 6-7gns of fast powder in 303 & larger suggests, strangely, no more than 4gn in 7.62x39. This seems a little on the low side, seeing as other loads at higher velocities quoted seem to be just 12-15% lower.

Indeed, with the lighter 314-90gn bullet, loads from people on here run at around 3.2gns in 303 and 2.7gns in 7.62x39, around 15% lower.

Thus, one would imagine that with the 160gn bullet one should be using something in the region of 5.1-6.2gns of fast powder.

Does Ed know something I don't, or was his <4gn load only for 50 yds and less?

[Treeman]

I don't know what Ed knows in this regard-I also thought that his 4 grain ceiling seemed low since the case capacity would seem to safely accommodate heavier charges......1 thought that occurred to me was that he might be trying to keep the load light enough to not halfway operate the gun's gas system and thus create case damaging jams at every shot.

[Stoats]

Aah, that could be it, and would explain his reference to 50yds, since <4gn might not have enough legs for 100yds.

I'm shooting a bolt-action anyway, so I don't have gas systems to worry about.

I think I'll suck it and see and load 4, 4.5, 5, 5.5 and 6 and see if I get any pressure signs and at what point it goes supersonic.

[mag44uk]

Stoats,
Are you in the UK?
What gun are you loading for?
Tony

[Stoats]

No, in NL. Loading for AIA M10-A1. It'll be getting a .308 dia tube this summer so I'll be sizing the 312-160's down to .309 for it, but at the moment it's standard.

[mag44uk]

Keep in touch! I am just about to get one as per the other thread here that I started.
I thought the bores on these were already .308?
Have you slugged yours?

[Stoats]

Just done it - just under .303" lands, bang on .313" grooves.

That certainly explains the accuracy issues with them! Lucky I had some sized 314 bullets around to slug it with - the 312's wouldn't have touched the sides!

I suspect that these are actually Chinese RPK-47 barrel stock, because they are chromed and loose as a Colchester streetwalker.

[mag44uk]

OK thats interesting. That would account for their reputation for poor accuracy.
I should have mine,its secondhand,in about 3 weeks once I get my licence back.
I will let you know what this one slugs at.
I feel a challenge coming on!
You have been to Colchester then :)

[chrispy]

Remember that the 7.62 x 39 also has an almost identical case capacity to a 44 Rem mag. And load data I have found co relates pretty well to get your heavy projectiles moving. I have gone up to 190gn GC projjies in the Russian, with no issues and they putt along at about 900fps, using the load data for the 44 rem mag.

Mine is the AIA M10a2.

Chrispy

[mag44uk]

Nice info......keep it coming!
Tony