Thread: Best 7.62x39 subsonic loads and tips

Originally Posted by Micky Duck

was with rifle when I bought it.....looking at it they have chopped bum off it and then spot welded base back on shortened box.

Chuck up a pic if you could please, I might lop one of mine off

an update, I was planning to chop my mag then re-weld together as I have a tig ect, but I came up with a far better option, I chopped it to almost flush, then I simply put it upside down in the vice with aprox 1mm protruding out the top of the vice, I then used a flat punch and carefully hammered the edge over it looks like a factory job, really happy, I have also bought me some trail boss and some 151gr lead projectiles from trademe and loaded them to 8.5grs, tomorrow I will test my new weapon, I look forward to it, fingers crossed the weather holds out.

Very neat idea with the mag. How many does it hold now? 3? Did you shorten the spring? I started having a tutu with one, but the follower got very "divey"

Yea I also shortened the spring, it only holds two in the mag, but one up the spout and two in the mag is fine with me, not often a second shot is needed let alone a third, its so much more comfortable to carry now, yes my follower was rather divey at first, but I have been playing a bit and have nearly got it right, it cycles fine currently but I am yet to do a final pull down and smooth of any rough factory edges.

I could possibly modify it more to hold 3, I could maybe cut the spring down a tad more or even look at a different spring all together, and then maybe do something with the follower to allow it to drop further down

Shortend the spring a tad more and had a bit of a play with the follower, now holds 3 rounds and cycles great, unfortunately raining here today so wont be able to test my first reloads

Perfect, well done

Those projectiles look brutal. How far does the hollow point go back?

the hollow measures at 2.5mm and tapers down to a point approximately 5mm down

Originally Posted by Max Headroom

Those projectiles look brutal. How far does the hollow point go back?

Here is one recovered from a goat shot at 40 metres velocity 1021FPS,
I size them .310" so they will work in .308 win and 7.62x39 the 39 bore diameter is .300" groove diameter is .310" the .308 win is .300 x .308"
cast bullets generally require .001" over groove diameter to seal properly, if you use Trail Boss powder it has the same burn rate and pressure curve
as Black Powder and gives the bullet a hefty boot in the base to obturate it into the rifling, Don't try loading much above 1100FPS in the 7.62x39
it will more than likely strip lead from the bullet and foul the barrel, So far no one has complained to me about getting any lead fouling with these bullets.

seat your bullet out further, as far as the magazine will allow

Thanks for the tip mate, im new to reloading and still yet to test them, could you please explain the benefits of seating the projectiles to the length of the mag vs seating the projectile lower, I also have some high velocity projectiles I plan on loading once I get this rifle sorted so all tips and info are welcome. Thanks

Originally Posted by KaneB

Thanks for the tip mate, im new to reloading and still yet to test them, could you please explain the benefits of seating the projectiles to the length of the mag vs seating the projectile lower, I also have some high velocity projectiles I plan on loading once I get this rifle sorted so all tips and info are welcome. Thanks

Driverman explained the case for seating bullets pretty damn well from the point of view of dealing with the specifics of 7.62x39.

Here's my 2 cents on the broader reasons for seating bullets mag length, or deeper.

Seating bullets mag length,ie as long as you can reasonably load them, is a safe bet from the point of view of pressure. The deeper you load them, the more pressure generated inside the case. There's a margin where seating them deeper isn't gonna be a problem particularly, so it's not as if it's a no-no.

The other problem is what's called a compressed load. This is where the bullet is seated so deep that it starts to scrunch up the powder in the case.
Sometimes it can be done, sometimes it's a bad idea. It ramps up the pressure inside the case .
ADI loading tables put a "C" beside compressed loads, eg 40.5C (40.5 grains of powder, compressed load)
Too much pressure, and things like primers popping out or being pierced, cases separating inside the rifle,and other unsettling stuff happens.

Trailboss doesn't like being compressed. It may not actually be dangerous ( debatable) but the performance of the loads is said to become erratic.

The other reason for seating at mag length is that the projectile is sitting in the chamber a little bit closer to the rifling than it would be otherwise.
Rifling is composed of lands and grooves.Think of this as being like a rut in a muddy field. The lands are the high edges of the rut , the grooves are the bottom of the rut.

Once it's fired, the lands grip the projectile and spin it, making it stable.

The notion ( as I understand it) is that the shorter the jump for the projectile from the neck of the case to the lands, the better.
I think it helps with bullet stability in flight.

Each rifle has a sweet spot for seating projectiles that it responds to best. Some people swear by seating projectiles long like this, some say that their rifle works better when they do the opposite.

The main thing is not to seat the projectile so deep that there's a kaboom, and your rifle turns into a cloud of flying parts.

There's more to it than this, but that's the short version.

It would be a good idea to google "rifle case overpressure signs" and look at pictures of loads that show danger signs. I generally look at my cases when I've fired them to see if there are any indicators.