Thread: Optimal or most balanced barrel length for 7.62x39mm

I've searched on here but can't see much info. Who's run one short?? How short??? What do the computer models say??? For close range bush gun that will be carried lots and shots be close,I've already got a short 222 in same rifle so know it will be great to carry and shoot but just it cautious with the different cartridge....

Have a look at https://rifleshooter.com/2016/01/7-6...h-on-velocity/
Velocity seems to peak at a 23 inch length barrel.

Interesting read thankyou....seems the reports/ suggestions to cut it short as won't be loosing a huge amount have merit..it's never going to be fast,it will just be a little less fast if made short lol.

18" is good, helps make it a handy rifle. Still getting a good velocity too. Howa minis come in 18". I also have a SMLE converted to 7.62x39, 18"

Looking at the US gun forums, they seem to think you can go down to 12" before the velocity really drops off a cliff.

It's a bit hard to find info as the Yanks are mostly using them in semi autos so have to deal with cycling issues, but somewhere around 12-16" seems to be the sweet spot.
Which is pretty much the same as a 300BLK which you'd expect being similar sized cartridges.

I'd just choose the suppressor you want to use and let that dictate the decision, based on over barrel length, forend length, etc.

Originally Posted by Beetroot

Looking at the US gun forums, they seem to think you can go down to 12" before the velocity really drops off a cliff.

It's a bit hard to find info as the Yanks are mostly using them in semi autos so have to deal with cycling issues, but somewhere around 12-16" seems to be the sweet spot.
Which is pretty much the same as a 300BLK which you'd expect being similar sized cartridges.

I'd just choose the suppressor you want to use and let that dictate the decision, based on over barrel length, forend length, etc.

Yes that is what dictated where I got to threaded....but then the light ulb moment and set of 30 cal baffles came up for trade.it can wear and share muzzle forward DPT with 222. So I can take it back to just Infront of sling attachment.

after cut

before chop

I'm hoping to pick up a 7.62x39 pretty soon, so that's why I've been looking into it.

I'm wanting a bush gun that'll shot subsonics, so really no downside to going as short as possible.

I don't like chopping the forend off a stock, so anywhere in the 12-16" range would be fine. Especially if you went the stubby length DPT (4" ish).

I think 14.5 was is as short as I would like to go, like my 7.62 AR. but lit looks like youv'e cut it to 16"? I looking for a Left Hand Mini Mauser in 7.62 (Bruno, Interarms etc). Rare? Yes, arround? yes...

@Micky Duck

You have a hacksaw
You have an engineers vice
You have a case mouth reamer
You have a chronograph
You can apply some science and look at the velocity trend
You may be smart enough to stop at about the right length

Then get your LGS to tidy up the muzzle and trow a tread on it

Originally Posted by akaroa1

@Micky Duck

You have a hacksaw
You have an engineers vice
You have a case mouth reamer
You have a chronograph
You can apply some science and look at the velocity trend
You may be smart enough to stop at about the right length

Then get your LGS to tidy up the muzzle and trow a tread on it

Oh forgot to mention, you might want to cross check against minimum legal length.

Originally Posted by akaroa1

@Micky Duck

You have a hacksaw
You have an engineers vice
You have a case mouth reamer
You have a chronograph
You can apply some science and look at the velocity trend
You may be smart enough to stop at about the right length

Then get your LGS to tidy up the muzzle and trow a tread on it

I have used a Lee case length trimmer to do a muzzle crown before - works a treat!

Originally Posted by Crusty

I have used a Lee case length trimmer to do a muzzle crown before - works a treat!

I'm not sure i should have out the idea into MDs head
It might appear to be a bit of a joke
But I always enjoy seeing things where guys do this with rifles and pistols and test their theories for real

From memory the trebly still about 800mm so plenty heaps legal.... Our man in Timaru did such a good job of threading this one at longest length so I could fit suppressor I had,I feel a bit daft now getting him to do it shorter....oh well isn't the first time n won't be the last time I do something daft lol.