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7.62x39 Question

Posted: Sat Aug 22, 2020 11:48 pm
by Alpha1
I have an AIA (Australian International Arms) rifle I have had for a lifetime. It shoots great with cast boolits now that I have worked out a cast boolit recipe that works. I had to have a mould cut by NOE to get it to perform. But that's another story.
I have had some success with jacketed bullets but the cast boolits work better.
As I said earlier the muzzle looks like a moon crater.
The bore is at least .311 if I stick a .308 grizzly range rod with a .311 bushing will that work for dialing it in.

Another question if I use a long dial indicator won't it pick up the lands so you will get a low then a high reading are am I missing something.

Re: 7.62x39 Question

Posted: Sun Aug 23, 2020 12:00 am
by bradaz11
no help to the question, but is the gun one of the no.4 rifles in 7.62x39 with the detacheable ak mags?

Re: 7.62x39 Question

Posted: Sun Aug 23, 2020 12:44 am
by Alpha1
bradaz11 wrote:no help to the question, but is the gun one of the no.4 rifles in 7.62x39 with the detacheable ak mags?
Yes it is.
I have to say I have had a lot of fun with this rifle. I really like it. The muzzle, in my opinion, is why they don't shoot very well normally.
The front sight is screwed on and accumulates a lot of debris.
I am fond of this rifle and determine to get the full potential from it.
I have been scouring the internet to find the tools to be able to make this gun work to its full potential.
Acquiring the tooling has probably cost me three times what the gun is worth.
I would actualy like to re barrel it. The issue is the 7.62 chambering is deceptive they are rarelly chambered in .308 they are normally around .311.

I could easily chamber it in .308 but I would rather not.
Any way just another project.

Re: 7.62x39 Question

Posted: Sun Aug 23, 2020 2:12 am
by bradaz11
bloke of bloke on the range youtube channel fame really seems to like his, and a gun i've always fancied as it's a little bit different.

as for the bullet, well it's the same as 7.62x54r which is essentially a 303 bullet isn't it? it's just a different measurement naming convention. I think it would be a shame to rebarrel it, you may as well get a 2a1 or an envoy, rather than change that to something else again.

Re: 7.62x39 Question

Posted: Sun Aug 23, 2020 8:18 am
by snayperskaya
bradaz11 wrote:bloke of bloke on the range youtube channel fame really seems to like his, and a gun i've always fancied as it's a little bit different.

as for the bullet, well it's the same as 7.62x54r which is essentially a 303 bullet isn't it?
7.62x39 uses .310" bullets....

Re: 7.62x39 Question

Posted: Sun Aug 23, 2020 11:24 am
by Ovenpaa
Alpha1 wrote: The bore is at least .311 if I stick a .308 grizzly range rod with a .311 bushing will that work for dialing it in.
Yes.
Alpha1 wrote: Another question if I use a long dial indicator won't it pick up the lands so you will get a low then a high reading are am I missing something.
That is exactly what happens when you are clocking from the bore, you are looking for a consistent high point as it hits the lands.

Re: 7.62x39 Question

Posted: Sun Aug 23, 2020 11:27 am
by Ovenpaa
I forgot to add, you can always machine your own bushings. I machine mine from brass for exactly this job when needed, just do everything in one hit so the bore and outer diameter are concentric. I am looking at around 8 feet of 8mm OD brass bar which is also handy for assembly/dummy pins and soft faced punches for working on shotguns.

Re: 7.62x39 Question

Posted: Sun Aug 23, 2020 11:57 am
by Alpha1
Ovenpaa wrote:
Alpha1 wrote: The bore is at least .311 if I stick a .308 grizzly range rod with a .311 bushing will that work for dialing it in.
Yes.
Alpha1 wrote: Another question if I use a long dial indicator won't it pick up the lands so you will get a low then a high reading are am I missing something.
That is exactly what happens when you are clocking from the bore, you are looking for a consistent high point as it hits the lands.
Thanks.

Re: 7.62x39 Question

Posted: Sun Aug 23, 2020 11:59 am
by Alpha1
snayperskaya wrote:
bradaz11 wrote:bloke of bloke on the range youtube channel fame really seems to like his, and a gun i've always fancied as it's a little bit different.

as for the bullet, well it's the same as 7.62x54r which is essentially a 303 bullet isn't it?
7.62x39 uses .310" bullets....
I use a .312 Loverin cast bullet. If I use jacketed I use .303 bullets.

Re: 7.62x39 Question

Posted: Thu Sep 10, 2020 5:50 pm
by Alpha1
Hmm, I got it wrong again.
I understood that a Gordy Gritter range rod is about twice the length of a normal range rod but I assumed they would be tapered like a conventional range rod.
They are not they are the same outside diameter the full length of the rod. The size of the bushing that you fit on the end makes it a snug fit in the bore. Gordy holds the other end of the rod in the tailstock using a keyless chuck. I didn't realize this until after I had measured the rod and compared it to a conventional range rod. Curious I went back and reread the chapter on dialing in. I should have paid more attention in the first place.

I see what you mean about making your own bushing David (ovenpaa) now I have had a look at one in the flesh. Luckily I have a stash of brass rod so if I need to make another bushing I can.

While I am here does anyone have experience of using a Viper action truing/dialing in fixture do they actually work for dialing a barrel in? According to the blurb you can do everything from the chuck side of the lathe so you do not use a spider on the back end of the spindle. They are a shocking price to buy though you would have to be using it a lot to justify the cost.