7.62x39 Question

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Ovenpaa
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Re: 7.62x39 Question

#11 Post by Ovenpaa »

the Gordy rods are fine however they do require a reasonably well set up machine to start with. Here is a good test, take a 20" length of bar stock. centre drill one end and lock it in place between the chuck and the tail stock centre. Now take a cut for the full length, take a couple if needed. Now measure the diameter at both ends of the cut. How much does it vary by? This will give you an idea of how far out of line our tail stock is, or if your headstock is canted if it is separate to the bed. This error/taper is going to be on most machines, even CNC. The only thing is you can tell the CNC what the error/taper is and cancel it out. There will be an error, in fact if there is no error why buy a floating reamer holder (OK, ignore that!)

I thought the viper was just a multi-point spider that clamps into a 4 Jaw? I see absolutely no point in it personally. I either use a low profile 4 jaw Pratt Burnerd chuck and spider at the drive end, or my own D1-3 Spider/Cathead and a drive end spider.

My reasoning is as follows:

A Barrel, in a spider in a 4 jaw can lead to quite a mass whirling around, especially when it is an off-set mass (Out of balance) Supporting it all outboard of the chuck is poor practice in my opinion. This is why I use the spider I have posted pictures of in the past, it is locked in place instead of being dependant on someone not under or over tightening something, or trying to perform a task at the wrong speed/feed.

Building your own is the easiest way forward. I have all of the drawings in the workshop if you would like a copy, I may even have something on this forum. The advantage of doing it this way is only one set of clocking in. The spider/cathead is already concentric to the lathe bore so that is one less operation to consider. The cost of making one is way less than buying something in and probably of a better quality. I routinely use mine for re-machining bolt faces and adding bushings for myself and for trade customers and I have to say it is remarkably easy to set up.
Cathead.jpg
/d

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Alpha1
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Re: 7.62x39 Question

#12 Post by Alpha1 »

I guess I will have to purchase a keyless chuck for my tailstock to use the Grizzly rod.

This is the viper I am referring to.
It is used with a four jaw.
3-in-1-chambering-fixture-jig-viper-international.jpg
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Ovenpaa
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Re: 7.62x39 Question

#13 Post by Ovenpaa »

I am not a fan for the reasons I listed before.
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Re: 7.62x39 Question

#14 Post by Alpha1 »

A pleasant surprise the barrel is held on with a barrel nut.
I have been reading up there was a 16" barrel version of the AIA in 7.62x39. Ruger also makes a bolt action version with a 20" barrel but its .308.
I am wondering if a 16" barrel in .308 would work. I am not clued up enough to be able to answer the question so some advice would be appreciated. Mine is a 20" barrel with 1 in 8 twist.
It's unlikely it would be used over 200 yards max and ideally with cast bullets.
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Re: 7.62x39 Question

#15 Post by Ovenpaa »

My experience is full fat un-moderated .308 barrels at less than 18" are very spiteful, however if you were simply lobbing cast out to 200 at sensible MV's it would probably be great fun. Also, with a 1:8 you could run some heavy subsonic rounds to great effect.
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Re: 7.62x39 Question

#16 Post by Alpha1 »

So it sounds like 18" would be a good starting point.
A correction the original barrel is approx. 1 in 8 twist. The new barrel would be a bog standard .308 barrel blank. I am only intending to use cast bullet loads. WHY because I all ready have the NOE Moulds and lots of resizing dies etc and loads of info how this gun works. Interestingly a article I read concluded as I did that one of the reasons these guns don't shoot very well is because of the front sight that is screwed onto the front of the barrel. I ditched the front sight early on in my ownership and fitted a scope the barrel is tapered and threaded I machined what in effect is muzzle break and binned the original front sight. If any one has any experience of working with or developing these guns I would appreciate your input.
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Re: 7.62x39 Question

#17 Post by mag41uk »

I have one of these rifles and have often thought about getting it rebarreled so I can use 308 bullets.
So much more choice of bullets.
I have seen the article by Thames Valley Guns about the conversion of one to 6.5 grendel.
But like you I have started to use cast out of it and it will knock down fig 11`s out to 300.
Not that there are many chances of doing so at the moment!
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Re: 7.62x39 Question

#18 Post by Alpha1 »

Mine will knock figure elevens down all day. My goal was to shoot it indoors at 25 yards accurately. I managed to do this the load development was done at an indoor range in Durham. Unfortunately, I am no longer a member of that Club the traveling was an issue. The loads were developed using fast pistol powders and cast bullets. Cast sized and lubed by my self. Unfortunately, my current club has an indoor and an outdoor 25-yard range but using fast pistol powders and cast bullets is forbidden. To be honest, since leaving the Durham club it's spent most of its life locked up in a cabinet. But I am fond of the old Girl so I am quite happy to take her out and clean her then put her back in the cabinet with her buddies.
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Re: 7.62x39 Question

#19 Post by Alpha1 »

I have also looked at the 300 blackout. I think that's based on a .308 bullet.
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Re: 7.62x39 Question

#20 Post by Alpha1 »

Does anyone shoot the 300 blackout? if so in what barrel length bolt action or semi-auto. If you had the choice of 7.62x39 or 300 blackout what would you go for. Bullet weights etc. You can move this to the reloading section if you feel it's the right place for it but I'm more interested in rechambering for my 7.62x39. I have reamers and gauges for both calibers.
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