7.62x45 rechamber?

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May 26, 2013
Meridian Idaho
Well I just bid on a local online auction for a VZ52 7.62x45 semiauto rifle, I've been doing a bit of googling, and have found that the x45 round is all but impossible to find, and that on rare occasion, one can find a x39 chamber adaptor, or shorten the barrel and run a x39 reamer, along with a touch of other machining, like adding a pin groove, etc. But my question is this, could the barrel be rechambered for a bigger .30 caliber round? Like more specifically I was thinking 7.62x51/.308? I considered that the bolt may not travel far enough to cycle the round, but googling has gotten me nowhere as far as overall length of a x45 round, also couldn't find a pic comparing x45 to x51... I found a few pics comparing x39 to x45 and they look visually very close in length. If the bolt would travel far enough to cycle the .308, I could definitely accomplish the required machining, like chamber reaming and bolt face widening if needed. So any feedback on the overall length of the 7.62x45 round would be greatly appreciated, also the rim diameter if someone can tell me? Thanks!

If the .308 is a definite impossibility, could it be rebarreled to accommodate another (shorter) common US hunting round? Like maybe 6.8spc? Or other AR length rounds like .223 or .300blk?
The VZ52 is similar to an SKS. It really can't handle heavier calibers. The later VZ52's, the VZ52/57s, were modified for 7.62x39 before being replaced almost immediately with the VZ58.
You might look @ .300" Blackout. It's 7.62x35mm. What's the bbl dia? Perhaps you can set the bbl back by 6mm? 7.62x39's definitely the cheapest route to go.
It's highly unlikely the action and/or magazine would be suitable for 7.62x51.
Using a chamber insert to 7.62x39 is likewise improbable since there's not that much difference in case diameter/length. The rim diameter is the same as the 7.62x39 but the x45 has slightly larger base diameter and of course, is longer. The only viable recourse would be setting the barrel back and rechambering.
The 300 AAC is a totally different case diameter/shape and the low gas volume would make function problematic.
Ok thanks for the fast response! I was afraid of that, I figured that there might be problems cycling .300blk, and converting to 7.62x39 seems relatively well documented and minimal work. Just shorten the barrel from the breech end, turn it to fit in the action, and ream for x39, then add the groove for it's locking pin. And then there's the fact that x39 is 100 times more common than blackout, at least for now. I'll have to keep an eye on the bidding, It'll make a nice addition to my collection to sit next to my pretty, all numbers matching SKS paratrooper. Thanks again for the fast responses!
The 7.62 Soviet bore has .311-.312" grooves. The 7.62 NATO bore has .308" grooves.
However, after hearing from multiple handloaders who reload for the Mosin Nagant for accuracy, it usually isn't enough to make a difference. .308 bullets normally shoot just fine out of a .311 bore with no loss of accuracy. Unless the barrel is very worn, it won't really matter.
According to my copy of "Cartridges of the World", the 7.62x45 uses .309 bullets. I have no reference which gives the bore/groove diameter of the specific rifle mentioned.
You can buy dies and brass for the x45. They are pricey though. I used to have one. You could still buy ammo then though. You occasionally can find surplus ammo for $1per round.
Hm... So slugging the barrel will probably be the best place to start, so I can verify the diameter of the bore/grooves. I'm buying the rifle site-unseen so the barrel might be so rusted or shot-out I may need to go with a new 7.62x39 blank regardless. Thanks for that info. .309 is 1/4 a hairs thickness bigger than .308, and .002 less than the groove diameter of .311 of a x39 barrel... Maybe I will mic some of my x39 ammo stock when I get home tonight, just to see what it is exactly...
Just looked it up and x39 (according to Wikipedia, so consider the grain of salt) mics at 7.92mm or .312" but every barrel blank I've seen for the x39 is spec'd .311" dia at the grooves... Makes sense I guess as it means each shot theoretically stretches the barrel, creating the gas seal... But does that mean that the x45 uses a .308 groove dia?
I remember looking at those in '00, CAI was gluing?? A chamber insert so you could shoot x39. Like most of their work, it wasn't well done. How did others do the insert? That's the trick to make it work. That and fixing the cracked stock, they ALL had that.
Yes, and if you don't notice that, the next round will be a 7.62x51/.308 fired in a 30-06 chamber. It won't blow the gun up, but it certainly will destroy the brass and it won't do the chamber any favors. Extracting the blown case can be a pain. On the range, it will be a big irritation. Should you be hunting or using for self defense.....
Wow, what a cool gun! I'll have to admit, if I landed one of those I'd have to do whatever it took to get my hands on dies and a supply of brass to load the original round.

There's no way I could hack one to shoot some other cartridge. I know that's a tall order, but quite possibly still money ahead, by the time you'd finish converting it.
Yes, except for the small detail of what I do for a living, which allows me access to machining/toolmaker equipment at $0 cost... Shortening a barrel and reaming a chamber will cost me all of about 2 hours of my time. (About $80 if I compared it to the equal amount of overtime, which, I'm not getting any overtime allowed anyway) and for the pennies I'm paying for the barreled action, bubba'ing this thing will bring me quite a bit of joy.
I have had one of these rifles for years. Really neat design. I bought 500 rounds of surplus ammo and 100 rounds of reloadable brass but have not shot it yet. The surplus ammo is corrosive and the gas system looks to be a bear to clean thoroughly.
I considered setting the barrel back and rechambering for x39 but the rifle is so nice I decided to leave it as is.
I will dig the surplus ammo out and measure the bullet diameter for you.
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