re-barrel to 5.45x39
I would like to change a 7.62x39 bolt action to 5.45x39. Is the 5.45 a 20 caliber? Can I just call a barrel place like brownells? I think Steyer used to offer one back in the early 90s. Thanks for any input or help you can offer.
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5.45 is an undersize .22 centerfire, about a .221" bullet. PacNor makes their 5.45mm barrels at .222" groove diameter instead of US standard .224".
Its head size is smaller than 7.62x39, not the same case necked down. Depending on the action design, it might center up and engage the extractor and it might not. If not, bolt face and extractor reduction are harder than enlargement.
You are a proficient gunsmith and/or have a large budget for the job, right?0 -
I think nominally the 5.45x39 uses a .220 caliber bullet, but the military bullets will actually measure .220-.221".
Case rim is .394" which interestingly is almost identical to a .392" 9mm luger case rim.
Case rim of 7.62x39 is .447", and the overall cartridge shape is different.
I like the idea of a 5.45x39 bolt action too, but as Hawk Carse says I think that dimensionally, there is enough difference here that you probably won't be able to do this conversion from a 7.62x39 with just a drop in barrel change and you may have to work on the bolt face and/or extractor.
It well may be easier to start with a different caliber and open up the bolt face rather than go the other way around.
Getting a .220" bbl won't be trivial either. I don't think you're going to find this as a stock item anywhere.
You could use a standard .223 barrel, but unless you used standard .223 bullets you probably wouldn't see good enough accuracy to justify the trouble/expense of building the gun to begin with, and if you're already going to handload, you might as well just run .223.0 -
22sport,
Dimensions first:
Here is a CIP dimension diagram of the 5.45x39mm rifle cartridge developed for the AK74:
Since most folks don't bother with metric:
The bullet diameter is 0.2204" which I know doesn't mean much to the average Joe trying to put a rifle together to shoot cheap ammunition. What IS important is that you find a barrel maker who has those dimensions in use and isn't trying to make .22 cal. centerfire barrels work. Pac-Nor has them on their list as does Douglas Rifle Barrels. I can pretty much assure you that there aren't any 'pre-fit' barrels available for a bolt action rifle, that I'm aware of anyway. So you will need to go to the barrel maker or a gunsmith who has the reamers and numbers to work with for a good barrel.
I have several variations of the dimensions for the bullet diameter in my notes and the internet is full of misinformation and wrong dimensions. This is how S&W explains it with the release of their M&P-15R:
"S&W is using correct barrel dimensions for the 5.45x39 round with .217 (+/-.001) bores (the Russians mark it .215"-me) and .222 (+/-) groove diameters to ensure accuracy. There have been reports of 5.45 barrels using improper 5.56 dimensions for various other 5.45x39 chambered rifles, which is larger, with the expected adverse effect on accuracy."
As to making an existing bolt action rifle work with modifications, you will need to pay attention to the following depending on the model:
Bolt face alteration
Install new extractor
Adjust rails
Adjust feed ramp
Adjust magazine or magazine box
Adjust follower (possibly)
Thread, chamber and crown new barrel
Install new barrel, checking for proper headspace
There were quite a few SSG-82 rifles brought into the US a number of years ago. These were ostensibly made for the Germans as a sniper rifle. However, the extractor and trigger failures made it a fairly useless configuration.
While I understand the desire to consume cheap ammunition, that same cheap ammunition can lead to making an expensive project rifle. If you want to just blast away for fun, get a .223 Rem. If you want an accurate longer range rifle switch to the .22 PPC or the .22-250 Rem.
Best.0 -
Thanks Guys for the info. I bought a Rem. 799 mauser in 7.62x39 on here. I thought it was the same round necked down-then the bolt and other parts would all be the same, just change out a mauser barrel and it would be good to go. I should have talked to a gunsmith first. 0 -
I have built a bolt-gun in 5.45X39. Last year I bought a Savage edge when they first came out. I measured the bore and groove of a friends Romanian SAR2, and found them to be; .214 bore and a groove diameter of .222. The fine people at Krieger agreed to make a barrel for me with a 1/7" twist and the above dimensions. I chose there number 4 barrel contour and the 26 inch length.
I bought the chambering reamer from Pacific tool and got the GO/NOGO gauges from Clymer. I took it to my local gunsmith(about 40 miles away) and he fitted the barrel and altered the bolt-face.
The original magazine works great, but is a little tight. I wedged an old chisel between the lips and opened them slightly. I can get 5 round in, but it is a tight fit. I may try to develope a different system. I haven't mounted a scope yet, but I plan to this week. Hopefully will get out and shoot it some time this month...............0 -
Sounds like a substantial project.
What kind of ammo do you plan to shoot through a cu$tom Krieger?0 -
I am planning on using Wolf, Barnaul and the surplus stuff I bought a few years back.
I am planning on pulling the bullets on 500 rnds. and tumbling them in MOLY. I would like to see if I can get some kind of accuracy from the GI bullets. About the barrel; it has a 1/7" twist. The folks at Krieger were very helpful and there was no extra charge for the non-standard bore and groove diameter. The barrel has 8-groone rifling.................0 -
Start with a CZ 527, open the bolt face slightly and play with the magazine. Use your new barrel. 0 -
quote:Originally posted by 22sport
Thanks Guys for the info. I bought a Rem. 799 mauser in 7.62x39 on here. I thought it was the same round necked down-then the bolt and other parts would all be the same, just change out a mauser barrel and it would be good to go. I should have talked to a gunsmith first.
If you neck a 7.62x39 down to .22 you have a .220 Russian, not to be confused with the much later 5.45. I read in 1970 about one of the few Sako .220 R that made it to the USA. If you blow out a .220 Russian to a straight wall and steep shoulder, you get a .22 PPC, one of the best benchrest rounds going.
So you can make your rifle a .22 with only a new barrel, it just won't be a 5.45x39. Ammo will be expensive to buy or a good handloading project.0 -
Good luck with your project. I hope it turns out well for you. In passing I thought I might mention something about the accuracy I was able to achieve with the 5.45 in a Romanian AK74. These were the versions imported 10 or 11 years ago and had a base on the side of the reciever for a scope and so I got one and mounted it.
I started by weighing the individual rounds of ammo and segregating them accordingly. I used Wolf and Barnaul at the time. The heaviest rounds produced the best groups and I was able to keep 4shots of 5 in 7/8" of an inch at 100 yds. This seemed like pretty amazing accuracy for an AK battle rifle with a 4X scope at that range.
Since that time I had been thinking seriously about a bolt-gun to shoot this ammo. Will post more when I get some results......0
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