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Posted: 7/2/2026 7:32:58 PM EDT
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Wait what? Yep you read that right. This is going to be a long one, as I have been working on it off and on for about 6 months now. If you do not like reading, this is not for you. 7.62x54R gets a bad rap for not being accurate, but it is more so the guns and not the round itself. Most are worn out old milsurp rifles. Most also have between .310 and .312 bores. Match bullets in those diameters are very hard to find, and would kinda be a waste in a milsurp anyways. Shooting a .308 bullet out of those bores results in even poorer accuracy. I always thought a modern bolt action rifle in 7.62x54R would be pretty cool. There are a few modern semi auto SVD style rifles, but pretty much nothing out there on the modern commercial market for bolt actions. There are a few very hard to find models not available in the states, or very rare and hard to find here in the states (example, Izhmash record) I have been a fan of 7.62x54 for around 25 years, have several mosin nagants, and handload for it. I decided instead of trying to rebuild/rebarrel a mosin nagant, I would start with a modern rifle/action and try and adapt it to the round. I wanted something common and easy to find, easy to work on, find parts for, and if I totally fuck it up, it is not that big of a deal, as it is nothing collectable. Well I knew right away the perfect candidate. The Savage 110 series. Easy to swap barrels, easy to change the bolt heads for different calibers, parts are easy to get and there is aftermarket support for them. Now to find the right one to start with. 7.62x54r is too long for a short action, but a little short for a long action. So I figured a long action was best, as it would be easier to make work. 7.62x54r had a rim diameter of .570, well, because it is rimmed. So was there a bolt head for the savage that was close to the same size? 300 win mag has a .532 rim diameter, so very close, and it is a very common round, so rifles would be easy to find. There was also 338 Lapua, with a rim diameter of .588, so a little bigger. So before I bought a rifle, I decided to just order a bolt head to see if I could make it fit. So I decided to try a 300 win mag bolt head first. I order one online and chuck it up in my lathe and open it up till it fits 7.62x54r. Just a little work to the extractor and it fits/works too. So the savage bolt head is recessed a little. The one I got measured .116 deep. Because of the design of the extractor, it really can not be any shallower. So what about headspacing? 7.62x54r headspaces off the rim, not the shoulder like other bottleneck cases do. Using the savage bolt head, some of the case head will be unsupported. Well lets look at a mosin nagant. The rim sets flat on the breech of the barrel, and there is a cut out for the extractor. There is part of the case head exposed at this cut out. Here is a picture of a round in a mosin nagant barrel.  So if I measure from the breech face to the bottom of that groove, it is .040. So there is that much of the case head unsupported. But, there is also headspace. 7.62x54r go gauge is .065, so from the breech face to the bolt head can be that much of a gap. So .040 plus .065 is .105. No go gauge is .070. However there is also something called a "field" gauge, that if it closes on a no go gauge, but will not close on the field gauge, then it is considered still ok to shoot. The field gauge is .078, so if you add up the depth of the extractor groove and a field gauge, you come to .118. So there is a possible potential of up to .118 of the case head being exposed out of the chamber and it still being safe to shoot. With the savage bolt head being .116 deep, I am just under to right at that limit if I set it up to where the bolt head just kisses the barrel. I will also be changing it from headspacing off the rim, to headspacing off the shoulder. Well, you never learn anything if you do not try. Ok, so what about a barrel? I could buy a barrel blank and thread/chamber it. Or I could try and rechamber a existing barrel. Since match bullets or just any decent quality bullet in .310-.311 diameter are significantly limited when compared to 308, I figured it would be easiest to just use a 308 bore. Some of the older Finnish mosin nagants had 308 bores and they still shot all the ammo they had through them with 310 bullets with no issues. I personally have shot 310 bullets out of 308 bores with zero issues. Some people act like it is a big deal and will scream that you will blow up your gun if you do it. That is not the case. 310 bullets will go through a 308 bore fine. I'm sure I will still get some comments about it though. I will be handloading 308 bullets 95% of the time anyways. I got wondering about what barrels I could use, possibly without having to set it back. Comparing different rounds, 7.62x54r is larger in almost every area than 308 with the exception of the neck. I think if you run a 7.62x54r chamber reamer into a 308, it would clean it all up except for the neck. I decided to take a chance and try it. There was really no other option other than a new unchambered barrel, or setting one back. And at that point I would be better to just get a blank than setting one back. Off to ebay I went and I found a good used take off factory savage 308 heavy barrel for a really good price. I then order a reamer from PT&G. Once those came in, I slowly started reaming the chamber by hand, going really slowly, using lots of cutting oil, and cleaning the chips often. It cleaned up the old 308 chamber great. I tested several pieces of new brass and loaded ammo in the chamber, and using the bolt head, cut the chamber till the bolt head just barely kisses the breech face when the shoulder touches the chamber. You can see the 308 neck area is still there, but all of the 308 shoulder and case body is gone. We will see what happens when I fire it. I also went ahead and threaded the muzzle 5/8-24 in my lathe, cause why not. OK, barrel done, bolt head done, now to find a actual rifle. So which model to use? I know I need a long action, but I kinda want a detachable magazine if possible. Mag fed long action savage. That limits my options a little. But I actually have one already. It is a model 110 tactical in 300 win mag. I have been very happy with it and it is very fun to shoot. It uses AICS pattern magazines made by MDT. I test the magazine and they will fit 7.62x54r with room to spare. I will need to make a spacer for the rear, to keep the round from coming too far back and letting it come up above the rear of the feed lips, but that should not be hard. Off to gunbroker I go and I find a almost like new 110 tactical in 300 win mag, identical to the one I already have, and it was only $550. I get it home, tear it apart down to the action. I install my modified bolt head, and my rechambered barrel. I set the headpace to where I feel a tiny bit of drag closing the bolt. With the firing pin removed, I chamber and eject a few rounds and the bolt closes fine and ejects fine. Before screwing with the mag, I decide to give it a test fire and see if the thing even shoots and if I get anything alarming with the cases. I started out with some cheap wolf steel case and give it a try. I would be lying if I said I did not put one hand on the butt pad, my other on the grip, hold myself back away from the gun as much as I could with outstreatched arms, turn my head and close my eyes on that first round. It fired and nothing bad happened. I ejected the case and it looked perfectly fine. No bulging, no lines on it, no case head separation, neck looked fine, and the primer looked fine. I fired the remaining 19 rounds with zero issues. I did not even have a scope on it, I just pointed it into the berm at my home shooting range. I give it a good cleaning and inspection and nothing was amiss and everything looked fine. I then decide to try some brass case ammo. I get a box of ppu and repeat the same test. All the brass looked perfectly fine. Zero issues and it looks no different than if it was fired out of one of my mosin nagants. Necks look fine, case head looks fine, no case head bulging or head separation. Nothing at all wrong. So far, this seems to be a success. I give it another cleaning and inspection and find zero issues. I mount up a cheap scope I had laying around. Now for the magazine. Lets see if I can make it work. I called MDT and got a spare follower and mag spring from them. That way I can mod that one and if it fails, I still have the original one to put back in. Tht way I do not mess up a expensive mag. I measure what I need for a spacer, design it in fusion 360, then 3D print it. I trim the follower a bit and install it. It prevents the rounds from coming too far back and the rim jumping behind the feed lips, causing the rim to stick there. However when firing, as you cycled the bolt forward, the bolt had a tendancy to push the next round forward, then pull it back when opening bolt, causing the rim to catch on the round under it and get rim lock. OK, so make another spacer to restrict forward movement. I measure, design, and print a spacer for the front of the mag and trim the follower. I retest and I went through 20 rounds with no feeding issues and no rim lock.  Well, How does it shoot? Most factory ammo is usually around 2 moa for brass case, 2.5-3 for steel case. But that is more so just the quality of the ammo and not so much the gun. Now when I handload, it shoots great. Here is a load I worked up using 168gr hornady a-max and some win 748 powder. All groups are 5 rounds at 100 yards.   Sorry there are not many pictures of the build, but there are not really many to take. They would just be pictures of a barrel and a bolt head, that really would not look much different from other ones. The completed gun really looks no different on the outside from any other savage, and you would have no idea it was 7.62x54r until I told you. All in all I had a lot of fun building this rifle and I now have a very unique one. |
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