The explosion of mostly cheap (except for the "sniper" and some carbine versions) Mosin-Nagant rifles has also led to the realization for many that these guns can be shot often and relatively cheaply (especially regarding the price of other similarly powered ammo) because of the ready availability of tons of cheap surplus ammo. Even the more premium supposed non-corrosive ammo is a bargain. And ammo that is more or less reliably non-corrosive is still lots cheaper than the commercial stuff for similar calibers.
I fully understand that the round is similar to but NOT INTERCHANGEABLE WITH the .30-06 round. Which means it's also similar to the .270 caliber round. AGAIN, THEY'RE NOT INTERCHANGEABLE ROUNDS AND IT'S ABSOLUTELY UNSAFE TO SHOOT A ROUND IN A GUN NOT SPECIFICALLY DESIGNED FOR THAT ROUND.
Common sense will tell you why I put the above-warning in caps.
So point it, there are lots of guns already made to withstand the kind of pressure that the 7.62 x 54r generates. It's not actually superior in any way, in my opinion, to the .30-06 round except in it's absolute inexpensiveness, which alone is enough to justify buying a low priced but modern made gun to shoot this round.
How about an H&R single shot rifle to shoot this round? Bring it in under $200 with a cool sight system and a shoot through scope mount rail, for this round can travel some yards accurately and you'll want a scope for distant work, leaving the sights set up for close range work. A couple of rails ahead of the hand guard would be nice for mounting a flashlight and laser and folding bi-pod. And maybe an interchangeable shotgun barrel for the poor man's combo rifle.
It would work in any gun chambered to withstand the high pressure of the .30-06, in fact, I've read that it's been referred to as the "Russian .30-06". Again, these calibers are not interchangeable between guns.
But gun makers could chamber a gun for this round, and easily it would seem. Any magazine fed gun that takes a high pressure caliber like this one or of more pressure could be chambered and manufactured for. Numerous bolt actions by numerous makers. Lever actions like the Browning BLR that are magazine fed. The Remington pump and semi-auto rifles that are magazine fed. Any single shot, like the Ruger No. 1 or the much cheaper H&R single shot rifle.
A reasonably priced modern bolt action in the 7.62 x 54r wouldn't be hard to make either. I'm sure there are many other guns I'm not thinking of that could be made in this caliber.
You'd want a gun that had the most durable finish possible, because even though a lot of the Russian and eastern bloc surplus ammo is marked non-corrosive, guess what? Some of it is still corrosive. So generally a good cleaning involves cleaning it for both corrosive and non-corrosive ammo ingredients, just be to sure. it would seem a good parkerized finish would be the best bet.
The sights on the Mosin-Nagant rifles I've seen are adjustable out to hundreds of meters. I've read internet claim of some shots at incredibly long distances, measured in multiple football fields in length. What I do know is that folks standardly get off long shots of between 100 and 300 yards with great accuracy with unaltered, basic guns that go for $100 everywhere, and that's just wild considering the low cost of the ammo.
High ammo prices for some calibers, particularly rifle rounds, can motivate shooters to buy guns for which cheap ammo is readily available. It may not be the guns they usually hunt with or shoot with or carry for defense, but it's the guns they shoot often to practice because the ammo is cheaper than for their standard carry gun.
For instance, lots of my friends who ordinarily are not inclined to shoot, say 9mm guns, have bought them in the past decade simply due to the low prices on surplus ammo that make the guns much cheaper to shoot than some other handgun caliber they prefer to use and carry on a daily basis. Many like the .40 caliber and the .45 ACP, but shoot the 9mm because it's cheaper.
Same with the 7.62 x 39mm, and in my recent experience, the .223 ammo that is good shooting surplus ammo and is very reasonably priced compared to commercial ammo.
Going back to the 80's and early 90's, lots of folks I know bought a cheap but durable and reliable AK-47 or SKS when .223 ammo wasn't as cheap as it is now compared to the price of 7.62 x 39mm ammo. The much lower price of AK ammo made the AK attractive as a weekend shooter for my friends, to take to their country and family places and acreage for shooting fun.
Some folks I know were also concerned with availability of ammo and magazines and wanted to stockpile large amounts of ammo in case laws changed and the availability of such items became limited or eliminated by law. Which it did.
But politics are beside the point here. Cheap and plentiful ammo that is well designed for hunting a variety of species and for very long range target shooting is the point, and it'd be nice to have something other than the Mosin-Nagant to shoot it out of.
Something American made.