If it's not going to be full-auto but still a gas arm, I'll take the SKS every time. Designed as the SKS-41, it initially took the 7.62x54R round.
When production actually began, the SKS-45 had been rechambered to the 7.62x39, a new, intermediate, rimless round based on the 7.62x54R, using the idea behind the 7.92x33K.
Ever notice how the bolt stroke of the SKS is long enough to take a full-size round... yet it has a smaller magazine? Yep. That's why.
There were a few made for front-line trials in 1944-45 -- about 10,000 -- and the troops loved them.
My only beef with the SKS is the trigger pull. It utilizes a sliding sear, and as such, the trigger is long, doesn't return when you let off of it, and the sear tends to develop a slope after a while.
You can always take one of the trigger groups apart and recut the sear, but that leads to rehardening and all that is one lousy ***** to do.
I no longer have one, but should I find one that is not overpriced, I will probably buy another. I love bolt actions for accuracy and precision, but sometimes one just needs volume fire. If I do end up with another one, I think I'll end up finding a way to make the sear roll on bearings, much as I do with my Mosin triggers.
Still, there's really not much I would do with an SKS that I can't do as well with a Mosin or a Gewehr. I'm coming to really like pistols and pistol-caliber carbines (blowback versions) for volume fire for any sort of serious activity. I prefer to be able to free a hand if I need it.
It's most excellent for those of us who do not like pistol grips on our rifles, as well. The bayonet serves as a monopod for precision shooting, and if you know a 'Nam combat vet who talks about that war, you might ask him about hearing the bayonets click into place... Some I've talked to say that was one of the scariest things in that war.
Some sniper versions were built. The Russians played with the idea and some prototypes exist in their museums, while the Yugoslavians fielded a M59/66 with a Type 89 (I think) 'scope.
What it all boils down to is an insanely fun carbine that can be very deadly if one should need it to be. Like the M1 Carbine, it's almost an assault rifle, but not quite!