Let’s not split hairs, the folder is substantially lighter and smaller, though I agree that grenade launcher thing is pointless deadweight and looks dumb.
The heavy barrel though is not an improvement when you also increase the barrel length. Some have pointed out that the terminal ballistics of 7.62x39 are bad and that disqualifies any DMRs chambered in it. But it’s the internal ballistics which are really an issue.
7.62x39 gains almost no speed between 18.5 and 20.5 inches, and the longer barrel will deflect more and therefor, for the same muzzle velocity, be less accurate. The thicker barrel profile only helps to make up for the detrimental decision to increase the barrel length. It’s unfortunate that the gun was designed to look accurate, because those exact design changes condemn it to not be.
You talk about not splitting hairs then you go straight to how two inches of extra barrel "condemn" the design. lol, lmao even.
I believe there are plenty of 30cal rifles with barrel lengths much longer than 20" which are capable of orders of magnitude more precision than you'd ever wring out of this platform so that's a patently ridiculous statement.
Besides you've got a 20" barrel on an SKS, and while those aren't tack drivers by any means it really undermines the concept 20"barrel on a 7.62x39 gun is a catastrophically bad decision. Heck the CZ 527 was available with a 26" tube.
Now it *is* true that longer barrels, for a given barrel profile, are less rigid than shorter barrels for a given length.
But when it comes down to what length of barrel is going to be inherently more accurate it's much more complicated than that, within a reasonable, normal range of barrel lengths (like 10"-30") the dominant factor is going to be harmonics. Where those nodes are has to be determined by experimentation, and in order to do so properly you'd need to experiment with different barrel lengths.
Some manufactures do this, diemaco in particular while developing their C8's made a series of barrel getting incrementally shorter and found the ideal barrel length for their particular action and barrel profile. To figure out which barrel length would have the least whip in the type 81 you'd have to do that type of testing, not just say "oh it's 2" longer so it's going to deflect more". Especially when we're comparing different barrel profiles. And then you have to consider how the barrel will handle heat, that's the main advantage of a heavier profile, not rigidity.
Now, in my opinion, the heavier barrel profile of the SR and LMG more than make up for any loss of rigidity from the marginally longer length. Which is more optimal harmonics wise? I'd really have to shoot every variant more, and at this point while I have a thousand odd rounds through an LMG my experience behind the trigger with the other T81 is limited. I will tell you that I really don't like how thin the barrel profile is on the standard type 81's, i've really given the LMG a few hot suppers and was pleasantly surprised with how the groups stayed consistent, i've seen varying reports about the standard T81 throwing fliers when hot and I could see how that would be case, especially when you'd got that sleeve fit over the barrel and how contact between it and the barrel will change as the barrel heats up. I just don't want any part of that, looks and diminished sight radius with irons aside even.
It's well established that anything touching the barrel with effect it's harmonics and point of impact, just look at the LMG where when shooting offhand folding or unfolding the bipod changes the weight distribution and moves the point of impact a foot at a hundred meters, consistently. It'll still group relatively tight, but the POI shifts dramatically and repeatable.
Now as a final though, the dragunov acceptance spec was only about 3 MOA, and reports i've read seem collaborate them being capable of 2.5ish MOA with the right ammo.
That's more than sufficient for the role they were designed for.
Tactical Imports claims the SR will do 1.5-3MOA.
So I find it *really* funny when people ##### and moan specifically about the accuracy (as opposed to range) potential of these compared with a dragunov, those aren't sub MOA rifles either like many seem to believe.
Not that we're going to try to say that the SR is actually comparable to a dragunov otherwise, but people really overestimate just how accurate rifles used as "snipers" have been throughout history, ww2 era that same 3MOA or so was typical across the board, we're really spoiled today when you can expect a cheap hunting rifle to shoot under an inch at 100m out of the box without any particular effort.