I had an idea that we were on same page, just put it out in case some new shooter might have thought the SKS could have been chambered in 5.56. When I go to the back of property to shoot most time I push my gun buggy with all the junk and whatever that I might need so don't have to walk back and forth. This time I just carried the SKS and a few rounds, I thought I had ear plugs in pocket but that's what happens when I THINK. I must say the carbine really surprised me as to how loud it was, I have a Winchester Mod 70 in 300WM that is not as loud as the SKS. It has the BOSS on the end which reduces the recoil so much that it is a pleasure to shoot. I have shot it with ear plugs because what I read was the BOSS will increase the noise but it was not as bad as I expected. The only other gun I have that is a pain in the ears is a cheap Heritage revolver that has cylinders for both 22 s/l/lr and one for 22mag. The 22mag is extremely loud and whats worse it how in accurate the pistol is, I do believe that you could weld the gun down solid and it would still throw rounds where ever it wanted to go, but it's fun to shoot.
Well, ear pain is objective, I guess. I'd venture that my 3" .357 magnum is louder than my .22 mag 2" NAA Black Widow, though, at least with ear plugs in there is quite a difference. I shot a hog once while walking my place with the .357 as I was carrying it concealed that day. OUCH! Well, if I had to shoot a BG with it, screw the ears...
...but it wasn't pleasant.
I don't have a rifle with a BOSS on it, but I do have this 8x57 Hakim battle rifle. I sat down at the bench one day at a range I was invited to. Guy's wife was in the seat next to me. The blast off that recoil compensator blew the ball cap off her head and sent her ducking to the ground.
I wouldn't wanna fire that thing without ear protection, either. It has a longish barrel, but that don't help much with 8x57.
Anyway, the little Paratrooper IS quite a bit louder, I'm sure, than my 20" SKS. I KNOW for a fact, you can visibly SEE the muzzle flash on a sunny day at high noon.
That 20" gun, though, isn't that bad, mild compared to my hunting rifles, but that 4 inches of barrel seems to make a dramatic difference, you're right.