I have to introduce a small correction. There was no such thing as reduced charge loads for 7.62x54 Russian. The Obrez, which translates as Cutoff, was indeed the weapon of rebels and the poor. How short the barrel would be depended on the need to conceal it. Typically enough to wear under a heavy overcoat or a loose jacket. It was similar in size to the Mares Leg, carried on foot or kept in the cabin.
If you have ever fired a Mosin carbine, you noticed how much louder it was than the rifle. Still a regulation weapon. The Obrez, I predict, will be such an earful that will require extra protection. The muzzle flash will be spectacular. The muzzle jump will be extreme. If that's your gig worth a federal stamp, Godspeed. You will command attention anywhere you go, including Internet forums. Unlike the WW2 partisans or the peasant rebels in Russia, you probably could hand load reduced power ammo.