Can't take pictures - too late and camera wouldn't focus anyway, I tried! Itsa "smoothbore" extension now. And aparently thats exactly what was the problem, not barrel wear or anything. 303 isn't big enough I guess, bullet was "touching" at very least.
Barry from Bits of Pieces got me old beat up 308 barrel for my little re-barreling project. I couldn't locate any M1 Carbine barrels and those are way too labour intensive to machine from scratch. Found few barrels in states but no one will ever ship anything across the border anymore, thats it, so much for a free trade.
By the way, my "kinky" Carbine came to me from another CGNer, off EE forum. Thanx bud!
Whenever anybody says "Well its not my gun...I sell it for a buddy of a buddy of mine... I never had a chance to shoot it since I bought it..." or anyhting to that effect - take it as scam artists signature. Nothing less. From now on I only buy something if owner swears by his piece or at least honestly tells me what is the problem.