I acquired a a rifle and I can't seem to find any info on it at all. It's a NEF single shot, short barrel, break away and chambered in what I thought to be a colt 454 but am being told that they never made any nef chambered in 454, just 45... I've seen pictures but the ones I've seen pictures of didn't have a 4 stamped after the colt 45 stamp. Its also got 454 casull stamped when you break it open.