No, it starts a few inches before the powder charge. It shoots the 250gr Thors fine. I posted the target in my MR range report. I just don't like a bullet that loose over the powder while hunting. If it moves off the powder, and I get a shot at an elk before checking it. I've ruined the barrel, and maybe my face.
I don't have the .54 Renegade anymore, and it had a GM RB barrel anyway. I just mentioned the .54, because it's the only way to shoot a sabot for elk in Co.
I just bought two new files, and knurled the hell out of the .502 Thor. No joy.
I tried the same deal with an Optima at CVA. They make you send it back and they try a Powerbelt in the barrel. Of course it has no problem, and they say the barrel is fine. Losing battle.
I might be making a deal for a new Apex. I'll use the ML barrel for deer with sabots, or Thors if they fit, and i'll use a .270 barrel for elk. Done deal.