If the muzzle appears to be OK and measures that way, it may be OK, but since Douglas themselves used to advise cutting, well I'd do just that. I feel 2" might be too much - however, since I've built a lot of modern rifles with custom barrels and am used to removing 1/2" from each end, I'd personally cut it just to be certain. Afterall, it is a match rifle. Since the breech end on a muzzleloader does not require a perfectly introduced reamer and is threaded at least 1/2" deep, then the powder charge taking up a certain amount, the ball will be starting well up the bore so there is little or no reason to bob that end - all in my opinion, of course.