Step or 11 degree crown?
- Thread starter Rubikahn
- Start date
I do both, yes, at the same time...an 11 degree crown recessed about .06.....accidently set the compound at about 10.5 degrees one time....damn thing wouldn't hit a barn door at 7 paces....recut to 11 degrees and presto...a one holer....very important, that 11 degrees
I've owned a good number of accurate rifles and some had the 11º crown, others were stepped. If there was any real difference, It was not apparent to anyone shooting these rifles. I think it is more a matter of personal preference than any advantage in accuracy. As far as button rifling goes, I would suggest that to set up to do it properly would buy you a lot of fine barrels, already rifled and ready to go. Regards, Eagleye.
I believe the reason for the stepped crown is that a flat crown is very easy to damage. And the 11° crown was developed by USAF (?) armourers for boat tailed bullets and had something to do with a percentage of the slope of the boat tail.
I don't purport to be an expert but have seen a lot of different crowns over the years. I believe that as long as they are square and true to the bore that straight or angled doesn't really matter. The rest of the story is just personal preferance.
It is an exceptional barrel that is actually drilled perfectly straight . The bore in the end appears to be perfectly centered because the barrel blank was turned between centers. If the barrel was cut back and then put between centers in a lath again the outside most often turns out of round as if it were a cam shaft. This proves that the bore is often plunging to some degree towards the exit point at the muzzel. If the bore is then crowned with a single point tool it can look proper but it is not square to the bore. The crown really has to be cut with a piloted cutter preferably held in a floating reamer holder that will actually align it with the true bore angle and not just with the exit hole on the end.
This creates a true squared exit point and good control of the exiting gases. Done otherwise and you are making a modified hypodermic needle type of muzzel.
It is an exceptional barrel that is actually drilled perfectly straight . The bore in the end appears to be perfectly centered because the barrel blank was turned between centers. If the barrel was cut back and then put between centers in a lath again the outside most often turns out of round as if it were a cam shaft. This proves that the bore is often plunging to some degree towards the exit point at the muzzel. If the bore is then crowned with a single point tool it can look proper but it is not square to the bore. The crown really has to be cut with a piloted cutter preferably held in a floating reamer holder that will actually align it with the true bore angle and not just with the exit hole on the end.
This creates a true squared exit point and good control of the exiting gases. Done otherwise and you are making a modified hypodermic needle type of muzzel.
Rather than use a piloted cutter, I use a gauge pin in the muzzle, and indicate the barrel in true. If the bore at the muzzle was at an angle to the axis of the barrel, I think that the indicator would pick it up. The worst barrel I've seen from the standpoint of a curved bore was a Rem. 700. On centres, the barrel seemed OK, but when cut in the area of the rear sight, the bore was about .030 off centre.
- Location
- calgary alberta
I have tryed all types of crown angles over the years, I suppose in theory 1 angle may be better, but as long as the crown is truly square to the bore and free of nick,dings, burrs etc I have seen no appreciable difference.
Typically I use a recessed target crown on the rifles I build, that way the most important part of the barrel is protected
Typically I use a recessed target crown on the rifles I build, that way the most important part of the barrel is protected
