Data on end of barrel blank?

[rockrat]

Wondering if this is considered the breech or muzzle end. Remember reading about this many years ago, but time is not friendly sometimes, just plain forgot.

[KCSO]

In rhe barrels I buy the marked end is the breech. You need to get this right as cut rifled barrels are slightly smaller at the muzzle end and reversing the tube can lead to poor accuracy.

[Willbird]

Actually I have read that some makers stamp the big end so you can use it for the breech end, there is nothing in the cut rifling process that would make one end smaller than the other with consistently.

Bill

[leftiye]

Yup, but there may be microscopic burrs running in the direction the cutters were moving when they cut the rifling. This should be read as burrs laid over towards the muzzle.

[JIMinPHX]

I did not know that. From now on I'm going to slug both ends of a blank before using it.

[leftiye]

Running a patch from both ends should (no guarantee) tell you which way is which.

[dubber123]

Even the very inexpensive blanks I just used have a consistant taper. The machinist turned a brass plug that fit snugly in one end of the bores. It wouldn't come close to starting in the other end.

[Willbird]

Even the very inexpensive blanks I just used have a consistant taper. The machinist turned a brass plug that fit snugly in one end of the bores. It wouldn't come close to starting in the other end.

No rifling process other than maybe hammer forging creates a taper(and then only if you used a taper mandrel). When taper was desired in rifle barrels it was generally lapped in. Choke boring is used in some euro 22 target rifles, but they achieve it by leaving the muzzle end of the barrel blank larger at the muzzle, so when they button rifle the muzzle ends up a touch tighter.

Cut rifling for example, the cutter completely traverses the bore and is retracted on the back stroke, it is fed out .0001 then cuts each groove, than another .0001.....the cutter is not moved while cutting the barrel. Button rifling the uniform outside dia blank has a button pulled through it's bore, then afterwards it is contoured(and then it is hand lapped if it is a premium grade bbl)....if it were contoured beforehand the muzzle end of the bore would be larger than the breech due to the "snake swallowing en egg" nature of button rifling.

Many rifle barrel blanks are hand lapped, and the last 1" of the barrel is supposed to be cut off for final use, the breech 1" gets removed when you chamber the barrel.....this is because of the nature of the lapping process,they do not push the lap clear out of the muzzle end of the bbl so that portion is un lapped.

Bill

[MtGun44]

Call the bbl maker.

Bill