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Posted: 8/2/2006 6:34:59 AM EDT
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Are there any AR barrel makers out there that cut the rifiling after the barrel is profiled? It would seem to make more sense to do it that way, but it seems that everyone profiles the barrel after it is rifiled. |
| Not that I know of, nor do I see why it would make more sense to do it that way from th barrel makers perspective. Instead of selling blanks for any and all weapons, any and all chamber, any and all profiles you limit yourslef to one rifle, one contour, etc. Great way to get stuck with barrels and have slow delivery times. |
| It's just that I read an article recently that my own experience has shown to be true. That turning down the outside diameter of a barrel will cause the inside diameter to increase. Generally speaking the chamber end of a barrel is a larger dia. than the muzzle end which means that the bullet starts out in a tight bore and exits out of a loose bore which is not an ideal situation for great accuracy. I think this is a big reason that bull barrels are generally more accurate. It would seem that cutting the final rifiling after the barrel is profiled would eliminate this problem. Am I crazy, or is there something to this? |
| Most precision custom barrel makers (Krieger, Broughton, etc.) that sell to the benchrest/accuracy market will lap barrels after profiling, but rifle before profiling. The changes in diameter due to profiling are small and can be corrected by lapping. Mass-market barrels are generally not lapped after rifling, but button-rifled and hammer-forged barrels generally have a smooth bore without lapping. Hammer forging produces the profile at the same time as the rifling, and buttoning can be done after profiling (I don't know why it wouldn't be done that way). AFAIK, only the high-end custom barrel makers use cut rifling, so the whole issue is probably moot. |
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Just as ronemus said, Krieger laps after profiling. When I order Krieger blanks, I order them within about 5% oversize so I am removing very little to no metal during profiling. I typically want to do the fitting at the gas block seat myself, but I have them profile the rest of the barrel right where I need it. As for the barrel making process, have you seen my barrel making page? How a barrel blank becomes a finished AR barrel |
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