Jim Watson
Member
There used to be a lot of barrels cut off at the breech, rethreaded, and rechambered to get a clean throat, rim and centerfire. I don't know if it is still a popular option.
When C.E. Harris was working on improving 10-22 etc accuracy, he had a source for takeoff Martini barrels. Cut off at breech and muzzle to get clean rifling, he said they shot as well or better than new.
Federal Catalyst primer contains barium oxide and aluminum along with some nitrocellulose to liven things up. They speak of a thermite reaction which will form aluminum oxide. Too fine to grind or a source of wear? There is also a secret sauce package of binders and sensitizers which might include grit.
A research paper shows silicon in all US lead free primers on the market at the time.
That is surely in the form of silica, sand or ground glass which has been used for a long time.
When C.E. Harris was working on improving 10-22 etc accuracy, he had a source for takeoff Martini barrels. Cut off at breech and muzzle to get clean rifling, he said they shot as well or better than new.
Federal Catalyst primer contains barium oxide and aluminum along with some nitrocellulose to liven things up. They speak of a thermite reaction which will form aluminum oxide. Too fine to grind or a source of wear? There is also a secret sauce package of binders and sensitizers which might include grit.
A research paper shows silicon in all US lead free primers on the market at the time.
That is surely in the form of silica, sand or ground glass which has been used for a long time.
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