Let me show my ignorance here, but how are barrels choked? Is the blank choked, then maybe OD ground, and then the button die puts the grooves in at the same depth full length and the barrel lands end up choked at the muzzle proportional to the choke in the blank?I have turned threads on thin walled barrel liners and found that if I was too aggressive with the process could effectively choke the barrel. That is fine if threading at the muzzle, but not so much at the breech, LOL.Bill G. had asked about choking barrels after they are in your possession and I have heard of using a pipe cutter (like an overgrown tubing gutter) where the cutter wheel is replaced with a roller. Depending on the ratio of barrel ID to thickness of the barrel wall, and the yield of the material, I can see where it might work fairly well. Lloyd-ss
Maybe like a roller burnishing process, i think it is called? It would keep everything round and concentric.
hopefully letter go's up the ladder to someone in a position that truly understands it and can intelligently respond to it ?
I have heard of using a pipe cutter (like an overgrown tubing gutter) where the cutter wheel is replaced with a roller.
with 3 rollers instead of 2 or one. Macky
What I think most of us ambitious self doers are not aware of .... Is the EXTREME pressure required to physically crush the steel of an AG barrel actually getting any movement. We are likely talking MANY 1000's of pounds pressure doing so making a pipe cutter W/roller or a Knurling tool with roller far too small & weak a method to accomplish this task.JMO ...
Quote from: Motorhead on February 12, 2013, 05:01:53 PMWhat I think most of us ambitious self doers are not aware of .... Is the EXTREME pressure required to physically crush the steel of an AG barrel actually getting any movement. We are likely talking MANY 1000's of pounds pressure doing so making a pipe cutter W/roller or a Knurling tool with roller far too small & weak a method to accomplish this task.JMO ... I agree that it would take some serious trial and error to get this to work. But airgun barrels are fairly soft and the metal can be moved around. I have watched a rifling button die pulled thru a barrel and intuitively I would have thought the connection between the button die and the pull rod would have failed during the pulling process. But it didn't. And think of the thread rolling process that is used to cold-form bolts. I think if the 3 rollers in a roller swaging set-up were narrow enough, and held in a full circular frame (probably not a C-frame) to apply enough force, and fed away from the chuck toward the end of the barrel, that the metal could be made to move. I haven't done any force calculations but I will see if I can.Lloyd-ss
Naturally, it would need to be to a respected member of the forum here. Someone who is competent, experienced AG Smith, has the equipment, and the desire to try it.