Discussion in 'Gun Project Questions & Gunsmithing' started by LC Tikka, Jan 28, 2018.
They wont do it. Not without a ton of pain. You would think it wouldnt be an issue but it usually is
I dont give the benefit of doubt.
Old school gunsmiths did contour barrels a lot back in the days of surplus actions and barrels. It takes a certain skill set that fewer guys have these days. A bigger, beefier lathe is not absolutely necessary but it helps a lot. Many of the popular imported machines are flimsier than they look and the smaller tailstock quill is one of the weakest links. A guy can do it the hard way by using a steady rest and working on a short section at a time to mitigate chatter, then blend it all together by filing. No money to be made there. The guys that are or were good at it used a specially ground HSS (or cobalt) tool with more rake than typical and ran fairly fast the entire length with a high feed rate. The barrel manufacturers use high speed CNC dual turret lathes that are especially suited to machining contours.
Tell me about it. I put about 8 man-hours into this one:
Got a "good deal" on some straight contour blanks:
The only person that i can think of that contoured the barrel before making the hole was Gary.. i could be wrong or he may be doing things different now.. i am not sure without asking the horse himself
When I started out gunsmithing, it was common practice to contour almost every barrel we installed. Contouring was done on a 12x36 lathe. Today, I don't turn every barrel from a full blank but I do quite a few and I do alter the contour on most barrels. This work done on a 13x40 lathe. Button rifled barrels seldom move significantly during profiling because they are stress relieved as part of the manufacturing process. Many cut-rifled barrels do move a bit because, while they are made with stress relieved material, the material isn't always perfectly normalized and can warp a bit. I have re-contoured a bunch of hammer-forged barrels with no issues as well.
The very worst barrels I ever had to contour were a couple of cut-rifled barrels from a Montana maker. After struggling with the first one and having to take it out and straighten it after every pass, I threw them both into the oven and cooked them at max temp for a couple hours then let them cool in the oven. This was not the proper protocol for normalizing but it worked well enough to allow me to do the job. If turning from 1.250. to 1.150 was to make a difference, I doubt that you could measure it. WH
I've tapered several Heavy Varmint contour barrels to a #5 taper. I use a HSS tool ground with a lot of positive rake and a chip breaker design. Turn the work slow and feed at .010/revolution. The heat comes off in the chip and the barrel is barely above room temp after a pass. Usually take about .020 depth of cut. I have a hand size piece of saddle skirting leather that I hold the center of the barrel between centers and it keeps the chatter out. It usually takes a couple of hours to do one. Their free or I sure as heck wouldn't do it.
thank you for that info. i have a southbend 13 which is in pieces. it does have a taper attachment. i sure would like to get it running as i also have an import and i always considered the import a very lite duty machine- flimsy is a good way to put it. everything about it is like a toy compared to the south bend and i know the south bend is not a heavy duty machine compared to some others. id love to have an older beefy lathe in good shape thats for sure. right now im concentrating on getting a mill.
i was thinking they may be something more powerful than a flare
I wouldnt stick around to find out. Somebody like that idiot with the underwear bomb if i was on that plane they’d still be talking about me beating that guy
Gary Schneider? I was actually thinking about Krieger. They have explained in interviews and videos that they generally profile first, then drill; starting from the muzzle end. I don't know about all the other cut rifling guys although several of them are former Krieger employees.
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