Green Mountain barrels

[Daryl]

My GM HMR barrel that I shortened , threaded and re-chambered, shoots well under in inch at 100 meters with Hornady and Federal 17gr. Vmax in my little Martini. It is/was .920" and was their fluted stainless bl for a Ruger .22 bolt gun. It is now 18 1/8" long.

[trotterlg]

I have a very small lathe and no follow rest, I can get a GM blank to a roughed sporter contour in about 2 hours. With a larger lathe with a follow rest I could do much better, even a follow rest would probably cut 45 minutes off it because I could take deeper cuts. GM mostly (I think) is in the business of supplying really good high volume production barrels, they are really good at boring and rifling them, but no custom work, they seem to want to leave that to the final user. Probably why you can buy a nice raw 17 or 20 cal rough blank for $45.00 or so. If you have more time than money it is sure the way to go. Larry

[rick w.]

I reckon I kinda dislike tapering on the lathe. Kinda like watching paint dry except the paint can fall off the wall sorta speak with tapering.

I have a smallish(light) 12x36 Atlas benchtop lathe. I taper between centers with an offset tailstock. I am not sure weight of the machine comes into play just a lot in my case, but of course, cannot hurt...........a good heavy lathe is right nice; the Monarch comes to mind there some. I constantly look over the fence at new lathes. I am envious of those folks that have pneumatic or spring loaded follow rests, none here, I cannot see how my fixed finger follow rest would help me with the tapering. I have tried the bumper method, a piece of brass on the tool post, but did not work real well. Chatter can(usually) comes into play in the middle of the barrel. I hate to say that I have resorted to the steady rest at times in the middle, then move it, etc. Varying the speed, rate, depth, tool grind etc etc ..........sometimes helps me, sometimes not. With that, I have learned how to draw file some. Not a pretty sight at first, but comes around eventually when you eventually get down to a #1 taper ...............just a bit of fun huh?

A standard #3 taper is about 0.625" in a typical finished length, so taking down a 1.060" straight, takes me a while with a 0.010" cut per side. Kinda embarassing with the big boys, but what I got. I usually take two easy afternoons tapering a barrel like that. I am somewhat touchy about putting heat into the barrel and how it effects the centers' loading. One can put a lot of heat in a barrel tapering, and I am of the opinion tis not a good thing. All steel stretches with heat..........to me kinda a dance; gotta know when to quit. The barrel's history plays a role to me, if I believe it is one that has little or no destressing, I kinda sneak up on the finished taper, and hope it stays reasonably straight. One also notes that the standard #3 taper at most places is not a straight taper, it has a contoured taper(has a big arc) component; which is harder for the little guy to do. One approach is to use a tracer type apparatus, most of those setups are homebrew and quite intensive visually.

I guess you can tell, I do not like tapering on a lathe. I still do it, but dragging my feet(#14's) all the way. Most of the larger barrel blank makers will make about any taper you want with the initial barrel buy. Some charge 40 bucks or so for making up a new program for their machines, if the taper is in the database, you got it with the barrel. Some will taper anything you send them, just have to do a little homework and inquire. There are a few that will not as well.

My GM stuff has been ok for me, but all have be tapered by myself from the delivered straight barrel. My method is pretty slow, but have not noticed too much enlargement of bore; I think keeping heat out of the system the best I can helps with that, just an opinion. I try not to get carried away.........

I admire the guys that do complex tapers on their home equipment, takes time and effort do so; most guys have little concept of how much work tapering a barrel really is for the home guy. Then some of the FFL bread/butter guys have to be good($) for the barrel blank if something bad happens during the operation.

I am pretty slow, but gots the time.

[MrMajestic]

If you have $1/2 mil you could buy a CNC Quadrex with upper and lower turrets and turn simultaneous with them for support. Flood coolant for temperature control. It would make quick work of it but you would need to do a couple of barrels to pay for it!

[MarinePMI]

I think rick w. nailed why most gunsmiths avoid contouring barrels...time. Which for the gunsmith with one, maybe two lathes, is money since they could be doing other tasks that generate more money.