Question for a gun smith

[plinker]

I have just finished fire forming for a 17-223 i have just built the gun shoots great just fire forming and if it gets any better after the cases have been blowed out it will be even better. I put this gun together with a full blank Douglas barrel I turned about .020 off to clean it up before fitting it to the action so its basically still full blank. My question is will there be any stress put in the barrel if i turn the thing down to about .850 on a cnc lathe with plenty of coolant . The barrel is chrome molly



Plinker

[GunCat]

Douglas barrels are button rifled if remember correctly. Conventional thinking is that you should not significantly alter the profile of a button rifled barrel - the stress induced by the rifling process is relived as you remove wall thickness and the bore/groove diameter can change and vary along the length of barrel.

Could you have the barrel cryo treated for stress relief then turn it down? Others that know more on the topic may be able to shed more light on the possibilities here.

[plinker]

I didnt think about it at the time i was doing this.This was the first one i have done and i thought with a full blank i had about 26 inches to make mistakes on. And a friend had a bench rest stock that i could use to try it out. Now i need to give his stock back and the only thing i have to use is a heavy barreled stock. The stress part didnt enter my mind until we started to discussing turning it down. Thanks for the information


Plinker

[mwezell]

Did you cut at least 1 inch off of the muzzle end? The button rifling process does not produce good results in the first inch or so of entry/exit.
I do not recommend contouring the od of a barrel after as the bore does grow some,particularly in button rifled barrels because of the stresses induced during rifling.Cut rifle and hammer forged are not as bad about this as button rifled barrels. Also stress releiving is dependent upon the quality of the material that particular barrel is made of.This is dictated by the quality control at the steel manufacturing level. The steel provider then sells the material to douglas or whoever to their "specs". Again-Quality Control.
Congatulations on your first build!!---------------Mike

[plinker]

we cut some of the end off probably not an inch though. I guess we learn as we go or by our mistakes i guess i should say. Now its either buy or make a stock or turn it down.The trouble is the gun was to be used to hunt with also.