Is it unsafe to recontour a barrel?

[shawnba67]

I read that as far as accuracy goes its in-advisable to re-contour due to stress relieving. But is it actually unsafe? Also how would turning a barrel blank be different than a re-contour?

 

[7mmRM]

Unsafe? No. Potential to harm accuracy. Yes. More so in a button rifled barrel. Will it? Who knows. I've seen plenty of cut and button rifled barrels contoured after the fact, that seemingly had no adverse effects.

 

[Tactically Fat]

I'd suspect that a lot has to do with the specific steel the barrel is made out of, its heat treat, the barrel platform, the barrel chambering, etc.

Reprofiling a .22LR barrel to sit in a 10/22 chassis is a whole other ballgame than reprofiling a SBR AR barrel in .308 Win.

 

[natdscott]

The accepted best (and by that I mean the most likely NOT to screw up the barrel) way, as far as accuracy is concerned, is to rough profile BEFORE finish lapping and/or before cutting the rifling. The only thing left to do after chambering the rough blank is to slowly remove ~0.050" or less and prepare for finishing.

An easy way to judge if the profile you seek is safe or not is to do some research on popular barrel maker's safety margins for profile. They will ALL go featherweight on their 4130 et al. CM barrels, but most/all will not allow you to even ORDER a barrel in that light a contour of 410 Stainless.

Figure out what your barrel's made of, go look at the minimum contour stated by Krieger or Bartlein for that steel, and if you know what's good for your safety, don't go near that, much less any smaller.

The premium barrel makers operate with EXTREMELY consistent steel, and have safe facilities to strain gauge their barrels at the contours they state. You almost certainly do not, and you probably don't know just exactly what quality steel you have.



But as has been stated, some more information would help us. Whatcha tryin to do?

-Nate

 

[shawnba67]

Ive got a 788 in 22-250 that is 9.4lbs scoped, my 700 is 8.2 scoped and the difference is huge, especially in the field after a mile or 2. So since the 788 gets left at home for being a fatty i thought id shave some of that light bull sporter tube off and loose close to a lb. taking it down to a standard sporter contour should save me close to a lb by bartliens barrel weight diagram. That would make this ole girl useful again, at least for me

 

[natdscott]

Well, just calculate it yourself. CM Barrel steel runs pretty close to 4.5 ounces per cubic inch....I assume that 788 wears CM?

-Nate

 

[2in1evtime]

Might be in your best interest to just re-barrel the action with a new made lighter barrel!!

 

[shawnba67]

Might be in your best interest to just re-barrel the action with a new made lighter barrel!!

how does your plan differ from mine. Apart from the hundreds of dollars it would cost?

 

[bstewrat3]

Make sure to use a gunsmith who knows what they are doing and not just a guy with a lathe who thinks they can do it. Contouring the barrel can potentially impart a lot of stress into the barrel if the job is rushed. Another less risky option is to have your barrel fluted, so you will not lose any barrel diameter but can lose up to a pound of weight on varmint diameter barrels. This should be a cheaper option as well.

 

[55fairlane]

steel has stress in it, if you bore and ream a hole to size then turn the O.D. the bore size can change, or the shaft will stress relive ,and "bend"

on barrel work I won't profile up near the chamber, and I will recut a crown on it, but, depending on caliber I think a new barrel would be honest suggestion...I.E. big calibers with lots of chamber pressure

another thought, if the barrel runs out and there is more stock on one side it could possible throw the balance off and cause an accuracy issue

 

[Hookeye]

A 788 is a 788 IMHO.
Mid weight sporter .22-250 might be a chore on long walks, but in a varmint cartridge..............I'd leave the weight on.