Gunsmithing Back bore for threaded muzzle question ???

[runningun]

If a 22 caliber rifle muzzle is going to be threaded to 1/2-28, is it necessary or preferable to "back bore" the muzzle to keep accuracy. The rifle is a 22 rimfire with an barrel o.d of .850 at the muzzle. Will threading the barrel open up the end of the muzzle and cause accuracy to suffer?
Thanks for the help.

 

[mscott]

Re: Back bore for threaded muzzle question ???

Interesting thought. C. Dixon posted something on that a while ago on centerfire rifles, so maybe he'll chime in. You are taking a lot of meat off of that barrel, but I'd bet the quality of rimfire ammo would have a greater effect on accuracy than the threading.

 

[LRI]

Re: Back bore for threaded muzzle question ???

I think with a 22LR your pretty safe with a 1/2~28.

Just so long as its turned with coolant and good tooling.

C.

 

[Mark Housel]

Re: Back bore for threaded muzzle question ???

Chad,

Is this primarily a muzzle pressure concern?

Thanks,
Mark

 

[runningun]

Re: Back bore for threaded muzzle question ???

The primary concern I have is accuracy. I know that we are talking about a 22LR, but it is on a med/heavy barrel bolt action and I would like to keep the accuracy potential. I know that 1/2-28 does not leave a great deal thickness for back boring, but I was wondering if cutting out the rifling in the last 5/8" of the muzzle that is threaded would matter? I agree that ammo selection is important, I have tried several brands of ammo and it does have a significant effect on accuracy.