Hello guys

I have a spare 8x57 IS (.323) barrel. Somebody has cut it´s threaths away so I´m thinking to do new with bushing the barrel. That´s because the barrels cylinder part is now too short.
So how much "meat" I have to leave round the chambering ? In other words, how thick the original barrels wall should be round the chamfering inside the bushing ?

Small ring mauser is .980" diameter so I would say that would be a safe minimum.

Weatherby does lightweights and ULWT's in a .875 thread. I took a surplus 338/06 and threaded a 1.1" large ring barrel shank cutoff to .875 internally for the barrel. It came out well, but I don't know if I would try anything larger than the .875 for the LR. The bushing just gets too thin. Given the thread depth both inside and outside, it takes a pretty substantial diameter difference to leave any mechanical strength for the bushing. In my case, there was 0.225 difference, bit consider that out of this comes two thread depths worth of 1 in 16 threads and two thread depths worth of 1 in 12 threads. It leaves the bushing mighty thin to put much torque on. I suspect the minimum delta for strength is going to be 0.2" or north of there. This is a separate question from the minimum shank diameter to withstand chamber pressures. I have done some calcs on this, and personally would never go below .875 on an 06 head diameter. With that, I don't see going below about 1.1 for a bushed reciever. You could obviously go smaller on both sides for a smaller base case.

Thanks for your comments. Is there any idea to solder the bushing ?

Is this a military contour barrel or is it a commercial one?

quote:

Originally posted by igorrock:
Hello guys

I have a spare 8x57 IS (.323) barrel. Somebody has cut it´s threaths away so I´m thinking to do new with bushing the barrel. That´s because the barrels cylinder part is now too short.
So how much "meat" I have to leave round the chambering ? In other words, how thick the original barrels wall should be round the chamfering inside the bushing ?

It´s commercial with very short "cylinder" -part in the chamfering end.

Low-temperature silver-solder, with a melting point @ ~ 750F, should work fine. I agree with the 0.875" (22mm) OD.
Regards, Joe

Turn your bushing about .012" to .015" undersize on the OD then stick the barrel in the freezer and the bushing in the oven heat to about 650 Degrees F.

When you put the two together they will be as near one piece as you could get.

Or solder it your choice
Just be sure to use like materials. 4140 bushing on a chromolly barrel

quote:

Turn your bushing about .012" to .015" undersize on the OD then stick the barrel in the freezer and the bushing in the oven heat to about 650 Degrees F.

When you put the two together they will be as near one piece as you could get.

Thanks, I haven´t tried this before in barrel project but procedure is familiar me from other projects.

quote:

Originally posted by kcstott:
Turn your bushing about .012" to .015" undersize on the OD then stick the barrel in the freezer and the bushing in the oven heat to about 650 Degrees F.

Kcstott
Did you drop a zero? 12-15 thou seems like an awful lot for a "shrink fit". 1.2-1.5 thou (0.0012-0.0015) seems like a more likely number