Questions for the re-barrel experts

[TonyBen]

Question 1: when the barrel is set to proper headspace, what is an acceptable gap range between the most forward surface of the bolt and the most rearward surface of the barrel? In other words; how to verify that the case head is fully supported?

Question 2: What is the factory barrel torque spec?

Tony.

[LoneWolf]

Question 1: I let the gauges tell me.

Question 2: No idea haven't pulled a factory barrel in years, but I use 60ftlbs personally.

[gbflyer]

Not an expert.

I measure from the front of the bolt nose to the bolt face. Last one I did was .118. I like around .005 bolt nose clearance for a bench gun and closer to .010 for a hunting gun. Savage spec barrels to have .125-.130 "stick out" on your go - gauge (I think some of the super magnums might be different, I've not messed with or researched those). I stopped the reamer at .123 on this one, giving me .005 plus probably another .002 room after headspace.

If you don't ream the chamber yourself you're at the mercy of the barrel in hand. I've got a factory that's shows .125, a custom that I didn't do that shows .132.

[mnbogboy2]

Not an expert.

I measure from the front of the bolt nose to the bolt face. Last one I did was .118. I like around .005 bolt nose clearance for a bench gun and closer to .010 for a hunting gun. Savage spec barrels to have .125-.130 "stick out" on your go - gauge (I think some of the super magnums might be different, I've not messed with or researched those). I stopped the reamer at .123 on this one, giving me .005 plus probably another .002 room after headspace.

If you don't ream the chamber yourself you're at the mercy of the barrel in hand. I've got a factory that's shows .125, a custom that I didn't do that shows .132.

+1 on gbflyer's numbers for standard cartridges.

This is a good post for those having trouble headspacing when the chamber has been overcut (it happens). Also a good check for go gauge protrusion with new barrels or chambers before installation.

Randy

[bsekf]

How much case protrusion to get the .005 to .010 bolt clearance? Or, what is the bolt face depth?

Bill
.

[LoneWolf]

That would be an action specific characteristic. Even something as precisely machined as a Mausingfield varies up to .007 between actions. I would imagine Savage actions are quite a bit sloppier in that regard.

[gbflyer]

How much case protrusion to get the .005 to .010 bolt clearance? Or, what is the bolt face depth?

Bill
.

For the standard Savage, again the go gauge (notice I didn't say case) protrusion should be .125-.130 That's what you'll get with a prefit or factory. Also keep in mind that go gauges can vary somewhat between manufacturers. From measuring several actions, I believe the factory must shoot for .120 or a little less for a bolt nose to bolt face depth. I use a good quality depth micrometer that reads down to the .0005, not that I can hold it that precisely.

I'm not sure what the max clearance is before it becomes unsafe. I do know that not enough clearance is detrimental to accuracy as the breach can come into contact with the bolt nose under recoil in a minimal clearance situation. Closer to .010 clearance is probably better considering all the crud that can build up between cleanings.

I don't dispute there are varying degrees of precision but I would be very surprised if in actuality that a Mausingfield varies .007 in that area. The fellow seems very particular, I'd wager he couldn't abide that much.

[mnbogboy2]

I measured a few more
savage small rifle bolt head = .1095 depth
Shaw chambered .221 fireball with PTG go gauge = .121 protrusion
Savage factory 30-06 chamber with PTG go gauge = .125 protrusion
3 savage large rifle bolt heads = .118, .115, .1145

The only small rifle bolt head I have and the .221 Fireball barrel were paired up before. When head spaced at .002 looks like there was about .014 between the bolt nose and breech face.

Because the bolt heads vary as much as they appear we must continue to "measure & remeasure" before making a move.

Thought provoking post

[TonyBen]

Thanks for all the info!

In summary; looks like Savage factory torque (after some more research) is 60 to 70 foot pounds but home builders commonly use 30 to 35 foot pounds with anti-sieze.

Bolt nose to breech face 0.005" to 0.010." I'll include that in my video as well as chamber reaming if bolt to breech gap is too long. I'm going to assume that the majority of people that change barrels don't know to check this or don't care.

This info will be used in my re-barreling video.

Tony.