Ever wondered what your bolt nose clearance measures?

[hoz53]

What if the front of your lugs contact the outer ring at .007 but you had .050 nose clearance?

yeah that is wat i was wondering

 

[mikecr]

Within 0.005" for coned breech. At least for BAT actions & finished barrels.
I don't know for sure as I haven't measured it, but I assume a tape (like grafoil) would be used as a Go/NoGo indication.

If you let the clearance get a lot larger I would think it would hurt primer pocket life.

 

[Dusty Stevens]

Within 0.005" for coned breech. At least for BAT actions & finished barrels.
I don't know for sure as I haven't measured it, but I assume a tape (like grafoil) would be used as a Go/NoGo indication.

If you let the clearance get a lot larger I would think it would hurt primer pocket life.

If it was .020 you couldnt get that solid brass base to flow thru that crack at 100,000psi. The spec on your reamer and the gunsmiths skill at keeping it that size is what helps the base from expanding. Then you get the correct sizing die and maintenance with a ring die and itll double your primer pocket life.

 

[Macropod]

With a cone breech, remember the clearance of the extractor with a case in place. Too small a clearance and the extractor may be jammed when in battery depending on the action.

 

[DaveTooley]

You guys are talking about a section on the case that we don't have any control over. Too much pressure primer pockets go away. Fit the chamber to tight and you have extraction issues as the FL die doesn't touch that area. If FL die did reach that area it would require a tremendous amount of pressure to reduce the diameter not to mention an oversize body on the die. I spent several decades trying to fool Mother Nature with tight chambers. Never worked.

 

[338 Mollett]

Well said Dave !

 

[atblis]

I am going to dredge this up rather than start a new thread.

Put a Remington Factory takeoff 300 RUM barrel on a new Remington 700 action. Headspace gauges correct with a 0.1875 recoil lug (closes on go, won't close on nogo). I did not determine the bolt nose clearance before assembling.

Doing the solder thing, I get 0.016". Am I going to die?

ETA: Just measured my factory assembled 700 in 300 RUM and it measured 0.026" Huh.

 

[AWLEAPHART]

20 years ago we use to check this with some type of thick paper. Basic works the same way.
A Leaphart

 

[Dusty Stevens]

I am going to dredge this up rather than start a new thread.

Put a Remington Factory takeoff 300 RUM barrel on a new Remington 700 action. Headspace gauges correct with a 0.1875 recoil lug (closes on go, won't close on nogo). I did not determine the bolt nose clearance before assembling.

Doing the solder thing, I get 0.016". Am I going to die?

ETA: Just measured my factory assembled 700 in 300 RUM and it measured 0.026" Huh.

this is the difference in custom fitting or a one size fits all. And you can see that remington lets them go at .026. I dont think they were concerned with you reloading that RUM and getting the base to the right size, if they ever even checked it but they did want it to close with a leaf stem in there.