Tight Bolt

[Twud]

You may remember my sticky bolt problem. Using a conservative load in my new custom 6BR the bolt is really tight on the way up.
I decided to go after the shoulders first. Bought a Hornady Headspace Gauge. The turned Lapua brass is very inconsistent from base to shoulder. A fired round mesures 1.167 with the gauge zeroed out on the bushing.
Fired cases measured:
1.171
1.167
1.167
1.157
Subsequent unfired cases neasure:
1.161
1.168
1.159
1.165
1.164

I'd like to bump the shoulders .002", but where would I start?
Also given the variance they all felt the same resistance when opening the bolt. Extraction is no problem.
The fired cases are a random sample.


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[kelbro]

It often takes two loadings/firings to completely blow the case out to fit the chamber. Try one more load and see if the deviations close up.

 

[222Rem]

Did you deprime the cases without resizing before measuring???

 

[cw308]

Are you neck sizing with bushing dies ? Bushing dies didn't work out so well for me . A good FL die non bushing . Brass that is on the thick side as the case expands to he chamber walls a slight variation in thickness will effect length . People who neck size only not all the cases will chamber hard at the same time . My fired cases get shorter by .001 from sized .002 to fired .003 I'm now going to size to .003 to see what effects it will have . Never liked my bolt closing with resistance could gall locking lugs . Will a small amont of wiggle room when where talking thousands make that much of a difference. Once you can size with all the cases the exact size and chamber smoothly is the way to go . Did you have the same chambering issue with other types of brass . Just measure the loaded cases on loaded store bought Match ammo , case will measure .004 from base to datum. I'm testing with alittle more room with everything else the same to see if it really makes a difference . Bullet seating an powder charge does , case space ill see this Sunday. Before I was .0015 to .002 will see if .003 fired case length will change anything.

 

[Comrade Terry]

Twud was last seen: Jul 14, 2013

 

[cw308]

Boy do I feel like a jerk , why does it still show up as new . Was his problem ever solved .

 

[Comrade Terry]

Don't feel that way, CW. It happens to the best of us - sometimes with great hilarity!

 

[Dusty Stevens]

Boy do I feel like a jerk , why does it still show up as new . Was his problem ever solved .

It doesnt show up as new. It probably was down at the bottom of the page with relevant threads not new ones. Thats how most of the old threads get bumped- pure accident. Dont let it bother you nothing has changed since then so the info is still relevant.

 

[cw308]

Thanks Dusty.

 

[Flouncer]

Don't feel that way, CW. It happens to the best of us - sometimes with great hilarity!

"Detective Comrade !!"