Hard bolt Lift

[martyj]

I have a Stiller tac 338 action and Broughton barrel in 7mmx338 lapua and shoots well with new brass.
Second firing bolt lift is stiff by ejector. I backed load off from first firing where bolt lift was fine 4 grains and still is stiff.
Im shooting 180 berger with 87 retumbo lapua brass.
On initial firing of brass bolt lift was fine with 91 grains of Retumbo while working load.
Did the same on Petersen brass to that came with rifle.

 

[Eric H]

If it was me I'd anneal after sizing. That may solve the problem.

 

[Dmagna]

I don't know much about this cartridge but do you have to turn the necks on the brass and trim? Might be tight brass issue

 

[martyj]

Why would it just get stiff on second firing even though first had more powder in it and should of been higher pressure.
Im kind of leaning towards necks need to be turned like you mentioned.

 

[Eric H]

Why would it just get stiff on second firing even though first had more powder in it and should of been higher pressure.
Im kind of leaning towards necks need to be turned like you mentioned.

That's a good point

 

[North Idaho Hunter]

Have you bumped the shoulder back after that first firing? Depending how the was barrel was chambered for headspace you may be getting crush on that second firing causing the hard bolt lift.

This is easily verified by measuring your cases from virgin - to first and second firing.

 

[sedancowboy]

It is not uncommon to have to back a load off after the first firing of new brass. The new brass uses some energy to form to your chamber. Subsquent firings do not use that energy and therefore you find yourself with a slight over pressure condition. Back the load off a bit and you will be fine.

 

[ShtrRdy]

It is not uncommon to have to back a load off after the first firing of new brass. The new brass uses some energy to form to your chamber. Subsquent firings do not use that energy and therefore you find yourself with a slight over pressure condition. Back the load off a bit and you will be fine.

I agree with this diagnosis.

 

[Bret GRAVELINE Graveline]

Have you checked the OAL on a fired case verses unfired, likely a long shot but won't hurt.

 

[martyj]

It is not uncommon to have to back a load off after the first firing of new brass. The new brass uses some energy to form to your chamber. Subsquent firings do not use that energy and therefore you find yourself with a slight over pressure condition. Back the load off a bit and you will be fine.

I already backed off 5 grains from firing the new brass.
Should I keep going in your opinion?

 

[sierracharlie338]

I already backed off 5 grains from firing the new brass.
Should I keep going in your opinion?

Five whole grains seems waaaay excessive but I'm not well versed on this cartridge either.

 

[WoodTRD]

It is not uncommon to have to back a load off after the first firing of new brass. The new brass uses some energy to form to your chamber. Subsquent firings do not use that energy and therefore you find yourself with a slight over pressure condition. Back the load off a bit and you will be fine.

I may have it backwards but I thought it was usually the other way around? After first firing and resizing closer to your actual chamber spec you had more room and may be able to bump up a touch?

I very well could be getting that mixed up with fireforming and loading for AI cartridges though, just wanted to check myself since I thought it was somewhat the same idea for both.

 

[Bang4theBuck]

I would be looking at two things:
1. Mentioned above- you might be pushing the shoulders back excessively with sizing and when the case expands on next firing it is expanding violently and causing the hard bolt lift.
2. Same condition could be causing you to trim the necks to a dimension that seems correct for the OAL, but once the case expands, you could be shoving it into the throat.

What is your unfired case neck dimension compared to your fired case neck dimension and what is the chamber neck dimension? Could be another cause. Especially knowing the you necked the brass down so much, the necks likely increase significantly in thickness. Doesn't explain why it didn't happen on the first firing but could be a contributor.

 

[Arkansasdad]

I have a Stiller tac 338 action and Broughton barrel in 7mmx338 lapua and shoots well with new brass.
Second firing bolt lift is stiff by ejector. I backed load off from first firing where bolt lift was fine 4 grains and still is stiff.
Im shooting 180 berger with 87 retumbo lapua brass.
On initial firing of brass bolt lift was fine with 91 grains of Retumbo while working load.
Did the same on Petersen brass to that came with rifle.

Try full length sizing the brass and see what happens.