6.5cm is cratering SRP OK?

[nmkid]

Carlsbad(forum member) just did the bolt on a rifle for me. I was having the same problem as you are. Peace of mind for me.

 

[ebb]

After looking at the pictures, I would not give it another thought.

 

[Kracken McGraw]

When you read up on the br4, it says people see more flattening of primer because it’s a little softer material to make things work better in all Benchrest type rifles. I would switch to the 450 or 7 1/2 and see if it helps.

 

[HTSmith]

yes it was indeed first firing of starline brass, but i did FL size it, first

That may have only made it worse. Do you have tool to accurately measure the headspace of your unfired rounds compared to your fired brass? Will your fired and still unsized brass fit back into your chamber without much effort?

 

[ronsatspokane]

Shoot more worry less. Unless those loads were developed and fired at below zero temps and you plan to shoot at 100 degree matches, I would not worry. But that's me. Everyone has their comfort zone.

 

[johnfkingmatrix]

That may have only made it worse. Do you have tool to accurately measure the headspace of your unfired rounds compared to your fired brass? Will your fired and still unsized brass fit back into your chamber without much effort?

no the only thing i have is a go gauge for when i installed barrel, and a micrometer for reloading

 

[6.5 forever]

After looking at the pictures, I would not give it another thought.

This is my vote.

 

[HTSmith]

no the only thing i have is a go gauge for when i installed barrel, and a micrometer for reloading

My suspicion is that your unfired brass headspace measurement is very short compared to your chamber headspace. This can happen with new brass even if your chamber headspace is right on the money. Easy to test the theory. Resize minimally--neck size only if your fired brass will fit back into the chamber, load em and shootem. It does look like you've got a rather loose fit between the firing pin and the boltface hole, but this might fix it.

https://bulletin.accurateshooter.com/2020/01/gun-info-101-headspace-defined-and-illustrated/BTW you need to have a way to measure

 

[williepete]

I am having the same issue
tried different brass winchester lrp
Lapua srp
alpha srp
tried different primers
federal 205m
rem 7 1/2
cci 450
all did the same thing
your fireing pin hole is off center and too big just like mine
I have fired close to 1000 rounds with this bolt and yes it keeps getting worse
I am done with this bs so I ordered a custom bolt from ptg the only down side is the 3.5 month wait time
i should get mine in october. willie

 

[HTSmith]

I am having the same issue
tried different brass winchester lrp
Lapua srp
alpha srp
tried different primers
federal 205m
rem 7 1/2
cci 450
all did the same thing
your fireing pin hole is off center and too big just like mine
I have fired close to 1000 rounds with this bolt and yes it keeps getting worse
I am done with this bs so I ordered a custom bolt from ptg the only down side is the 3.5 month wait time
i should get mine in october. willie

Curious do you have a way to headspace the chamber when you get the new bolt? It may be within spec, but it may not.

 

[fatelvis]

Carlsbad(forum member) just did the bolt on a rifle for me. I was having the same problem as you are. Peace of mind for me.

I agree with NM, Carlsbad does wonderful work. To top it off, he is very reasonable and very quick with his turnaround. I’ve had a couple bolts done by him, and they are simply works of art!

 

[williepete]

Curious do you have a way to headspace the chamber when you get the new bolt? It may be within spec, but it may not.

Yes I have built all my guns from scratch I am gun building tool poor.
may have to lap the lugs and head space again I thought about having the bolt bushed but that wont do any thing for the 10k cleareance between he bolt and the bolt race the new bolt will be grined to 2k cleareance for a nice fit.

 

[Coyotefurharvester]

no the only thing i have is a go gauge for when i installed barrel, and a micrometer for reloading

Than you will need to use the spent primer method to measure your case head clearance. Get the bolt bushed, for sure. Carlsbad another thumbs up.

 

[Bill K]

Just proceed or use a primer with a thicker cup measurement. A lot of actions will do this. One reason some bush the bolt face/firing pin hole.

 

[6.5 forever]

I agree with NM, Carlsbad does wonderful work. To top it off, he is very reasonable and very quick with his turnaround. I’ve had a couple bolts done by him, and they are simply works of art!

Carlsbad bushed my REM 700. Problem solved.

 

[fkimble@charter.net]

yes it was indeed first firing of starline brass, but i did FL size it, first

Why FL size new brass? Would it not chamber. FL sizing probably increased headspace even more, making the situation worse!

Frank

 

[wboggs]

Carlsbad bushed my REM 700. Problem solved.

Do you have contact info for Carlsbad?

 

[johnfkingmatrix]

just to clarify: is there accuracy issue/longterm damage from NOT bushing bolt?
i can live with ugly primers if thats the only effect

 

[Kracken McGraw]

just to clarify: is there accuracy issue/longterm damage from NOT bushing bolt?
i can live with ugly primers if thats the only effect

No, not unless it pierces one.

 

[fatelvis]

Do you have contact info for Carlsbad?

I just messaged him and he said he doesn’t bush AR15 or AR10 bolts because they are hardened. Just search his name on this site and message him.