6BR problems

[Loki2]

 

[Loki2]

Nothing that I can see

 

[Sniperhandle]

Kind of blurry, But I don't see an extrusion. I would still think the hole size is the problem. I have re-bushed several of my bolts for this reason.

 

[Krogen]

What kind of brass are you using and what in what caliber did it begin life? I see LC 72 which doesn't make sense to me based on the thread so far.

 

[Sniperhandle]

What kind of brass are you using and what in what caliber did it begin life? I see LC 72 which doesn't make sense to me based on the thread so far.

He shows his old caliber of 308 win.

 

[Krogen]

He shows his old caliber of 308 win.

Thanks. I went back and found the .308 reference.

 

[Bill Rodolph]

Firing pin protrusion could be more than is required for a small primer. Couple that with the larger diameter firing pin and this could be part of the problem. Maybe bush the bolt down to the .062 firing pin and reduce the protrusion. As far as load, I know a lot of people run 30 grns of Varget with the 105/107 grn bullets, but I never could. 29 grns was max in the barrel I have. And it shot better somewhat lower. Don't worry about velocity over accuracy and shootability.

 

[muleystalker]

Nothing that I can see

You usually don't have a problem with LR primers, its the SR primers that usually blank on a REMINGTON 700.

 

[AlNyhus]

If you're comfortable that everything is ok, you could try a different primer. That you had to knock a case out of the chamber would be the red flag here, though.

 

[clowdis]

Did you chamber with a 6BR Remington or 6BR Norma reamer?

 

[Carl S]

Like sniperhandle said bush the firing pin hole and turn the pin for proper fit and protrusion.BR4 primers are also a option.

 

[SilhouetteShooter]

Have you looked closely at the tip of the firing pin? If it’s not perfectly round you will see blown primers, the more primers you pierce, the worse that tip gets (flame cutting ).

 

[urbanrifleman]

Tight bore barrel.

 

[Clancy]

What is your chamber neck dimension and the dimension of a loaded round?

Not every batch is the same. I’ve seen some Lapua that measured .272 loaded. Most is .268-.2685.

 

[ctrickett]

Yes, have gun smith check clearance for firing pin, when using hot loads and 30gr of Varget with 108 are hot, that could be an issue
I shoot lots of 6BR at 600, I use 29.0 Varget, 450 primers, Lapua Brass (fired so many times I dont track it)....shoot all 105 hybrids
Also, dont put them on lands....jump them, less pressure

 

[swd]

Show us a good picture of your fired 6BR brass. Turning the firing pin to .062” and bushing the bolt face will more than likely fix your problem. Stock size 700 pins and clearances don't generally handle any of the 6BR chamberings very well at the upper ends of the load spectrum.

 

[rem40xb1]

I sent the bolt off to get bushed by carlsbad

 

[randyc]

I would check if bullet is too far into the lands, if it set a little deeper and try. I also shot 6 BR and used CCI 450 mag primers to withstand extra pressure. 450 mag primers will not hurt primer well.

 

[jnyfeler]

I can explain it like this, If you put a piece of glass over a 3 inch hole you can step on it and it won't break, You put it over a 6 inch hole and it will break. The same thing goes for the cup, The surface area of the firing pin hole is too large to hold the pressure, If you reduce it, It can hold it fine.

Exactly right. And the fact that the problem did not present with a 308 but did present with a 6br is a classic symptom. I've had Gre-Tan Rifles bush a couple of firing pin holes and turn the firing pins for me. I was very happy with his work and turn around time. Sadly, he's not currently accepting any new work.

Jeff

 

[SKWERLZ]

For some reason 30 calibers don't seem to be affected as bad, Once you get to 6.5 is when it starts to show problems, At least that has been my experience. Show a pic of your 308 primers and I will be willing to bet they are "Extruded" This is where the cup flows past the firing pin and into the space between and it and the hole, The extrusion will stick up proud.

Edit: Here is a pic I grabbed from Google, See how the cup material sticks up proud.
View attachment 1603023

I’ve seen that’s well
Big pin 700 that was fine for 308 with LR primers that had issues with smaller calibers especially small primers.

As for the load, always work up.
Lots of the 30 grain and above 6BR loads are shot in custom actions that handle pressure better than the vast majority of factory actions.