Blown Primers going from Fed 210M to Rem 7 1/2?

[rockchalk06]

Primers look strange. Outer radius of primer cup usually flattens out before material extrudes out around the firing pin nose.

I concur. I've never seen this before. This is a Large Rifle (210M) from Starline Brass fired from the same rifle before I fired these SP. There is a tad bit of cratering as these are warmer (41.5 H4350 old load) but the outer radius like you said, is flat

 

[rockchalk06]

That green tint on the brass above must be a weird reflection or my phoes camera.

 

[rockchalk06]

I've got to call Bergara in the morning. This is apparently an issue with the B14 and small primers.

 

[Jcann]

I don’t see pressure issue here. Lots and lots of shooters have had issues with SP brass. Most fix their problem after they have their firing pin brushed.

 

[rockchalk06]

I don’t see pressure issue here. Lots and lots of shooters have had issues with SP brass. Most fix their problem after they have their firing pin brushed.

That's what I'm reading as well. I need to find out what this costs. It might be cheaper to go back to LP brass and keeping looking for 210M's.

 

[Jcann]

GUNSMITHING SERVICES: STRIKER PIN BUSHING: M7, M700, M70(PF AND CRF), ACCURACY INTERNATIONAL, BERGARA, HOWA 1500, & RUGER RPR

A relatively frequent complaint with M700 and Accuracy International actions (and others) are cratered primers with factory made ammunition. The root cause of this is from excessive clearance between the striker and the hole through the bolt face. When fired, the primer cup flows into the void...

www.longriflesinc.com

Chad at LRI is one of the best

 

[rockchalk06]

GUNSMITHING SERVICES: STRIKER PIN BUSHING: M7, M700, M70(PF AND CRF), ACCURACY INTERNATIONAL, BERGARA, HOWA 1500, & RUGER RPR

A relatively frequent complaint with M700 and Accuracy International actions (and others) are cratered primers with factory made ammunition. The root cause of this is from excessive clearance between the striker and the hole through the bolt face. When fired, the primer cup flows into the void...

www.longriflesinc.com

Chad at LRI is one of the best

Good looking out. That's cheaper than buying another 3-5 hundred pieces of brass and time for primers.

Will be calling him tomorrow AM.

 

[diggler1833]

Maybe time to get the firing pin bushed if it happens with SRP. Blanking primers like that without other pressure signs is usually pretty indicative of the need.

Fortunately, many good gunsmiths offer that service for relatively little money and quick turnaround with nothing more than your bolt needing to be shipped off. I know Matt Stewart does it in my neck of the woods, and he'll only remove .0005 - .001 off your bolt face so you don't have to mess with headspace. Here's another place:

Firing Pin Bushing

beanlandrifles.com

Here's a video on it by Greg Tannel. Greg is a heck of a guy, and I've spoken with him many times and use his Remington 700 firing pin assemblies.

 

[swampratt]

I have some CCI 450's you can try and I also have some 210M if you want those I will trade you out if you get me some CCI 200's Even Steven.

I have read the 7 1/2's will crater like that and the CCI 450 will not.
Those Remingtons are just soft.
I did some testing on the small primers the CCI 400, 550 and 450 and the 400 would crater and pierce a hole and the 550 would be a smaller crater but never a hole and the 450 just about zero crater.

This was a an over pressure load just for testing cup toughness in a .223 case.

PM me

 

[Letfreedomring]

Before bushed firing pin on my ar-10 with a Uintah Precision upper:

Then after with same load and probably around the same temp:

Edit: I used this guy which did great work at a reasonable price, but backlog was pretty high around the covid lock downs:

Bolt Bushing Service

***Turn around times currently 5 WEEKS, I'll update this as it changes*** Are you having issues with primer crating??? Bolt bushing will solve your problems. Cratering is caused when you have a firing pin poorly fitted to its pin hole, the larger diameter of the pin hole also contributes to...

adarmscustomrifles.com

If I remember right these are S&B LRPs