Excessive primer dimpling with CCI 450s.

[Rsadams]

Upon confirmation with my wife, she noted that the primers used in her 17 hornet loads are from the same case and that they in fact crater similarly with her loads. Perhaps it is a soft lot of primers?

If their CCI small rifle they will flatten etc at a very low to medium charge... I use them in my AR and it flattens them but any other primer is fine... It will be fine , I have a savage that does the same... Alot of factory guns do it... I personally wouldn't worry about it...

 

[Pawnee Bill]

Carlsbad is your Bolt Bushing Guy ..............
Look Him up on this site.
great work .

Send you bolts to Carlsbad, no more cratered primers. As easy as that!

 

[BlackGrouper]

Normal for my factory Savage bolt faces.
25-06 with older CCI 250's from early 90's

 

[CharlieNC]

You WILL eventually need to adjust protrusion and replace the firing pin spring, and it's wise to keep a replacement assembly in your range box. Also PTG makes a nice bolt head that corrects the dimpling, Brownells used to sell them.

 

[BlackGrouper]

You WILL eventually need to adjust protrusion and replace the firing pin spring, and it's wise to keep a replacement assembly in your range box. Also PTG makes a nice bolt head that corrects the dimpling, Brownells used to sell them.

Yes, PTG part works well, this is 46gn Varget w/ 155.5 Berger BR2 load using factory firing pin and their bolt face.

 

[JFrank]

So, I recently bought a lightly used 6BRA barrel of a fellow forum member, and installed it on a Savage action..... The action was originally a 308 Winchester.... During load work up, based loosely on the barrels previous owners data, I have been experiencing very excessive primer cratering with CCI 450 primers. All loads are below the previous owners max loads ( example: 29.7 gr. Varget under a 108 ELD-M versus his 31.5 gr. Varget load). My question is, this..... If there are no signs of pressure issues ie. no stuff bolt lift, cases measure well within the specifications for the 6BRA, no extractor swipe etc, could it be a firing pin issue( either loose firing pin, firing pin spring to heavy) or possibly a soft lot of primers. When the rifle was a 308 there was never an issue with dimpled or cratered primers at near max loads.... I find it difficult to believe that there would be an issue now from a loose firing pin. What I'm wondering is if the firing pin spring itself might simply be to strong. Small rifle primers have a cup thickness of .025( on average, not all), but all large rifle primers have a cup thickness of .027. Could the issue be that Savage uses a stiffer spring in rifles intended to use large rifle primers? Anyone have any experience with this particular issue? Let me know what you all think?

I’ve seen this dimpling on a custom action as well, I would check your headspace.

 

[titus123]

I’ve seen this dimpling on a custom action as well, I would check your headspace.

Headspace is good. Firing pin fit, not so much

 

[FNSafari]

I’ve seen this dimpling on a custom action as well, I would check your headspace.

Was that due to an action problem or a poorly fitted barrel?

 

[JFrank]

Was that due to an action problem or a poorly fitted barrel?

Iirc I had a touch more headspace than I needed in that brass but after a die adjustment It stopped although now that I mentioned it’ll probably surface again.
just my luck..

 

[NorCalMikie]

Everybody blames the firing pin and the bolt head needs to be bushed!!! SOP!! Throw more $$$ at it. That'l fix it!


Owning a "few" Savage rifles, I look at it a different way. KISS!!
Where did the brass come from?
New, used? Fire formed to THAT chamber?
Looks to me like maybe the head space is off "just a little". (more of a brass issue than chamber issue. remember, it's a Savage)
The brass can move in the chamber, firing pin hits the primer and pushes the case forward in the chamber, primer goes BANG and tries to back out of the pocket "a bit", gets slammed back onto the firing pin and gets cratered.
Once brass is formed to "that chamber", when resizing, make sure you don't push the shoulders back too far and end up with the same situation again.

 

[titus123]

Everybody blames the firing pin and the bolt head needs to be bushed!!! SOP!! Throw more $$$ at it. That'l fix it!


Owning a "few" Savage rifles, I look at it a different way. KISS!!
Where did the brass come from?
New, used? Fire formed to THAT chamber?
Looks to me like maybe the head space is off "just a little". (more of a brass issue than chamber issue. remember, it's a Savage)
The brass can move in the chamber, firing pin hits the primer and pushes the case forward in the chamber, primer goes BANG and tries to back out of the pocket "a bit", gets slammed back onto the firing pin and gets cratered.
Once brass is formed to "that chamber", when resizing, make sure you don't push the shoulders back too far and end up with the same situation again.

1. Brass is twice fired. Purchased new( Alpha munitions), and only every fired in this rifle.
2. Barrel was properly installed, and headspace.
3. Cases are sized full length, shoulders are set back .002.

 

[jackieschmidt]

It’s the firing pin hole, too much clearance.

You can try to convince yourself it isn’t, but it is.

 

[searcher]

If you head spaced your barrel several thousandths longer than prior owner did on his rig - the 'slop', combined with being a stiff load, will enable the brass to slap the face of the bolt - giving the impression of a hotter round.

 

[Old Navy]

It’s the firing pin hole, too much clearance.

You can try to convince yourself it isn’t, but it is.

Ditto! I have had one 700 and two Savages Model 12 BRs done. The problem will only get worst until your favorite load blows a primer.

 

[jackieschmidt]

Ditto! I have had one 700 and two Savages Model 12 BRs done. The problem will only get worst until your favorite load blows a primer.

I just did a 308 project with a brand new Remington 700. I did all of the usual improvements, ie trued the receiver threads and face, lapped the lugs, trued the bolt face, and sleeved the rear of the bolt,

it cratered primers with any load, that Irving pin to hole fit was way too much. The handle was not timed correctly, you actually had to lower it slightly to get the bolt to come back Upon extraction. The factory spring was all wadded up in the bolt ID.

Rather than mess with all of that, I just called Carlsbad and got a complete PTG Bolt assembly. All problems solved.
.

 

[Doom]

I just did a 308 project with a brand new Remington 700. I did all of the usual improvements, ie trued the receiver threads and face, lapped the lugs, trued the bolt face, and sleeved the rear of the bolt,

it cratered primers with any load, that Irving pin to hole fit was way too much. The handle was not timed correctly, you actually had to lower it slightly to get the bolt to come back Upon extraction. The factory spring was all wadded up in the bolt ID.

Rather than mess with all of that, I just called Carlsbad and got a complete PTG Bolt assembly. All problems solved.
.

Ditto the Rem 700. My 308 does the same. Primers are not always a good guide for pressure, especially cratering. If you don't normally crater and then crater then you have pressure.