Primer Cratering

[deertroy1]

I have a Savage M11 with a McGowen 6mm Remington barrel. It craters primers with factory ammo and average pressure handloads. I contacted GreTan about bushing my bolt but he doesn't do bolts with one piece firing pins.

My question is:
Will a PTG replacement bolt head cure the cratering and do these bolt heads fit bolts with one piece firing pins?

[1vakid]

PM sent.

[Robinhood]

Have you measured the hole and the pin? Do you have a short throat?

[Zero333]

Copied from PT&G website....

"This Pacific Tool & Gauge Savage Bolt Head is a precision machined, drop-in replacement part for your Savage 10 or 110 Series rifle. Perfect for use in benchrest or F-class competition rifles that fire thousands of round per year, PTG's Savage bolt head is not subject to the quick deterioration or bolt face dishing that Savage factory bolt heads tend to display after a high volume of fire. The result is a drastic reduction in primer flow and case head rounding over time. Made in the USA"

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I'm sorry I have no first hand experience with this product.

I have a Rem700 in 223rem that always leaves craters in the primers no matter what. I don't find it to be any issue at all.
If you are getting primer blanking (piercing by the firing pin) then that's a different story.

With your handloads try CCI-200 / BR-2 or CCI#34 (hardest cup of all primers)

If you could post a picture of the cratered primers we might give you a better opinion.

Do google search for "PT&G bolt head reviews" to see what others experienced and if anything else could arise besides a straight swap and maybe resetting the headspace.

[Zero333]

http://bulletin.accurateshooter.com/2012/06/new-product-high-quality-ptg-bolt-heads-for-savage-bolts/

The link is to a small review that verifies the PT&G bolt heads cure primer flow issues.

[sharpshooter]

In most cases of cratering, the tip of the firing pin has to big of radius.

[BillPa]

Just to follow up on Fred's post above scroll down to my post here > http://www.savageshooters.com/showthread.php?24373-Cratering-Piercing-primers

Bill

[deertroy1]

I realize it's been awhile since I posted but I finally got a new PPG bolt head installed. Rifle is still cratering primers. I read another problem is firing pin protrusion. I measured mine and it is about 0.055" - 0.060". Could this be the problem?
My firing pin is one piece so how could I lessen the protrusion?

[charlie b]

I'd stop worrying about it and shoot more :)

My Axis in .223 has cratered primers since the first day I got it. Well over 2000 rounds now and it still does it. Not any worse than when new. No ill effects on rifle or brass. Still shoots better than I do :)

[olddav]

Firing pin protrusion article

https://www.savageshooters.com/content.php?143-Firing-Pin-Protrusion-Data

[Robinhood]

Excessive firing pin protrusion wastes firing pin travel. The firing pin will only extend about .020" when fired into a primed case. Once the anvil is driven into the bottom of the primer pocket it is done moving. I might look at excessive headspace or firing pin damage/fit.

[JW]

In most cases of cratering, the tip of the firing pin has to big of radius.


This
Thanks Fred

[tobnpr]

Softer primers will obviously be more susceptible to cratering, and a switch to a harder primer may help.
What are you using for primers?

Are your handloads delivering as expected- meaning velocity/charge weight? A chamber issue, unusually tight bore, and other factors I'm sure can cause higher than expected pressures.

If there's not excessive clearance in the FP hole, and primers aren't soft- I'd dig further. Determining whether you're actually overpressure isn't possible without a strain gauge- but cratered primers are still a reliable indicator of this, esp. if the mechanical clearances are good. Not something to be ignored IMHO.

[deertroy1]

The barrel is a McGowen prefit installed by a reputable gunsmith. I have gauges and headspace checks out good. Handloads have about 0.001" to 0.002" clearance. My loads are not max and velocities confirm as much. I've been loading for over thirty years but don't pretend to know at all. Primers used are Rem 9-1/2
Is there anyway to shorten the firing pin protrusion other than regrinding the tip of the firing pin. Something I'm not comfortable doing.

[Robinhood]

Honestly, I think you need to pay attention to sharpshooter.
https://lh3.googleusercontent.com/NQFSpyU9_jBFPN0BUF5h6lvTSaMkIp-E1wFFS-2NHZOHEqv3QKNqYQHqYvzAHDJaMKamMw=s113

[Nor Cal Mikie]

Beating a dead horse again BUT, ever consider the brass (on factory ammo) being too short for the chamber? Not a head space problem it's an ammo problem.
When the trigger gets pulled, the case gets pushed forward in the chamber by the firing pin, primer goes POP, rounds goes off and case gets pushed back onto the firing pin. Primer tries to move back out of the pocket, gets pushed back into the pocket and craters.
New bolt head, new contoured firing pin and you've STILL got the same problem? Hmmm. Keep throwing $$$ at it.
Keep at it till you find the right ammo OR learn to roll your own.
Like Charlie says "I'd stop worrying about it and shoot more".:cool:

[tobnpr]

Are you sure you're not jamming the bullet?
I would try backing off and increasing jump. You say you're not loading hot so seating a bit deeper into the case shouldn't be problematic.

[Texas10]

I bought a new Savage 223 that cratered and pierced any ammo I ran through it, light handloads too. I removed and measured the firing pin and it was quite undersized. Did your new bolt head come with a matching firing pin? I bought several new firing pins from Savage and cherry picked the one that fit best. That cured the cratering problem.

[charlie b]

If I was piercing primers I'd do something about it too. Mine just crater. I run near max loads with Varget and heavy bullets (69 and 77gn).

[GrenGuy]

Two things:
1. The link in post 10 tells all we need to know about setting FP protrusion.
2. You don’t have to “grind” the FP tip, You can simply take the point off it by rounding it on a sharpening stone, or emery cloth.
Best of Luck