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?
PM sent.
Have you measured the hole and the pin? Do you have a short throat?
http://bulletin.accurateshooter.com/...-savage-bolts/
The link is to a small review that verifies the PT&G bolt heads cure primer flow issues.
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"
--------------------------------------------------------------------------
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.
In most cases of cratering, the tip of the firing pin has to big of radius.
"As long as there's lead in the air....there's still hope.."
Originally Posted by sharpshooter
This
Thanks Fred
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.
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.
Honestly, I think you need to pay attention to sharpshooter.
The Dunning-Kruger effect is alive and well.
Just to follow up on Fred's post above scroll down to my post here > http://www.savageshooters.com/showth...ercing-primers
Bill
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?
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 :)
Most of my Savage rifles crater primers even with lower charges or with factory ammo.. At first I was concerned too but started to pay close attention to the “normal” crater look to see if it started changing indicating pressures are increasing. As pressure increases the crater will start to look different. So far so good.
I had to hunt, but I found the picture.
"As long as there's lead in the air....there's still hope.."
Firing pin protrusion article
https://www.savageshooters.com/conte...rotrusion-Data
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.
The Dunning-Kruger effect is alive and well.
Large radius will leave sharp edges. A smaller radius will blend into the shaft of the pin (I Think).
I'll try and make a sketch.
Is this what you mean:
So I made my firing pin look more like the photo on the right and it helped a lot with the cratering but didn't stop it entirely. I then made the firing pin a little more blunt but it failed to ignite the primers. I put it back more to what it is on the left and it fires okay but the cratering returned?
I also get really erratic velocities with this rifle (ES of 50 - 100fps is not uncommon). I've tried about everything I can think of but nothing works.
I then reviewed a diagram of the bolt assembly and noticed I had forgot to install a small ring between the firing pin spring and the bolt retainer spring. The spring has been missing for over a year but luckily I found it under my reloading bench and reinstalled it. I haven't had chance to shoot it since.
My question is: do you think the elimination of this little ring could be why my ES is so high?
On the radius of an ogive the larger the radius the pointier the tip.
"They couldn't hit an elephant at this distance." Last words of Gen. Sedgwik
I thought what you pictured is what I'm after. I'm sure a machinist/gunsmith could pull that off. Too bad I'm a carpenter! LOL!
High ES/SD was not reported in any of your prior posts, this is new information.
Usually, but not exclusively, high ES may be due to inconsistent ignition. You say you've "tried everything". I'm not familiar at all with the 6 Remington...but, did you change primers? Powders? What's your % of case fill? I think more info on current load data, and what you've tried prior, would be relevant in seeking a solution.
Did you check the headspace after installing the new bolt head?
Did you check the firing pin protrusion after installing the new bolt head?
Posting Permissions
Reply With Quote
Bookmarks