My exact findings, firing a Savage Axis in 223, as rifle came from the factory. The 7 1/2 fixed it.Someone else reponded it was the CCI400 primers being too soft. So I tried some Remington 7 1/2 and it went away.
Still shooting the same lot of CCI400s. They are not piercing, blanking or venting any gas. Just look bad.
Don't know that is is the best solution but for now I just found 1k CCI450 so I will shoot the season league and then tackle this again. League is 10 weeks and 25 rounds per week. 20 on target and 5 foulers/sighters.
Funny how most everybody wants you to throw $$$$ at it, especially if it isn't there's.
First thing I would do is check the headspace of the brass. (NOT THE CHAMBER HEADSPAVCE)
Said it bunch of times but it has to involve $$$ to fix the problem??
Brass too short for the chamber. Shoulders pushed back too far, firing pin pushed case forward in the chamber, (we're only talking a few .000) round fires, primer tries to back out of the pocket, case blows back against the bolt head, primer gets "blanked/punched/cratered"
Easy fix it to increase the OAL of the case by loading your bullets to a jam, fire the round and the shoulder gets blown forward.
And with that, it hasn't cost you a dime. (problem solved)
And NO, I don't know everything but I've been there, had that same problem, corrected it without spending a dime! It IS a learning process.
Oz never gave nothing to the Tin Man, that he didn't already have.
That’s not the problem. We’ve already isolated the cause & repair. Shoulder bumped back too far is much more likely to supper light primer strikes, not cratering/blanking. Nobody is telling him to spend needless money. In fact, the very first thing I said was bring the pin to shorter protrusion & make certain the radius is correct. I know I am, and at least a couple others are simply giving him the correct information.
Have already played with head spacing and case length using a number of different gauges to no avail.Originally Posted by Nor Cal Mikie
To restate, I am aware that using the 450 primers is only a band-aide and not a cure.
For now I am going to look for a good workable load and then have fun shooting this winter league again.
Just a thought. Since the primers are good in the M11 with the same barrel, you move the barrel to the M10 and the primers are messed up. Try using the M11 bolt in the in the M10 and see how that goes. Check headspace. Also has the M10 bolt head ever been changed. Is the hole for the older larger firing pin? Some pictures would make a huge difference.
The Dunning-Kruger effect is alive and well.
He did change the Bolt Head Robin. His first post he said he replaced the BH with one from Gun Shack. And also his pin protrusion is .056”. But he said the radius looks ok. My post#11, I indicated it’s a case of a bit too much. Meaning a little bit too much protrusion, a little bit too much slop in bolt, etc. Switching the bolt heads ain’t a bad idea. He said it started after swapping the bolt head, so that is almost assuredly the problem.
FWIW, my .223 Axis cratered primers from the first to the last shot it fired, over 4000 rounds. Factory, reduced loads and max loads all the same. Never pierced a primer, just a small crater. My model 12 does it as well, just not as much. I've had it happen in several other guns I have owned, most recently the HK VP9.
Im sorry if I made things confusing. He stated that the same barrel fired in another rifle he had produces no cratering. He moves the barrel to a different rifle and he gets cratering. Proof he has an issue with the firing pin and Bolt Head he is using in the problem rifle, is verified by switching the bolt over from the rifle with no issues. The process of elimination is my point. From there you fix the protrusion. Then you measure your firing pin and your firing pin hole, inspect the intersection of the firing pin/bolt face to determine if the radius is to long. My point was that he has examples of components that work. What is different? Measure, observe, test conclude Protrusion at ignition is the only length that matters in this scenario. If you have .075" protrusion with the bolt out of the rifle it really does nothing to impact your primers and cratering. It only shortens the approximately .250" of firing pin travel .050 +or-(There is a hidden gem in firing pin travel if you know what you are looking for). If the firing pin has moved far enough to ignite the primer it probably will not be any further than .025" protrusion beyond the face of the bolt head. The firing pin stop will not impact the base of the bolt head for max protrusion with a case and primer in the chamber. That is of coarse if your case is sized correctly and not sitting down in the breach below proper case protrusion.. This is really a very simple to identify and fix if the OP has good guidance, follows basic trouble shooting practices and verifies before moving to the next step. Sometimes people will pass over things if they don't understand or the information was not clear. When you have multiple concepts combined with irrelevant data it can get confusing.(Think Dale Carnegie)
The Dunning-Kruger effect is alive and well.
Just to clarify but this is exactly backwards. The primers cratered in the model 11 but not the model 10.
Is it a safe practice to move the bolt from one receiver to another?
I truly have tried to take some pictures of this but my camera doesn't focus in close enough.
It is safe but you check the headspace. The bolthead may have some slightly different dimensions and it may be fine but always check.
The Dunning-Kruger effect is alive and well.
Follow these rules with firing pins and you won't have a problem caused by the firing pin. I've lived by this for many years and it works. This is the correct way to set up a firing pin. Pay attention to the difference between small and large rifle primers. This is exactly what you've changed.
Watch the 2nd video and pay close attention to the "rules"! It can get a bit confusing, so have a paper and pencil to write the info down.
Firing pin design and fit (video mini lesson) - AGI Gunsmiths (milsurps.com)
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