223 cratering primers

[Nor Cal Mikie]

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.

[Dave Hoback]

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.

[KMW1954]

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".

Have already played with head spacing and case length using a number of different gauges to no avail.

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.

[Robinhood]

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.

[Dave Hoback]

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.

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.

[charlie b]

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.

[Dave Hoback]

I agree it’s not the worst thing in world… However, it’s not a good thing either. And as we’ve discussed several times in the past, there is always a cause. I believe it’s one item that also which can contribute to poor accuracy. If the accuracy is good, and the added stress on components is of no great concern, I guess there’s no harm in it.

[wbm]

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.

Same here.

[Robinhood]

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.

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)

[Dave Hoback]

No argument here.. Could not have said it better.

[KMW1954]

Sorry for not being involved here for a short time but have been distracted with working extra hours at the range getting ready for opining of Wisconsin Deer gun season. The accident with the blown up BP Rifle and then an emergency with a child.

So there is still some confusion revolving around the gun barrel and the ammo.

Have not changed any barrel yet but the thought and question is there. I believe the confusion is that this load has been fired in two different guns. The model 11 that this is supposed to be for and is showing the cratering. As a test I have also fired this load in my model 10 which shows no signs of cratering. Which lent the question of swapping the barrel from the Model 11 to the model 10. The model 11 barrel is new this fall while the model 10 is getting weak and the groups are opening up..

I have been hesitant in just swapping bolts from one receiver to another and feel more comfortable swapping barrels. Feel the bolt and head has already been seating and worn-in to the receiver on the Model 10 rifle.

Robinhood you lost me with the "hidden gem". Yes I am convinced that the problem lies with the firing pin and the pin hole in the bolt head. I just don't know the ins'n outs of this subject yet and also do not feel I have the proper tools to measure or do the work. But with all of you and your help I am learning. Just hoping you all keep patience with me.

[KMW1954]

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.

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.

[Robinhood]

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.

[KMW1954]

It is safe but you check the headspace. The bolthead may have some slightly different dimensions and it may be fine but always check.

Thank you so very much. That is quite reassuring.

[Dave Hoback]

Yerp… swap bolt heads as you like. Just always check headspace. One of the wonderful things in the world of Savage. They have a certain consistency not found in other rifles. Much the same as say, the AR15 platform. One bolt can fit many different rifles, and still provide for exceptional accuracy due to its design. Of course some will fit better than others.

[Rflshootr]

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)