Hole in primer after firing (UPDATE 9/18/11)

[NorCalMikie]

Hole in primer after firing

I don't think anyone was calling a comparator a "headspace gauge". The comparator does just that. It compares the case shoulder measurement to the actual length of the chamber.
Izrua mentioned only firing a few rounds of new factory ammo that hadn't been fireformed to his chamber.
Until the cause is found out otherwise, IMHO, I'am still thinking that the unfired cases were too short for the chamber. "Actual" headspace "could" be adjusted a little on the tighter side with no ill effects. Only problem would be not being able to fire factory loaded ammo. Again, not a bad thing unless you don't reload.

 

[fguffey]

Hole in primer after firing

"Izrua,
Welcome to the forum, I as well believe you have a head space problem, if I had a suggestion for you I would just cut and paste NorCalMikie's post as I believe he is spot on.
Wayne."

I am not looking for immediate neighbor hood acceptance, If I do not agree, I do not agree, after you say "+ ONE" or "I believe he is spot on" you have two choices, in my opinion you chose the typical, expected, predictable choice, I would have been surprised if I had said something that would have provoked you to think.

F. Guffey

 

[bozo699]

Hole in primer after firing

Are you by chance related to Big Ed?
Wayne.

 

[NorCalMikie]

Hole in primer after firing

And I might add, right off the bat, everyone wants to blame it on the rifle. Mechnical defects. Weak firing pin spring" ? Bolt face needs to be bushed? KISS!
First place to start is the ammo that was fired. Was the OAL of the case too short? CHECK THE AMMO!
If it's mechanical problems with the rifles, all 5 of my Savage rigs are bad because over time, each and everyone of them has pierced a primer or two. And it has come down to the case being too short for the chamber and when the round was fired (by the weak firing pin spring ???) the primer got pushed slightly out of the pocket and the firing pin punched a hole in it.
Longer case OAL corrected that problem. And I didn't have to replace the "weak" firing pin spring or bush the bolt head.

 

[fguffey]

Hole in primer after firing

"I don't think anyone was calling a comparator a "headspace gauge"

I said the standard answer is "Purchase a comparator from so and so" and then I said "Forgive" '" 'Ole' so and so calls his comparator a head space gage" and then I added the "HUH" symbol.

F. Guffey

 

[NorCalMikie]

Hole in primer after firing

It'll be real interesting to see what the "real" problem turns out to be? I could be wrong but I've had the same thing happen to me and it was ammo related.

 

[fguffey]

Hole in primer after firing

"Are you by chance related to Big Ed?"

In defence of Big Ed? There are three I know of, one is in Kansas City, he is OK, problem, he does not answer the phone, no longer in service and he does not respond to email.

In my opinion there is one of the three that goes way out of his way to make himself look good at others expense, I understand conseat, big ego personalities that are self centered, in my opinion he can not help it.

I am impressed you and I agree, I have no ideal why you suggested I excluded anyone from the conversation.

Again, forgive.

F. Guffey

 

[Izrua]

UPDATE(9/18/11): Readjusted the headspace (tightened). Fired 13 rounds (factory ammo, Norma brand, 6mm Norma BR).
11 rounds have severe cratering on the primer, 2 rounds have a pierced primer.

The 4th round and the 9th round are pierced. The piercing looks different than the previous occurrences, you can see what looks like a pin strike on the 'bar' inside the case.

 

[NorCalMikie]

Do you reload? Can you reload those cases that have been fireformed to that chamber? The "factory ammo" may still be too short for that chamber. Any way for you to know if the bullets were jammed into the lands?
How did you reset the headspace? What did you use for a go/ no go gauge?

 

[NorCalMikie]

The reason I asked if you knew if the bullet was jammed or jumped to the lands...From what I've experienced in my 6BR rigs, if the bullet has a jump to the lands you could start showing pressure signs but, that same load with the bullet jammed maybe .010 "into" the lands, you'll show no pressure signs and can even go up in powder charge before you start seeing pressure. Like I said, "my rigs". YMMV, Mike.

And something else to check. Is the lettering on the case head face smeared? That would be a real good indicator of excessive pressure. Hard bolt lift? And other signs of over pressure? Case hard to extract? Lots of questions.

 

[fguffey]

"The "factory ammo" may still be too short for that chamber"

Just a thought, if the pressures increases does the firing pin spring need more pressure? If we are reloaders and reloading for a chamber, why don’t we know the length of the chamber first? I form first then fire, others fire to form, difference in methods and techniques? Out side of reloaders, industry, any industry when punching a hole in metal a back-up is used to punch a hole , especially metal as thin as a primer. But, this is reloading.

F. Guffey

 

[NorCalMikie]

Well, lets put it this way."I" have never seen a weak firing pin spring. If you keep thinking a "weak spring", then maybe they're out there? We don't know how old the Savage is that he's working with. And we don't know "how much" he knows about reloading and the rifle he's working with.
My suggestions are baised on my experience with "my" Savage rifles and the problems I've come up with while working with the 6BR.
Punches a few holes in primers and 99% of the time it came back to a brass problem. That's the reason I asked more questions.
How did he set the headspace? How old is the rifle? Could it "actually" have a weak firing pin spring? Can he reload those formed cases and see if it still pierces primers? Was there any pressure signs visable on the case head?
We're standing on the outside, looking in and trying to sort out his problem. Maybe we need to make a "house/range call? ;D

 

[GrocMax]

As a data point I always set my Savage's firing pin protrusion to .035"-.045" and have never ever ever seen a pierced primer (or a misfire related to primer strike), even on brass sized smaller than it needed to be. And we're talking ejector swiping, totally flat primer, loose primer pocket, ruin a case loads on occasion during load dev.

A pin that travels farther than it needs to may be a contributing factor, and adjusting it is a snap (if you have nice strong fingers), remove the firing pin assy from the bolt, hold the rear of the pin on a table, vise or whatever, compress the spring down slightly so the lock plate is away from the notches of the retainer nut, rotate the retaining nut counterclockwise when viewed from pin end one notch, this should reduce protrusion by ~.015". Reassemble, test.

 

[butchlambert]

I have hesitated to post on this. I did have a weak firing pin spring about 8 yrs ago that did the same thing. Changed the spring and the problem went away.
Butch

 

[fguffey]

Butch, 2 weeks ago three friends went to the range with their new creations, repairs and builds, not a shabby bunch 2 are master machinist with 110 years in the trade, all three have a total of 150 years in the gun smith trade, and it goes without saying they load their own, one took a 'BAG', 50 BMG chambered single shot, He chambered 5 rounds and got nothing but a big CLICK! with varying small dents. The next day after returning from the range he called me, most if not all on this forum would have been insulted had I ask them the questions I ask my friend, he answered every question, he ask me for help, I gave him the good news, the rifle has a life time warranty and the business changed names but still in business then I furnished the contact information.
The next day I went for a visit and checked the parts that were not shipped back. Some would wonder with all that experience at the range there would not be enough room for all the hands and minds trying to get into the chamber, that did not happen, nothing was said about datums, head space or the effect the case would have on the chamber when fired.

The builder of the rifle said the owner of the rifle had a very bad habit, he said the problem is very common with owners/shooter that leave their rifle cocked after the last firing, my friend was instructed to send the bolt back. And I asked more questions, the M-2 barrel had been replaced with the other BMG barrel and a different brake was made for it. My friend made drawings, after looking at his drawings I ask him about the gap between the bolt face and head of the case, he replied with "There is no gap and or space between the bolt face and the head of the case" I took his shell holder from his press and inserted a case and ask him "Like this" and the answer was "Yes", then he explained to me how he head space the barrel to the action, and I said "You head spaced the chamber twice", my friend is brilliant and the builder of the rifle is as brilliant, by pinning the case head to the front of the bolt the case head was head spaced to .000 with .000 clearance between the shoulder of the case and shoulder of the chamber.

And I informed my friend time is a factor, with new ammo and .000 clearance the time factor is reduced to the case filling the chamber (outward) before it gets serious.

F. Guffey

 

[NorCalMikie]

Butch: I could see why you were hesitant about getting into this discussion. No one has "thrown blows" yet so I think we're still OK. Still too many unanswered questions.
Too much firing pin protrusion? Weak spring? Cases loose in the chamber?
Be real interesting to see the final solution. I've still got questions. Why isn't the piercing consistant? If the firing pin is weak, why doesn't it pierce all the time? Crud in the bolt body?
Is the rifle new or have a lot of round through it? I've had pierced primers from short brass and after fireforming, it went away. That's where I'am coming from. The short case gets pushed forward by the firing pin and sometimes won't pop the primer. When the short case gets fired, the case isn't tight against the bolt head, the primer can get pushed out of the pocket, gets pierced by the firing pin then gets pushed back in place. The primer isn't flattened or show any pressure signs. Everybody starts off thinking mechanical problems with the rifle? I woke up this morning thinking about this so I need an answer. : Still more questions than answers, Mike.

 

[fguffey]

"I could see why you were hesitant about getting into this discussion"

It is possible Butch is hesitant about getting into this conversation because he does not think he has the luxury of disagreeing, or does not want to defend his position, I suppose you missed the part where the manufacture said some shooters of his rifles have bad habits, they leave his guns cocked.


"When the short case gets fired, the case isn't tight against the bolt head, the primer can get pushed out of the pocket, gets pierc by the firing pin then gets pushed back in place" That does not happen.

Not on my rifles, the firing pin crushes the primer before the case, bullet and powder know, their little buddy, the primer has been crushed, I know the total knowledge of what happens between trigger pull and the bullet leaving the barrel is posted on reloading forms looks like a demonstration/cartoon, and not one time does it mention time as being a factor.

As I said before the firing pin crushes the primer by putting a large dent it it, the dent size is reduced when the pressure inside the case/primer form the primer to the shape of the protruding firing pin, not on your rifle but on my rifles if the spring is too week to prevent the pressure inside the case/primer from pushing the firing pin back a hole is cut into the primer by the escaping hot high pressure metal cutting gas, and I gave a qualifier, hot high pressure metal cutting gas escaping through the hole in the primer will be supported by the firing pin, and the hole in the bolt face is a 'back up' instead of punching a hole, the hole is punched by high pressure.

The other qualifier was the hot, high pressure metal cutting escaping around the primer when it is unseated would be evident with a ring on the face of the bolt the same size as the primer, I could say 'think about it' I am a reloader, I determine the length of the chamber first then I form cases to fit.

F. Guffey

The primer, case, bullet and powder accelerates to a speed equal to the speed of the firing pin, THEN! the shoulder of the case hits the shoulder of the chamber then the primer is hit ????? by the firing pin??? Not on my rifles.

 

[butchlambert]

I don't have a position to defend. It was suggested by Cecil Tucker that a weak spring may be the culprit. It was easy to change. The old spring had 14# pressure. The new one is 22#. My bolts are never in my BR rifles unless I'm on the firing line after the commence fire.
I don't have a clue as to why the OP is having a problem.
Butch

 

[bozo699]

I don't have a position to defend. It was suggested by Cecil Tucker that a weak spring may be the culprit. It was easy to change. The old spring had 14# pressure. The new one is 22#. My bolts are never in my BR rifles unless I'm on the firing line after the commence fire.
I don't have a clue as to why the OP is having a problem.
Butch

No and none of the rest of us know for sure either, except of course for Ed. Were all soooo dumb and he's soooo smart : terrible situation.

Mike you said something I had forgot about, probably not the problem but,.....I had a old Savage bolt action 3030, it would fire about 1/2 the time, I had my smith check firing pin protrusion, it was right at .060, he reset the head space although it was well within specs he said, problem still persisted, even worse when I reloaded, never did figure that one out? anyway gave up on it and put it away, a few years later another good friend of mine also a gunsmith made mention he had a disabled friend that he was looking for a short carbine so he could poke it out either window of his pickup, I told him about my old 3030 and he said let me have a look at it,.................crud in the bolt body was all it was. I gave that rifle to my gunsmiths friend , which is now a very good friend of mine and a very happy disabled hunter that has taken several deer/elk,and bear with that old carbine,...just a thought.
Wayne.

 

[fguffey]

"except of course for Ed"

Bozo699, Who is Ed?

F. Guffey