Help Diagnosing Misfires

[WyleWD]

I don't recall seeing this posted and it's a long shot, BUT: have you pulled a bullet or two and looked to see if there is actually powder in there? Just sayin as I seem to load a cartridge sans powder every once in a while..

I am not the OP, but in my case yes I did. Priming compound in the bottom of the removed primer had not even tried to ignite in any of the dozen or so that FTF, and all cases out of both rifles had powder in them. Primers I have are stored in an area that I have a considerable number of primers and powder. No issues with other brands of primers. WD

 

[dkhunt14]

The OP isn't alone in this concern about BR4 primers. We have a pair of Stolle Pandas in 6br that we're getting FTF at about 4 out of 10 will not go off. Federal, Winchester, and Rem 7 1/2 all work fine. Headspace is fine, previously fired brass, bullets into the lands by ten thousandths.WD

Get a new firing pin spring. I have seen them get weak in two years. New ones are often 1/2 inch to one inch longer. Compression hurts them. I have seen a spring bring about better accuracy at long range. I replace my BAT springs every other year. Matt

 

[243winxb]

Is there any chance the firing pin strike itself was enough to move the shoulders back that much?

The first strike .006" set back. The 2nd strike total set back was .013" for my CCI 400 defective primer. Reset primer in different brass, it fired on the 4th pin strike. More testing showed the shoulder is always set back, using a fired primer.

Shoulder set back will happen till the extractor stops forward movement of the empty brass, with a used primer installed. (SAVAGE 223 Axis)

Brass used, Black Hill Match , as it came from firing there ammo. No annealing. Head to datum gave a light crush fit in chamber.

 

[243winxb]

Primer seating -
I seat primers with an RCBS Ram Prime unit. I can feel the prime hit the bottom of the cup. Slight crush fit.

 

[scyzer]

The first strike .006" set back. The 2nd strike total set back was .013" for my CCI 400 defective primer. Reset primer in different brass, it fired on the 4th pin strike. More testing showed the shoulder is always set back, using a fired primer.

Shoulder set back will happen till the extractor stops forward movement of the empty brass, with a used primer installed. (SAVAGE 223 Axis)

Brass used, Black Hill Match , as it came from firing there ammo. No annealing. Head to datum gave a light crush fit in chamber.

Hmm - forgot to mention these were double strikes. In that case relative headspace might be inconclusive. I wonder if this also negates the primer marks themselves?

 

[WyleWD]

Get a new firing pin spring. I have seen them get weak in two years. New ones are often 1/2 inch to one inch longer. Compression hurts them. I have seen a spring bring about better accuracy at long range. I replace my BAT springs every other year. Matt

That's in the cue for problem solving on this. But since the problem of FTF is in TWO separate rifles, (one has a spring with only approx. 800 rounds fired), and both rifles fire Federal, Win, and Rem primers without any failures, I'm leaning more on this being a primer issue since it started immediately upon opening a new tray of 100 primers out of a box which has given a couple stray FTF on the first 300 used..... again 2 two different rifles, firing different makers of brass, and I had 2 FTF on a third rifle out of this and another (same lot of primers) box of 1000. My plan is to do another 20-25 rounds from each rifle with the other 3 makes of primers, then if they all fire I'll replace all of the trigger springs and try the BR4's again. And even if they work after changing the trigger spring (which I doubt they will predicated on the strong primer strikes on the FTF primers) I'll pitch the suspect primers and go to a whole new lot of the BR4's. I wouldn't even bring this to the net if it was only one rifle. Thanks for the input Matt. WD

 

[JLT]

Hmm - forgot to mention these were double strikes. In that case relative headspace might be inconclusive. I wonder if this also negates the primer marks themselves?

There's another thread on this forum dealing with the same thing - BR4s exhibiting a high FTF rate. It would appear that the circumstantial evidence clearly points to a problem with the primers themselves.

http://forum.accurateshooter.com/threads/cci-br-4-primers-failure-to-fire.3936976/

Try another primer. I'll bet the problem goes away. Given that the condition has been observed in more than one rifle and other primers have produced the correct outcome, I would defer on replacing parts like firing pin springs as that may be unnecessary.

 

[fguffey]

Savage actions - The firing pin strike can set the 223 shoulder back .006" The new brass will be stopped by the extractor.

I received a phone call, seems shooters were at the range mobbing up on R.P ammo, one shooter had purchased a new Rugger 30/06 with two boxes of 30/06 R.P ammo; he had 5 fail to fire out of a box of 20. The phone call had to do with, 'What is wrong with R.P ammo?' I instructed them to call R.P, the phone number was on the box.

Later that after noon the 15 fired and 5 failed to fire rounds show up here. The shooter allowed ever shooter at the range with a 30/06 to have a go at busting the primers. There were 3 shooters with 30/06 rifles, each shooter made two attempts ab busting the primers. The primers were struck at least 8 times each. If there was any truth to the firing pin shortening the case from the shoulder to the case head the failed to fire cases should have shortened .040"; that did not happen, I measured the length of all 20 cases and compared them with minimum length/full length sized cases. The cases were .005" shorter than a go-gage length chamber when compared to the distance from the shoulder to the bolt face.

We pulled the bullets and checked the components, we remove the primers and checked. we then installed the primers back into the case cases they were removed from and chambered them in one of my M1917. My M1917s have killer firing pins, one by one I busted the primers one by one, no powder, no bullet. What does that mean? My firing pin busted the primer before the case ever got o the shoulder of the chamber without the extra weight of the powder and bullet.

One more time: I measured the length of the cases from the shoulder to the case head, after busting the primers I measured the length of the case again, the cases did not shorten between the shoulder to the case head. Again, if there was any truth to your story about the case shortening .006" a reloader would not find it necessary to "BUMP" the shoulder back? .002" and then there is the small base die. If the firing pin shortens the case .006" what happens to the length of the case when the bolt slams the case into the chamber (try to keep up), to allow the bolt to close reloaders are using small base dies and going for full length sizing.

And I will bet you can not remember the first time you read the story about the firing pin shortening the case, I suggested he start that story with "Once upon a time..", or "You are not going to believe this" because I didn't and still don't.

F. Guffey

 

[JSH]

1917,1903,1903A3 have a heavy claw extractor. Which may in turn have held that brass back better than the others.
Have played with these rifles for quite a while, as you mention they are hard strikers on primers. Some of my soft play loads with cast bullets I have used large pistol
primers with no ill effects, along with some brass I was gifted from pull down WWII. Saved it from the scrap bin. Close to 500 of the. That had been sitting around for a long time.
Primers are a lot harder to kill than most think. I had some issues years back and I attribute it to fumes from bore cleaners.
Yet this past year I was reading on a discussion of killing primers. I had some junk stuff laying around and pulled it down and gave it a try. WD40, Kroil, Hoppes put a shot of some in several cartridges it did take a lot of the fire out of most. I let some set a while, wd40 never did kill completely. The other stuff worked better the longer it sat.

 

[fguffey]

In that case relative headspace might be inconclusive.

Head space? The case does not have head space. Again, I have killer firing pins, my firing pins crush the primer before the bullet, powder and case know their little buddy 'the primer' has been crushed. And then there is that boring story about the case outrunning the firing pin, not in my rifles.

F. Guffey

 

[mikecr]

It would take a great excess of striking force to bump shoulders with it.
Far more than needed for reliable ignition.

 

[JLT]

It would take a great excess of striking force to bump shoulders with it.
Far more than needed for reliable ignition.

Truth.

 

[Webster]

Thanks all for the help so far.

Tikka action - stock firing pin. Is there an easy way to measure protrusion of the firing pin? Currently thinking I'll measure the gap to the bolt face and deduct the gap to the firing pin from the front of the lugs.

The firing pin will always have enough protrusion. Firing pin protrusion is in the area of .045 - .060. This is more than enough to fire the primer. They should need no more than about 10 thou to fire them. There is nothing to stop it’s forward travel except the primer. Without a case in the chamber the disc behind the FP stops against the back flat side of the bolt face. Two flats come against each other. I don't believe in the so called hammer test. They are a sensitive explosive. Even if they are defective a hammer should set them off. Based on my experience I suspect pushing too hard. This may push the anvil into the primer charge reducing the how far the anvil can crush the charge. The primer charge disk make crack and lose sensitivity. Someone mentioned push till you feel it's seated then 2 thou more crush. Never heard this theory before. I would like to hear the source. Everything I read from Manufacturer says seat till the anvils touch the bottom of the pocket. Also some brands of primers don't have the anvils protruding out of the cup.

Never tried it, put some melted wax or clay in the primer pocket and see what the indent looks like.

A while back I saw a report that showed the standard test for primer sensitivity. Don't remember if it was a manufacturer or military. Great info I wish I could find it. They put the primer in a holder with something that duplicated a firing pin on top of it, then they drop a standard weight on top of the firing pin. They do a hundred of each brand of primers at various drop heights and record how many failed to go off at each height. The weight of the weight and the drop height can be converted to some unit of force. You end up with the minimum energy to set off 100% of the primers.

 

[Webster]

Head space? The case does not have head space. Again, I have killer firing pins, my firing pins crush the primer before the bullet, powder and case know their little buddy 'the primer' has been crushed. And then there is that boring story about the case outrunning the firing pin, not in my rifles.

F. Guffey

You imply that manufacturers don't know how much tension FP springs should have.

 

[fguffey]

It would take a great excess of striking force to bump shoulders with it.
Far more than needed for reliable ignition.

The first shooter that made up that story was asked about the chance he overlooked something, in the original story reloaders were lead to believe it was a race to the front of the chamber. I suggested the worst thing that could happen to a case is for the shoulder of the case to start out at the shoulder of the chamber; and he did not have a clue. And then I asked about the possibility of another event that that could cause the same problem.

F. Guffey

 

[Eddie Harren]

Not sure if this is fguffey or savagedasher!

 

[Someoldguy]

Not sure if this is fguffey or savagedasher!

Can't be fguffey. THIS man's appearance is too neat and his message too clear.

I've come to question if excessive head space is not a chronic condition for fguffey.

 

[Webster]

Can't be fguffey. THIS man's appearance is too neat and his message too clear.

I've come to question if excessive head space is not a chronic condition for fguffey.

Or zero headspace.