Failure to fire question

[mdevlin53]

I have been working on a load for my 10.5x47r its a 45-70 case cut back an 1/8th of an inch and necked to accept a .430 Boolit. I usually load about 20 rounds and go see how they work. Each time i have gone out i have at least one round that fails to fire. I used CCI benchresr, Federal Large rifle and recently a batch of magnum primers. Each time the Primer is well dented so it is not a firing pin problem. I wait a while and give the round a quarter turn an try it again ond no good. Any ideas I have heard of a paper wad over the primer but i dont know enough about it yet. I did not have a similar issue with the 38-55 rounds i loaded with the same powder. In both cases it was Goex 2ff.

[Dan Cash]

Without examining your gun or ammunition, may I offer the following probable causes?
. Primer not fully seated (Are you using pistol primers)?
. Primer has oil contamination which "killed" it
. Gun has very excessive headspace

You can easily check/correct for the first two by ensuring the primer is flush with the base of the case and not handling the primer with fingers. If using pistol primers, your firing pin may be too short. Discontinue use.

There are different ways of checking for and overcoming excessive headspace depending upon your gun. You probably should consult a gunsmith.

Not a lot of help here but hope you resolve the failure to fire problem.

[mdevlin53]

On the last batch i made sure that each primer was seated flush not tot far out not too far in. I try to keep oil away from the cleaned rcartridges so i dont think that is it. At work we use a thing called plastiguage for determining clearance in bearing fits , I might be able to get some and see if there is an excessive gap between the cartridge base and the bolt face. I am using large rifle primers.

[swheeler]

On the last batch i made sure that each primer was seated flush not tot far out not too far in. I try to keep oil away from the cleaned rcartridges so i dont think that is it. At work we use a thing called plastiguage for determining clearance in bearing fits , I might be able to get some and see if there is an excessive gap between the cartridge base and the bolt face. I am using large rifle primers.

Primers need to be seated until they bottom out in the primer pocket, if not the energy from the striker is wasted on seating the primer and may not ignite the primer charge. Run your finger tip over any factory loaded round, primers are not flush but actually seated to bottom of primer pocket, which is below flush.

[oneokie]

Some questions. Are you using the same batch of cases for each loading? Do you break down the ones that fail to fire and reprime and charge them? You may have a case/s that have deeper than normal primer pockets. Mark the cases that fail to fire someway that you can use to determine if it is the same case/s time after time.

[oldracer]

The things Dan mentioned are pretty much what can cause the mis-fires. I had this happen with a S&W model 327 TRR8 and had to get an aftermarket firing pin because even though the primer would dent it was not quite enough. I would suggest making sure the flash holes are all the same size and I drilled my 45-70 cases just to be sure. Some brands of brass were way too small. I also cleaned the inside of the flash hole and put a small bevel inside.

I would suggest measuring the primer thickness and the depth of the hole to make sure that the primer is not moving inward on a firing pin strike. You could also try another brand of primers, I have been using Winchester standards for all my loads and have had no primer related issues.

Finally, try cleaning the cases very well and then inserting a primer, looking inside with a strong light and you should be able to see the primer through the flash hole. Try firing just the primer and look at the inside of the case to see the blackening and if they are all the same.

[mdevlin53]

I think i am going to take a close look at the primer holes. and mark the failed rounds like you mentioned. It is just weird because it happens 1 out of twenty times but it is the same batch of cases so i could have a bad one or two.

[405]

Primers need to be seated until they bottom out in the primer pocket, if not the energy from the striker is wasted on seating the primer and may not ignite the primer charge. Run your finger tip over any factory loaded round, primers are not flush but actually seated to bottom of primer pocket, which is below flush.


That'd be my guess also. Add that to a little extra headspace and no fire.

[waksupi]

Your primer seating is the problem. As was said, they need to be bottomed out. CCI is known for this. I contacted them some years about FTF as you are experiencing. They said that the rims of their primers are cut more sharply than most other brands, and firm pressure must be used in seating them completely. After I had that bit of information, I had no more failures to fire. The way you are seating them, they need the first firing pin strike, or more, impulse of the firing pin strike to drive them forward enough to ignite with the primer anvil.

[Don McDowell]

I'm going to guess with the primer not seated deep enough crowd, altho I'ld mark the ftf case, for future reference.
I'ld also check the rim thickness of that case to be sure it's not a thin rim induced headspace problem.

[John Boy]

Here's where you start finding the answer ...


Primers have to be hit fast and hard. One without the other is useless.

With the primers being ... "Each time the Primer is well dented" - (hard) sounds like the speed the firing pin is hitting the primer is the possible issue. Might want to start with a cleaning job

[mdevlin53]

I guess i shoud have said the firing pin mark on the cases is cosistant from both the cases that fired and failed cases. it is not overly deep. I am going to review my loading procedure and see if there is anything i need to change or correct. I use a spray case sizing lube and i will run some alchol on a swab after the sizing, I dont use much but perhaps this could be an issue, more attention to the holes, and swat the primers all the way. I am using remington brass and i do notice some primers seat fairly easy and some are a bit tighter. The ke to cosistanct is doing it the richr way each time so like i said review each step and then mark the bad boys and see whats going on.

Thanks for all the advice i cant tell you how good it is to have all this experience at yout fingertips.

[405]

I also agree with the posts about pin hit. Have seen it more than once- especially with milsurps or guns that have been in storage. Gunk or grease in the bolt body. Wouldn't hurt to take the bolt apart and do a thorough clean. As to the primer seating I've also seen primer pockets mis-matched in size to the primer- where either the primer is a tad large or the pocket is a tad small. Remington regular LRPs seem to be fairly soft and can be seated in tight pockets using some discretionary force. The second choice would be to ream or swage the pockets. Various tools are out there for that but it would be a second choice for obvious reasons.

Of course other possibilities could include a broken pin, weak spring or short pin tip.

[Good Cheer]

I have been working on a load for my 10.5x47r its a 45-70 case cut back an 1/8th of an inch and necked to accept a .430 Boolit. I usually load about 20 rounds and go see how they work. Each time i have gone out i have at least one round that fails to fire. I used CCI benchresr, Federal Large rifle and recently a batch of magnum primers. Each time the Primer is well dented so it is not a firing pin problem. I wait a while and give the round a quarter turn an try it again ond no good. Any ideas I have heard of a paper wad over the primer but i dont know enough about it yet. I did not have a similar issue with the 38-55 rounds i loaded with the same powder. In both cases it was Goex 2ff.

In old and worn rifles there is a remedy I have used with success. Little paper punch round from manila folder seated in the primer pockets with an allen wrench and the primer seated on top. All I can say is "Works for me".

[mdevlin53]

Now that an idea i had not heard of, Do you punch a hole in it? or was that a dumb question

[Good Cheer]

No hole. The center of the paste board blows through. I'm doing that on Bertram brass and it gives just enough "umph" to make it go bang every time.

[montana_charlie]

I have nothing to add to the suggestions above. They cover all of the possibilities I can think of, considering the amount of available information.

It might inspire new possibilities if we knew the action type of the rifle in question, and whether it is new ... or an antique.

CM

[mdevlin53]

I guess i should have added that, Its a bolt action and from the late 1800 or early 1900s. I did a quick check on the headspace and it is pretty tight less than 10 thousands. I re-cleaned the cases and later today i am going to load them up and pay close attention to each step and see if i can find a flow in the process then when i shot them i will keep track of ow each one performs.

Good Cheer, what do you use to punch the little paper rounds?

[montana_charlie]

I guess i should have added that, Its a bolt action and from the late 1800 or early 1900s.
Antique bolt action ...

The firing pin may not be quite as long as it was when new, or there may be something foreign inside the bolt that prevents full travel.
Have you measured the maximum protrusion from the bolt face?


Using narrow strips of 'primer wad paper' slipped between the case head and the primer can 'cookie cut' discs into the primer pocket as the primer is seated.
The heaviest paper I have heard of being used is kid's 'construction paper'.
I don't know if a primer will cut manila folder stock.

CM

[Red River Rick]

What make and model?

That "less than 10 thousands" is still excesive for head space. The problem could be a combination of that and what MC has mentioned.

RRR

[mdevlin53]

The less than 10 thousands is just a rough check i need to get some plastiguage to check it for sure. I has a sheet of paper that was .010 and the bolt would close on an empty case but you could feel it was tight. i will check it again when i get the guage. As for make and modle it is german and after the Mauser 1871 pattern.