case lube and primer failure?

[JeffG]

Primers are so darn consistent these days, when two out of ten fail to fire I know I've done something wrong. Second chambering on both cartridges resulted in the same fail-to-fire.

This is a new wildcat build (hunting rifle, Savage 99), First thing I checked firing pin protrusion, nope, it was good. Maybe it was poor primer seating, nope, they're the same as the others, visually and with mics. This was my first round of case-forming, first ten shots through the rifle, maybe headspace was off, not likely with all chambering and headspace work done by a cometitive benchrest smith. What else?

What are the chances that still wet OneShot inside the brass corrupted my primer when I seated them? Maybe OneShot on my fingers when I handled the primers?

Any relative input will be welcomed, Thanks

 

[tonedaddy]

That is why, unlike most people here, I tumble my cases after sizing to get rid of all the lube crud. Not familiar with one shot but I use RCBS lube that is not oil based.

 

[ReedG]

Jeff, oily fingers will certainly contaminate primers, but chances of you having oily fingers on just these two cases twice in a row might be a bit far-fetched.

I would clean them well, keep my hands clean, and try again. If it they misfire again, you are probably looking at excess headspace. If they both failed to ignite twice, then if they have excess headspace it hasn't been blown out yet.

Just thinking ...

 

[Camaro80z]

What brand are they? I've been having a terrible time with 2 different lots of cci 250's. I can drive the firing pin through them and they will not light off.

 

[22BRGUY]

Did you uniform primer pockets...cutting the primer cup deeper? I did this and found out regardless of headspace and firing pin protrusion, my uniformed primer pockets were evidently too deep as when I left them alone I had no problem with Wolfs, whereas before, I had several non-fires. Best Wishes

 

[M-61]

Maybe I missed it but what case is this wildcat based on? Rimmed? Rimless?

 

[bigedp51]

JeffG

Take one of the cases that failed to fire and disassemble the round removing the bullet powder and primer.

Now measure the case length and write it down.

Next just using your fingers start a fired spent primer into the primer pocket with enough force to hold it in position.

Now chamber this test case and slowly close the bolt and let the bolt face seat the primer and then remove the case.

Next measure the case again checking to see how far the primer is protruding from the rear of the case and write it down.

Now subtract the first case measurement from the second and this will be your head clearance.

If your wildcat cases are on the short side, from shoulder to base your head clearance will be excessive and the cartridge may fail to fire.

Meaning you may have too much foam and not enough beer in your chamber for a good healthy shot.

Congratulations you now know how to make the cheap bastards headspace gauge (head clearance gauge) ;D

 

[22BRGUY]

JeffG

Take one of the cases that failed to fire and disassemble the round removing the bullet powder and primer.

Now measure the case length and write it down.

Next just using your fingers start a fired spent primer into the primer pocket with enough force to hold it in position.

Now chamber this test case and slowly close the bolt and let the bolt face seat the primer and then remove the case.

Next measure the case again checking to see how far the primer is protruding from the rear of the case and write it down.

Now subtract the first case measurement from the second and this will be your head clearance.

If your wildcat cases are on the short side, from shoulder to base your head clearance will be excessive and the cartridge may fail to fire.

Meaning you may have too much foam and not enough beer in your chamber for a good healthy shot.

Congratulations you now know how to make the cheap bastards headspace gauge (head clearance gauge) ;D

Excellent!

 

[jlow]

If you are measuring the seating depth of the primers that failed after you try to fire them, this is not a test for proud primers.

When a primer is not seated properly i.e. they protrude above the head and this needs to be detected before they are fired. If you missed them, firing them will seat the primer down properly but the force used to move them to the proper position has robbed them of enough impact force against the anvil that they will not fire. They may or may not fire when you chamber and try to fire them again.

This is the MOST frequent cause of FTF rounds. The only way you can detect this problem is to finger check enough of your loaded and unfired rounds. Run your finger across the seated primer and any proud primers will be detected easily. If you don't check your primers after you seat them and you find proud primers now, you know what the problem was.

 

[JeffG]

Thanks for ALL the responses! The cartridge is 270 Redding (based on 308 win case). Brass is all same lot, brand new Lapua 260 rem, just necked down to hold the .277 pills.

Savage 99's are hard to headspace, as the bolt seats up into a wedge at the heel. A little further up/further down the wedge shape creates different headspace, and bolt face squareness. But again, I'm very confident of the headspace work done by a meticulous 'smith.

I will try the shade-tree headspace test!... , if only for the reward after the sudz goes down!

 

[sundance]

How many rounds on the firing pin spring? Kelbys got my Stolle bolt back for some work recently and changed the spring out.They reccomend a new spring every 3000 rounds.They said mine was weak.I can't even imagine what count some of my varmint actions have on their springs.

 

[JeffG]

Damn it! I just did the pilsner test.. with unfired new brass, and fire formed brass. Variation in the brass length was .0015" longest to shortest for each. Variation from the unprimed brass to the primer-seated-by-the-bolt length is .010" for both new and fire-formed.

The new brass is seating against the middle of the shoulder ramp as they should, just checked by putting magic marker on the shoulder.

I will definitely address this with the 'smith, but will a second fire-forming move the shoulder forward that .010"?

Maybe I should be using 7-08 brass?

 

[bigedp51]

Thanks for ALL the responses! The cartridge is 270 Redding (based on 308 win case). Brass is all same lot, brand new Lapua 260 rem, just necked down to hold the .277 pills.

Savage 99's are hard to headspace, as the bolt seats up into a wedge at the heel. A little further up/further down the wedge shape creates different headspace, and bolt face squareness. But again, I'm very confident of the headspace work done by a meticulous 'smith.

I will try the shade-tree headspace test!... , if only for the reward after the sudz goes down!

You are fire forming cases, the reason I made my first posting wasn't to question your rifles headspace setting, I made my first post to make you think about your cases being too short for the chamber. Meaning excessive head clearance, if you are coming up short you need to think about creating a false shoulder or seating your bullets long and jamming to keep the rear of the case against the bolt face.

And my "shade tree" headspace test will check your gunsmiths work with you being the quality control inspector.

 

[Webster]

I had some Fed 205 primers 2 years ago. I had misfires and one hang fire. Switched to Rem 7 1/2 BR primers. Not a single problem since then. Later I bought a Tubbs replacement firing pin assembly since the spring was 40 YO. Before you get involved with gunsmith work or spending money. Try 1 or 2 other brands of primers. Borrow some or buy a single box of 100. I doubt that you contaminated the primer with sizing lube. There no reason to have lube on your fingers when priming. Even if there was you are only touching the external surface of the primer cup.

 

[JeffG]

Yeh,...I know how not to have wet case lube around primers..I was just hurrying to get to the range before dark, and I was not being careful, so that was my most likely culprit.

Primers were CCI-200, I have others to try.

I will try seating the bullets long to keep things back against the bolt face, and see how they form on the next round.

Thanks everyone!

 

[jlow]

You may have found your problem with the primers but since your headspace was so far off, you may have problems with the short ones thinning at the head and heading for case head separation. I would do the paper clip test on them.

 

[amamnn]

My take on this kind of thing is a bit different from what I have read above.


It seems to me I am hearing a lot more complaints about primers failing to fire in the last three years than previously---some 50 years---some before the www when we had to rely on the dino express riders to bring us word of such happenings..............

Anyway, I have had FTFs with all the major brands of primers the most recent being with Remington 7-1/2 primers I bought during the first Obama panic because I could not get my usual Federal 205GMs. I have not used them much and was trying to find a use for them besides FFing since I have so many. Upon inspection after disassembling the cartridges that failed to fire, I found that there was no anvil in the 3 primers that failed. This is nothing new, nor is it restricted to this brand-- if you do this long enough you will find duds in the best most stringently inspected ladeda match grade primers. People make mistakes--I think I made mistakes by not inspecting the primers more closely before using them, but this kind of thing is so rare, you get lazy--except for one brand which I WILL NOT BUY EVER EVER again after repeated failures of different lots of alleged BR primers in different rifles---and in friend's rifles after they would not believe me and I gave then the !#@$^#^$ things and then they became believers, but hey! I don't obssess about these things... a lot... anymore....hardly.

Of all the alleged match grade primers I have used the 205GM remains the most consistent and trouble free..................and according to a test that IBS shooters may remember that was published years ago in PS, it take a lot of oil to drown a primer to the point it fails to fire.........letting the cartridge roam free in the chamber---well, that's a different story.

 

[searcher]

1+ for what 22brguy said about the Wolf primers - but that also applies to the Tula primers as well. No room for weak springs or excessive shoulder space - or deep primers pockets from alteration.

 

[Webster]

I forgot to mention when I had the bad Fed 205 primers the anvils had a dark color or stain on them. The primer cakes sometimes were stained also. A few of the primer cakes were cracked.

The Rem 7 1/2 BR primer anvils are a more uniform copper color all over. The primer cakes are uniform in a clean looking color without cracks.

Don't remember which primer brand but one lot had burrs on the anvil edges like it was punched out with a dull or worn out die. Does someone out there know if the dark color on Fed 205 primers is normal. I still have them. When you get a new box of primers put a 100 in the primer flipper and look at the anvils and primer cakes of about a bunch of them. It only takes about a minute. You need about a 5X hand magnifier.

 

[JeffG]

My next round of fire-forming had no misfires, with the bullets set long to jamb the lands, and the Pilsner primer headspace check showed that my expanded cases filled the chamber nicely.

So I'm thinking my excess headspace was the most likely cause of the mis-fires.

Thanks again,
Jeff