.223 Misfire Mystery (?)

[Turkeytider]

My Savage 110 .223 has around 500 rounds total through it. Until today, zero misfires. The first three rounds ( Frontier 55grain OTM ) today were all misfires. Primers were indented, leading me to think light strikes. From that point on, 20 rounds ( including the three misfires ) all fired normally.

One thing I did differently was, instead of my usual snap cap, was to de-cock the gun by opening the bolt, holding the trigger back, and closing the bolt. I`ve read that this is a way to de-cock a gun, but is it possible that it had some sort of effect on the firing pin operation? Welcome any thoughts from all of you. Thanks.

 

[Dave DeLaurant]

Did you try a restrike on the FTF rounds? If they failed twice, I'd pull the bullets and powder and see whether a hammer and nail will set off the primer.

Factory ammo problems are rare, but not unheard of. I think the most common (which is to say really, really rare!) is a missing anvil in the Boxer primer. Three in a row should qualify you for a lucky win on the lottery.

Light strikes are the mostly likely cause. The 110 bolt isn't the easiest to disassemble, but I think it's worth checking for debris inside:



Lowering the firing pin via the decock method won't harm the firing pin -- if anything, it should help preserve it.

 

[Turkeytider]

Did you try a restrike on the FTF rounds? If they failed twice, I'd pull the bullets and powder and see whether a hammer and nail will set off the primer.

Factory ammo problems are rare, but not unheard of. I think the most common (which is to say really, really rare!) is a missing anvil in the Boxer primer. Three in a row should qualify you for a lucky win on the lottery.

Light strikes are the mostly likely cause. The 110 bolt isn't the easiest to disassemble, but I think it's worth checking for debris inside:



Lowering the firing pin via the decock method won't harm the firing pin -- if anything, it should help preserve it.

Yes, all 3 misfires fired normally the second try.

 

[Howland937]

Any recent maintenance or cleaning? Overly lubed or gunk impeding the firing pin travel until it cleared out? Especially if everything including the misfired rounds worked afterwards.

 

[badkarmamib]

see whether a hammer and nail will set off the primer.

Do NOT do this. I have a permanent scar on my left pinky from the primer flash peeling the skin open.

 

[Turkeytider]

Any recent maintenance or cleaning? Overly lubed or gunk impeding the firing pin travel until it cleared out? Especially if everything including the misfired rounds worked afterwards.

That`s kind of along my lines of thinking. No maintenance or cleaning beyond the usual. Maybe some micro-junk or something that cleared out. I took a small probe to the firing pin channel and LIGHTLY lubed it, then did several snap cap dry fires. With a bad firing pin spring or such I would have expected additional light strikes.

 

[David Hoback]

Very possible it had some grit caught up in the FP. Or the Action was just being a bugger. Or, most likely…,that since Frontier is loaded by Lake City, meant for Ar’s & uses harder primers, those 3 rounds were just right on the threshold.

I wouldn’t worry about it. If you start seeing it with other ammunition, then it’s time to dig a little deeper.

 

[Ru4real]

…is it possible that it had some sort of effect on the firing pin operation? Welcome any thoughts from all of you. Thanks.

Probably not. Make a measurement as to how far the firing pin protrudes past the bolt face. I have a Savage that I need to change from 0.025” factory setting to 0.045”. The consensus from thread below was no known standard and often 0.035” is cited as the minimum.

How far should a firing pin protrude past the bolt face on a center fire bolt face?

Recently I had light strikes and misfires with a new Savage Axis II, a common problem I’ve read. The firing pin protrusion was 0.025” from the factory. So I milled the firing pin rod stop face down 0.020”. Now the protrusion is 0.045” as measured off the bolt face. No more ignition issues.

Yesterday I had a couple fail to ignite with my T/C Venture II. Turns out just bad factory rounds. Today I measured the firing pin protrusion and it is 0.060” as measured off the bolt face. Appears to be plenty.

Today I also measured a Winchester M70, and it’s firing pin protrusion is 0.045” as measured off the bolt face.

Three different guns, three different factory numbers. Is there an accepted thumb rule or number?

If protrusion is good, consider replacing (or stretching) the spring which is a known trouble spot with some Savages.

Or do nothing and assume it’s the ammo.

 

[Turkeytider]

Very possible it had some grit caught up in the FP. Or the Action was just being a bugger. Or, most likely…,that since Frontier is loaded by Lake City, meant for Ar’s & uses harder primers, those 3 rounds were just right on the threshold.

David, thanks. I`m curious about your statement concerning harder primers being used at Lake City. Is this something that`s well known? Why would this be? Since all rounds ended up firing without further FTFs, I`m not going to worry about it unless/until I get additional FTFs with different ammunition.

 

[GerryER]

I had a similar problem with some PMC FMJBT 55 gn .223 ammo. Three rounds in a row failed in my BLR, so I put them in my AR and 1 fired and 2 did not. Same thing happened with another box of 20 of the same ammo. Definitely bad primers, and this doesn't give me a lot of confidence with the PMC ammo. Also, you might consider that in some instances, the primers are not fully seated, and the first strike seats the primer and a re-strike sets it off; usually happens with poorly done reloads, but can happen with factory loads.

 

[Turkeytider]

I had a similar problem with some PMC FMJBT 55 gn .223 ammo. Three rounds in a row failed in my BLR, so I put them in my AR and 1 fired and 2 did not. Same thing happened with another box of 20 of the same ammo. Definitely bad primers, and this doesn't give me a lot of confidence with the PMC ammo. Also, you might consider that in some instances, the primers are not fully seated, and the first strike seats the primer and a re-strike sets it off; usually happens with poorly done reloads, but can happen with factory loads.

Interesting. I`ve used a fair amount of the same PMC loads as range fodder. and never had a failure with them. For a FMJ round, with their inherent less than stellar consistency when it comes to precision, my gun has shot them pretty well, Can get a 1 MOA group, but certainly not as consistently as with other rounds.

 

[FL-NC]

I've seen this happen in 700's that had a titanium "reduced lock time" firing pin.

 

[243winxb]

One thing I did differently was

Stop. See if it fixes misfires?

 

[David Hoback]

Military primers have always been harder. Yes, this is something known.

 

[Turkeytider]

Stop. See if it fixes misfires?

Yep, I did. Went back to using snap caps, although I don`t necessarily think that changing how I de-cock the gun was the cause of those misfires. I think it`s more likely something interfering with the firing pin function ( trash, gunk ) that worked itself out after the misfires, or hard primers. Haven`t had a chance to check at the range.

 

[Dave DeLaurant]

Do NOT do this. I have a permanent scar on my left pinky from the primer flash peeling the skin open.

Would you please share some specific details on your accident -- cautionary tales are always helpful.


For my own part, I neglected details on how to do this safely. I use basically the same nail technique to tests for corrosive priming. This clever guy uses an SKS bolt, but a dull nail will do the job. Just a tap with a light hammer.



Gloves + face shield + hearing protection are required!



I've never suffered an injury from a primer, but I did give myself one heck of a scar one time when I was trying to muscle a stuck .308 case from a Lee hand press. The case suddenly separated, and I was exerting so much force that I lost control of the hand press and pinched the jagged edge of the separated case into the web of my left hand between the thumb and forefinger.

 

[badkarmamib]

Would you please share some specific details on your accident -- cautionary tales are always helpful.

In one of my rare (see:frequent) moments of stupidity, I had crushed a case during the seating process, beyond recognition, and didn't want to send a live primer to the scrapyard. I had hammered twisted primers on the concrete floor before, no big deal. So, I put the case head-up in a vise, pin punch in the left hand, hammer in the right. Whack, primer went up the punch, flash went around, and blood poured. Half the finger pad was dangling, and it was "painfully" obvious how bad of an idea it was.

 

[Dave DeLaurant]

In one of my rare (see:frequent) moments of stupidity, I had crushed a case during the seating process, beyond recognition, and didn't want to send a live primer to the scrapyard. I had hammered twisted primers on the concrete floor before, no big deal. So, I put the case head-up in a vise, pin punch in the left hand, hammer in the right. Whack, primer went up the punch, flash went around, and blood poured. Half the finger pad was dangling, and it was "painfully" obvious how bad of an idea it was.

I can soundly beat that for stupidity -- in my mid-teens I had an UD with a flare pistol in my bedroom. Parents were on vacation and dad never did ask me about that scorched area of linoleum.

 

[AK Hunter]

You may have some junk around the firing pin. Disassemble the bolt & clean/lube the bolt should take care of the problem.

 

[Turkeytider]

Status update: Fired a number of two different brands of ammo. Did not shoot any Frontier this time. Zero misfires. Still don`t know for sure what caused the original misfires, but confident that there`s no inherent problem with the bolt and firing pin mechanisms. which is the main thing. Thanks to everyone who contributed to the thread.

 

[David Hoback]

I do… it was THAT specific ammo which caused it, LOL! I recommend staying away from it.

I’m just having a go. I know you get it.

 

[Turkeytider]

I do… it was THAT specific ammo which caused it, LOL! I recommend staying away from it.

I’m just having a go. I know you get it.

Yep! I have a little more Frontier ammo, particularly some 68 grain OTM I want to try. Maybe there`s actually something to that about harder primers coming out of Lake City, though.

 

[David Hoback]

Oh, there’s no question about that. It is FACT! Any NATO ammo is going to use harder primers because the M16/AR15 & also the AR10 use a “Floating” firing pin. Upon bolt closing, the FP can freely contact the primer under its own weight. A harder primer was simply an extra measure against slam fire.

It’s one of those little AR15 “tid-bits” one knows from a life of research of the platform.