Miss-fires with .22 LR ammo - SOLVED!

[SSL]

I had a neighbor drop off a Stevens Model 15-A for me to work on. He was complaining that it had been miss-firing with frequency of late and getting worse. It had been a while since he had shot it and heard I worked on guns occasionally. It isn't a rifle of value, being a single shot that requires the striker to be pulled back before firing and probably cost $3 -$5 new, and mostly sits in his barn for the occasional rat, raccoon or opossum. It was evident that it had problems when he handed it to me and the entire striker assembly fell out of the bolt. The long, threaded pin that holds the striker assembly in the bolt and the firing pin spring under tension was missing! When asked, he said that it had been missing for a while. How it ever shot to begin with is a mystery.

Now, let me stress that I'm not a gunsmith, but I do most of my own work on my own guns. I do not charge for work on other peoples' guns (only for any parts that might be needed) and only tackle what I'm pretty sure I can fix. Instead of charging, I make it part of the deal that they do something for someone else.

A replacement pin was found and the bolt reassembled, the bore action and striker assembly thoroughly cleaned, a burr removed from the crown, action and barrel polished and re-blued and the stock refinished (just for fun). In the process of test-firing, I had perhaps 2 out of 20 rounds fail to fire. This average continued through 60 rounds before I called it enough. In each case, I found that the rounds that failed to fire had good, deep pin dents and trying them again with the cases rotated to present a different portion of the rim to the firing pin resulted in only one round firing on the second try. These rounds were all Remington and Winchester WalMart "box" bullets (the ones he uses and he dropped off a couple boxes for testing purposes). It didn't dawn on me to try them in one of my .22s until after I had discarded them.

My question, after the long introduction, is does anyone else have this problem? Is there something I'm missing on his rifle that needs fixing or is today's mass-produced inexpensive ammo that inconsistent? I plan to try some CCI ammo later, but thought I'd toss this out for ideas.

 

[1911nut]

I’d brush the chamber with a nylon brush and solvent and try different ammo.

 

[jpx2rk]

I've had a few Eley Match (black box) and CX FTF after 2 or 3 or attempts. I don't consider it abnormal, I am a bit surprised by the round not firing after 2 or 3 hits, but a dud is a dud.

 

[mills braswell]

Sometimes you can get bad batches of 22 rimfire. The next time you have a 22 rimfire that misfires, but is left with a good indention on the rim from the firing pin, pull that bullet and dump the powder. Many times you will see that their is no flash compound in the rim at the corresponding spot where the pin struck the rim. That is why a lot of times you may rechamber the round and it fires. The pin hit the rim where flash compound exists. It may not be your problem but definitely something to think about IMO.

 

[SSL]

I've had a few Eley Match (black box) and CX FTF after 2 or 3 or attempts. I don't consider it abnormal, I am a bit surprised by the round not firing after 2 or 3 hits, but a dud is a dud.

I am too. The pin-strike is far more than enough to have fired the cartridges and the dents are heavy. I've seen light strikes before with other guns and usually means a peened pin or a dented chamber mouth from dry-firing. This has me puzzled. I'll be trying different ammo when Mama's doctor appointments let up and I have the chance.

 

[jpx2rk]

If the ammo the gun owner dropped off is very old, that may contribute to the FTF issue as well. Or stored in the barn along with the gun ?????

 

[PigButtons]

Both brands of the ammo you mentioned have poor reputations lately. That said, many older rimfire arms can benefit from a little reshaping of the firing pin. Please post pics of the firing pin strikes on the cases. Usually the pin is either too wide or is hitting too far in from the outer edge of the case. When either of those happens too much energy is absorbed in deforming the case, slowing the firing pin enough that the primer compound doesn't ignite.
Optimal strikes are 1/32 to 1/16 inch wide, and run from the outer edge in about 1/16".

 

[SSL]

Both brands of the ammo you mentioned have poor reputations lately. That said, many older rimfire arms can benefit from a little reshaping of the firing pin. Please post pics of the firing pin strikes on the cases. Usually the pin is either too wide or is hitting too far in from the outer edge of the case. When either of those happens too much energy is absorbed in deforming the case, slowing the firing pin enough that the primer compound doesn't ignite.
Optimal strikes are 1/32 to 1/16 inch wide, and run from the outer edge in about 1/16".

I luckily found a few of the cartridges in question. The top row is fired cartridges from the rifle with no issues. The second row shows two that refused to fire even with repeated tries, a Federal and a Super-X. The pin imprints on the fired cases look similar to the width and depth of my Browning T-Bolt, which has never failed to fire. Actually better than I normally see in rimfire rifles made in the '30s through '60s with years of hard use. Hard to focus perfectly at such a close range, but notice that the indents appear deep enough and uniform. I pulled the bullets from the two that failed to fire and they did contain powder and enough priming compound to at least flare slightly when heat was applied.
Though the powder looked dry, perhaps moisture killed the priming, as @jpx2rk suggested. I'll try ammo that I know to be good when I get a chance.

 

[NZ_Fclass]

It is often the ammo not fully sitting in the chamber, with the result that the striker energy is absorbed by the movement of the cartridge. Can be a build up of lube/wax, dags on the chamber or even something impeding the striker and slowing it. Best of luck.

 

[SSL]

It is often the ammo not fully sitting in the chamber, with the result that the striker energy is absorbed by the movement of the cartridge. Can be a build up of lube/wax, dags on the chamber or even something impeding the striker and slowing it. Best of luck.

Just to cover your remarks, all very good ones, the minimal design of the rifle requires one to physically insert each cartridge with a finger. Inserted cartridges feel like they seat solidly, but no guarantee. I inspected the seating area of the rims to check for dents and/or gouges from dry-firing over the years. Surprisingly, there were none. The chamber and bore were both subjected to very deep cleaning and borescoping at the time I started work on the rifle. The striker/bolt assembly was taken apart and what appeared to be generations of oil/grease sludge thoroughly cleaned off, inspected for wear, burrs or rub marks, blasted with more cleaner, wiped with a cloth with a couple drops of Hobo Oil on it and then dried before reassembly. There was very slight peening of the end of the firing pin that I lightly squared without changing the length (as you can see by the pictures, the indents all look clean, consistent and deep).

For right now, I'm leaning towards the idea that the ammo was contaminated in some manner. I'll be checking that when I can. Thanks for your ideas and time taken. If I get it figured out I'll let everyone know!

 

[PatMiles]

Given the age of the rifle how about disassembling the bolt, give everything a good cleaning and consider a new firing pin spring? Is the breach face dinged from dry firing? If so, the firing pin could be peened from the strikes and shortened.

 

[Rook 6]

Looks like most of the bases have been covered here. I’d try different ammo like you mentioned. Another remote possibility might be excessive head space but seems unlikely.

 

[stork]

First thing I check is an accumulation of crud in the bolt recess. It forces the round away from the bolt face enough to prevent the firing pin from delivering a hard enough strike to the priming mixture. This can be easily removed with a toothpick. The next thing I check is that the chamber is brushed out and clean.

From an ammo standpoint:
As an avid Bullseye shooter, I go through 5-10,000 rd's of 22 LR every year for the last 23 years. I've experimented with just about every brand looking for an ammo that was both accurate and reliable. Pistols used are a variety of Ruger MKII's, Hi Standards, Walther GSP, Marvel and Nelson conversions. I've found both Remingtom & Winchester to have a VERY high percentage of duds. Sometimes you can get an entire brick to function flawlessly, and the next brick won't run 5 rounds without the dreaded "click".

I had 5 cases of Remington standard velocity ($95/case, delivered.. Different times.) that was superbly accurate, but was so unreliable it was only used for "ball & dummy" practice or slow fire.

Eley, Lapua, RWS have been excellent. For less expensive & reliable ammo CCI sv is quite dependable. Best recollection is less than 10 duds in roughly 15 cases (75,000 rds).

These are not good times to have to get a particular brand, so quite often we have to settle for whats available. Just remember to stock up in good times!

 

[SSL]

Given the age of the rifle how about disassembling the bolt, give everything a good cleaning and consider a new firing pin spring? Is the breach face dinged from dry firing? If so, the firing pin could be peened from the strikes and shortened.

That has all been done (see post #10). The spring delivers a rather enthusiastic dent to the cartridges...whether they fire or not...so I doubt if that is the problem. Again, I'll try it with know quality ammo next.

 

[dellet]

CHeck the rounds that don’t fire to see if the bullets are engraving into the lands. Pay attention if the engraving or marking is symmetrical.

Looking at the rounds pictured, the firing pin marks don’t seem to clip the edge of the rim every time. It’s possible a mis-shaped bullet is keeping the round from seating in the chamber. Combine that with a weak,slow firing pin and there may not be a sharp enough strike. Just pushing the round back and forth in the chamber.

 

[Ggmac]

Are there any impressions on the foward part of the rim , indicating a chamber that has had many dry firings and when the striker ( fp ) hits it merely moves the brass. Without a solid backing itll look like a good hit , which it is , but not enough metal on the chamber to detonate the primer

 

[SSL]

Are there any impressions on the foward part of the rim , indicating a chamber that has had many dry firings and when the striker ( fp ) hits it merely moves the brass. Without a solid backing itll look like a good hit , which it is , but not enough metal on the chamber to detonate the primer

No. Checked that when I had it apart. Actually was surprised.

 

[jsn]

Looking at the pic of cartridge heads you posted, some strikes are into the edge of the rim, some aren't. Did you fire the FTF Federal and SuperX in different guns? The strikes that went into the rim edge on these do not look the same as those on the fired cases to me, but it might just be the photo.

Looking at the face of the bolt, is the firing pin hole elongated or otherwise not the same shape as the part of the firing pin that passes through it?

I've had some FTF issues with Walmart bulk box ammo that the same brand in 10x50 bricks didn't have. In several brands (T-Bolt comes to mind right now).

It appears you looked at the priming compound on two rounds, sometimes on rounds that refuse to fire after several strikes the priming compound is not consistently around the inside of the rim, thin/thick, sections missing, I've even seen a spirals from halfway down the inside of the casing that ends before the rim (Aguila).

 

[PigButtons]

Thanks for posting the pics. They're very informative. But I'm thinking at this point that it has to be the ammo itself. there is certainly some inconsistency where the firing pin is actually falling in relationship to the outer rim of the case. But since the same problem seems to appear on both the fired and the duds I don't think it's actually the firing pin that's the problem it's more likely the ammo.

Good work so far. I would like to hear what you find.

 

[jk80]

I really believe it's the ammo. I've been shooting a lot of long range 22 in a 513 matchmaster as training for f class and have had a lot of problems with all 22 ammo lately. Some of the older power point winchester stuff made in Australia and older eley has not been a problem. I think the manufacturers are trying to run as fast as possible and more worried about getting it out the door. None has been brand specific in my case, just as many as 5-10 misfires out of a box. Had a gunsmith look at things with the rifle and all was good in his perspective. Also happening in a 10 22 and a cz trainer. Think it's just a sign of the times.