M41 failure to fire

I just submitted a response to a member regarding consideration of buying a S&W Mod 41. Now I find myself asking for help for my M41 from those who have worked on and discovered the solution for the "failure to fire" a chambered round. It occurs after loading from a five round or ten round magazine in both slow fire and sustained fire sessions. The offending round remains stuck in the chamber. After removing the round with a wooden dowel and replacing it in the magazine, the round always fires (not a dud). Frequency is once or twice in a magazine, but always sufficient in sustained fire to require an alibi and we know what that means. There is little evidence of a firing pin strike on the rim.
I only use CCI SV ammo. In the past, I have gone as far as to wipe off the excess wax build-up on the bullet and brass on each and every round (yes I know). The gun is cleaned and sufficiently lubed. The chamber has been brushed with a nylon brush (one size up from .22). The chamber does pass the "plunk" test. I have liberally used gun scrubber on both ends of the firing pin. The firing pin moves freely at the touch. Today, I replaced the factory 7.5 lb recoil spring with a 6.5 spring from Wolf without eliminating the problem.
I would greatly appreciate 1) your thoughts and suggestions/remedy on the scenario described and 2) your opinion of the effects to the chamber/barrel of placing a drop of oil to the top of the first bullet in the magazine as a temporary remedy (suggestion from others). From what I have read, my next consideration is to have the firing pin and firing pin spring replaced. Thanks, Joe

If you do not see evidence of a firing pin strike, that tells me, the firing pin is not hitting the rim.

And then, an unfired case is stuck in the chamber.

I think the chamber is too tight. Check to see that the firing pin has not created a dimple on the rim of the chamber. If the firing pin hits the back of the barrel, it will create raised section that will cause a tight chamber.

Other than that, I think it possible the chamber is too tight due to a worn chambering reamer.

My guess is that the slide is  not going fully into battery, the hammer hits the thing and pushes the case further into the chamber. Some how the hammer is not reaching the firing pin on the first strike.

Then, given that the slide and hammer have resized the case, the next time it goes in, it seats fully.

Dear JJ:

Lots of possibilities.  

Next time your gun goes click, before you do anything see if you can push the slide forward into battery.  Lots of times the bolt is a short distance back from the breach and the hammer cannot hit the firing pin.  

First off, put a brand new s&W 7 1/2 pound spring in there.  a lot of shooters put in a lighter weight spring and it just does not have the strength to push the slide forward with the new round and get it fully into battery.  Also, a older spring looses strength as well.  its a $4.00 item so get a couple while your ordering some. 

Secondly, I would remove the bolt from the slide and remove the firing pin and clean that all out.  easy and simple to do.  While you are at it, do a complete field strip and clean of the pistol.  Make sure the slide racks easily on the frame.  

next, I would start putting a drop of oil on the first round of the magazine.  Some people object to this but model 41's like to run wet.  

Still having problems?  see if you can observe the pistol in operation or have someone shoot it while you look at its operation.  sometimes you can see that the slide is operating in "slow motion".  I have had a couple model 41's that I needed to strip down to removing, cleaning, and reinstalling the hammer.  While I could not see the grit in the hammer pin, something was sticking up the hammer and it got fixed while disassembling, cleaning, and reassembling to this point. 

If you need some detailed instructions with pictures, send me a email at crankythunder@yahoo.com.  I got some good instructions but reassembling the hammer in a model 41 requires a trained miniature octopus and you gotta hold your tongue just right to get all the springs aligned for installation of the hammer.  If you have a cocking indicator, install that and clamp it with a small pair of hemostats to hold it in place while you fiddle with the other twenty three parts.  

Regards, 
Crankster

Agree with Cranky, put a new 7.5 recoil spring in..going lighter is the wrong direction.. Also check your bolt to be sure it's not loose. Take the pin out and see if it moves side to side

I will just add that the drop of oil on the first round is to oil the bottom of the bolt that rides over the hammer as the slide cycles. My CCG 41's have the bottom of the bolt polished and I place 4 -5 spots of gun grease on the shiny portion that forms a T shape. This reduces the drag on the slide as it is cocking the hammer. I have zero issues like you describe with the possibility that a power puff round does not cock the pistol. Factory recoil spring and I change it after every two cases of ammo. 

Best of luck with this issue.

22s are notoriously gritty, if you have a buildup in the chamber, it won't fire.

Clean with Kroil ( wear gloves) and a brush.

Or brush it.

Should help

My thanks to those who have responded. I read all of your thoughts and suggestions. Not sure that I understand all that was said and I will re-read for better understanding.
I have replaced the Wolf spring with a new factory S&W 7.5 spring. I have again cleaned the chamber with an oversized nylon brush, re-cleaned the bolt face (only slightly dirty) and used a menck tool on the chamber. I lubed the bottom of the bolt, especially where it forms the top of the T shape. After lubing, the slide moves easily on the frame. Then, I went to the range this afternoon.
Observations: I continued to have failure to fire on 7 out of 60 rounds fired (all slow fire) with no firing pin strike marks on the 7 rim. Before removing the round from the chamber, I checked to see if the slide was completely in battery - it was every time. After removing the stuck round from the chamber, I examined it, placed in back in the magazine, released the slide and the rounds always fired. 
On my next trip to the range, I will ask someone to observe and compare movement of the slide when I have a failure to fire. I have not run a bore brush through the barrel unless accuracy falls off. I have little gunsmithing skills and no tools. I have watched Utube on replacing firing pin, spring and extractor. Have not performed any maintenance/cleaning on the hammer, springs or pivots. Further suggestions or ideas on why I have occasional failure to fire and suggested remedies would be greatly appreciated. Thanks, Joe

Be sure and mark your magazines and see if the light strikes are isolated to one mag.. also only load one round at a time into the magazine up to the five rounds. Pull the follower down just enough for the round to be loaded then proceed to the next round. This insurers the rims stack correctly in the mag.

jjbhonn wrote:My thanks to those who have responded. I read all of your thoughts and suggestions. Not sure that I understand all that was said and I will re-read for better understanding.
I have replaced the Wolf spring with a new factory S&W 7.5 spring. I have again cleaned the chamber with an oversized nylon brush, re-cleaned the bolt face (only slightly dirty) and used a menck tool on the chamber. I lubed the bottom of the bolt, especially where it forms the top of the T shape. After lubing, the slide moves easily on the frame. Then, I went to the range this afternoon.
Observations: I continued to have failure to fire on 7 out of 60 rounds fired (all slow fire) with no firing pin strike marks on the 7 rim. Before removing the round from the chamber, I checked to see if the slide was completely in battery - it was every time. After removing the stuck round from the chamber, I examined it, placed in back in the magazine, released the slide and the rounds always fired. 
On my next trip to the range, I will ask someone to observe and compare movement of the slide when I have a failure to fire. I have not run a bore brush through the barrel unless accuracy falls off. I have little gunsmithing skills and no tools. I have watched Utube on replacing firing pin, spring and extractor. Have not performed any maintenance/cleaning on the hammer, springs or pivots. Further suggestions or ideas on why I have occasional failure to fire and suggested remedies would be greatly appreciated. Thanks, Joe

I am going to throw a Hail Mary:  Remove the firing pin.

Go to this link :    S&W Model 41 detailed dis-assembly and assembly instructions 

Read the discussion and go to the referenced page.

I think there is the chance that something is broken within the firing pin channel. Maybe a spring coil is jammed in there, maybe the bird of paradise flew in. I don't know. But if something is broken, and lodges occasionally, then movement of the firing pin would happen. I would think it would be all the time, but you know, it could be some of the time. It won't hurt to clean the inside of the block and channel out of all the oil and congealed goo that is in there.

See if you can buy a replacement firing pin and firing pin spring. These are always worth having anyway, examine the replacements against the originals. See if there is anything obvious. Then install the replacements and shoot the gun.

Short of a full disassembly and cleaning of the lower (frame), clean it well with a spray cleaner, and carefully inspect in bright light.  I had intermittent problems firing with my SW41.  It turned out to be a bit of translucent brush bristle (hard to see) that was stuck and occasionally blocked firing.  Make sure nothing is hindering the sear, hammer and other attached mechanics.

A broken firing pin can behave like this. In two pieces, they have noplace to go and the gun can fire when they bash into each other, most of the time. Agreed it's time to pull the pin out and check everything in the channel.

I was thinking a carbon ring in you chamber.  That could hold a round slightly off the breech.  When your firing pin hits the round it would just push the round forward.  Then if the ring was built up enough the round could get stuck.
You would need more than a nylon brush to remove it.

Take the barrel off the pistol and hold it vertically with the chamber up.  Drop a round in the chamber and see if it makes a plop sound and bottoms out in the chamber.  Then turn the barrel upside down and does the round drop out?  If not, then your chamber is not clean.  Use a bronze brush that is oversize to clean it with a good cleaner.  I shoot centerfire and use an old 0.243 brush that works well.

The other suggestions are good as well, but if you cannot pass the plop test then start with getting the chamber clean.

I am truly grateful to the many who have read my issues as well as to those who have offered suggestions. After Friday's ideas, I did an even more through cleaning of the chamber and bolt face. I again used my nylon chamber brush .243 (one with a 90 degree bend and a straight one on a brass cleaning rod). I also ran a regular bronze cleaning brush with an additional strand of chore boy one way through the barrel, following that up with patches. I performed the "plunk" test again and was successful both in the drop and falling out. I again used the menck tool on the chamber (to ensure that the firing pin is not causing damage to the chamber, during this time of resolving my issue, I have ceased dry-firing with this M41 even with a dry wall anchor). As suggested, I replaced the new 6.5 pound Wolf recoil spring with a new S&W 7.5 pound factory spring. I re-lubed and put it away.
Then yesterday afternoon, I went to the range. Ammo used has always been CCI SV. For all of my testing, I used my SF magazine (best one after RR testing) and loaded 10 rounds for shooting SF at 50. Thirty rounds were shot without a hitch. Moved to 25 yards for more SF for me and my wife shooting two handed. We both had problems - about 5 rounds out of 30 rounds loaded. Each offending round remained in the chamber. Each time, I verified that the slide was completely in battery. Inspecting each round after removal, there was no evidence of the firing pin having made contact with the rim. Upon replacing the offending rounds in the magazine at the same place, each went bang. Unless I hear of a new or different suggestion, my next plan is to remove, clean and replace the firing pin, firing pin spring and extractor. I have extra S&W firing pin and spring from Brownell's. 
My observations tell me that the firing pin does not always strike the rim, but when it does, it goes bang. I can deal with that is SF but not continuous fire. I will push back from the table, take a little time away from my situation to get my head on straight. I will get back to the committee. Thanks and regards, Joe

Didn't see this above.  Change the trigger overtravel screw at least 1/2 turn (inward on a M41) for more clearance to make sure the trigger is pulling the sear completely away from the hammer.  That will make sure the sear isn't rubbing the hammer on the way down.  Sometimes they are set so close it's a issue due to the hammer / sear design on the M41 and can show up with a little wear or too close overtravel setting.

Use a brass .243 brush for the chamber.  If it is a carbon / wax ring buildup that nylon one probably isn't getting it all.

No need for brass in the bore unless you see lead after doing a pull through patch.



CR

Purchase a pardini.

r.tornello wrote:Purchase a pardini.

Sigh!

Why is it the answer is always buy a Pardini, no matter what the question is?

Because it's the right answer! Those of us who have had them know.

NO-thing is perfect, but these come close.

I've had Hammerlies, FWB 93, M41s, and more that I can't even recall with out going to my record books. Pardini stands out unless I was a member of the old  Soviet (not Russian team), then I might have a problem.

Just call Pardini in FL before FL sinks under the ocean rise and purchase the gun. Get some extra magazines, some spare parts, find some old Don Nygord comments and training documents, learn how to properly maintain the gun and go shoot.

Oh yeah, find a grip that actually fits. That's the start of a good shooting program. Pilkington might be able to help there with some of their IGOR whatever his name is comments and suggestions.

I had the same thing happening in my Pardini with
CCI SV. I determined it was the excessive wax on the bullets that was interfering as the round was chambered.
Changed ammo to Agila and never saw this issue again.
CCI used to run great in this pistol but after three cases the fourth was not working out.
This issue will only get worse as the temp goes down here on MA.
G