Model 41 not firing

At the range my new to me Model 41 ( older 5 digit) would FTF.  I put first round into chamber and nothing in fact chamber indicator was not sticking out.  I ejected the round and the 41 fired flawlessly through the whole mag.  Next mag would fire a couple of rounds and same thing no ignition,  I would eject and rest of mag would work.  The only things I have done are new wolf recoil spring 6.5 and new firing pin spring kit.
Ammo is cci sv, some older federal target and eley all with the same results. Also has a Clark barrel which was fitted by Clark.  Any help woud be be greatly appreciated.  As a last resort: Any recommendations as a Gunsmith I might send it to.  
Thanks in advance
Jim

Is the slide "short cycling"? 

Changing the new recoil spring my not allow the slide to fully retract to fully cock the hammer. 

Take the slide off and see if the hammer cocks every time when you manually cock the hammer.  The protruding pin indicates the gun is "cocked"! "Cocking indicator pin!" Also check for excessive sear wear. 

Be sure to protect the frame when releasing the hammer. Remember the magazine must be in place!

Put the original recoil spring back in and see if the problem follows. 

You may have to manually hand cycle the slide a few hundred times to get the new spring "settled in"! 

I'm not a gun smith and don't pretend to be one nor have I spent the night in a fancy hotel! 

Smiles,

I had this happen with an older Model 41.  The sear was not resetting. Sent it back to S&W and they fixed it.  If your pistol is newer than 1989, it is covered under warranty. You can call them before you send it in to see when it was manufactured.  1-800-331-0852

Would the problem be caused by trigger over travel screw being out too far??
Jim

jim lock wrote:Would the problem be caused by trigger over travel screw being out too far??
Jim

Yes.

This happened to several of my 22 guns last year - for all but one, cleaning the chamber fixed it.  With the Nelson, the "fix" didn't last very long, because the chamber was too tight.

I don't recall the size brush you need to use to clean the chamber - it's a size up from the brush that comes in cleaning kits.

You might also want to look at the "dent" in the cases that don't fire, and see if the imprint is as deep as it should be.  If it isn't, cleaning the chamber may help - some of your energy from the hammer hitting the firing pin might be wasted on seating the round fully in the chamber, and the energy left over may not be enough to fire the round properly.

Reread the OP and my previous post. The gun isn't being cocked every time. The hammer locks on the sear and the "cocking indicator pin" protrudes when cocked! 

If the gun isn't cocked the trigger will not reset so the overtravel screw isn't a factor!

The hammer isn't going forward to hit the firing pin so there won't be a firing pin strike!

Smiles,

jim lock wrote:.......The only things I have done are new wolf recoil spring 6.5 and new firing pin spring kit......

It won't fix this problem, but did you put the recoil spring in the way the instructions used to say, or with the "closed end" facing forward?  
If the instructions are the same as before, open end forward, you have a good chance of wrecking your gun, because the open end of the spring can start to work its way out through a small hole, and jam the gun.

Recoil sping too hard, or mainspring too stiff in combination with recoil spring = hammer not cocked, pull trigger and nothing happens. Slide did not travel far enough to cock the hammer fully, even if spent round ejected. 

Recoil spring too soft = chamber does not close all the way as return inertia is lost, but hammer is cocked. Pull trigger and firing pin hits the round, but (round not seated all the way in the chamber) momentum moves round small space fully seating it into the chamber and losing momentum of the strike = no ignition. <<< this is probably the hardest to detect. We spent 30 minutes at the range mucking around before realizing 1mm not fully closed was causing no ignition. 

I cannot see how overtravel would hinder re-engagement of the sear. It only plays a role in disengagement if too far, your gun will not fire because not enough rearward travel on the trigger bar. If it fires you are good to go even with minute overtravel. 

Usually pre-travel hinders re-engagement of the sear if set to close to the let-off point. Components cannot re-engage because there is not enough space for them to do so.  I don't believe M41 is adjustable for pre travel but I may be wrong.

jim lock wrote:... As a last resort: Any recommendations as a Gunsmith I might send it to.  

I can recommend KC Crawford for M41 work. He sorted out my M41 very well and and had some good suggestions for work to be done.

Since Clark has done some work on the gun before, you may consider having Clark look at it again.

This gun isn't cocking every time per the OP! 

Proper diagnosis requires checking the recoil spring and sear/hammer engagement!

Smiles,

(See previous posts......)

How light can I go with recoil spring without worrying about doing damage the gun itself? Seems all firing pin springs are called heavy duty.
Thanks 
Jim

You mentioned in the OP that you put in a new 6.5 # recoil spring. Often times new springs a much higher than advertised until "broken in"!

You're asking about frame battering. The main spring slows down the slide to prevent frame battering. The recoil spring ensures reliable return to battery. I have Hi-standards with barrel peening from tons of shooting from the slide impacting the barrel shooting nothing but SV!

My M41 (bought new in 1962) with way more cycles, functions perfectly with CCI-SV ammo and has a recoil spring with many thousands of cycles with no signs of any frame or barrel peening. 

Based on your description I'd be looking at the recoil spring as being too heavy! 
When it does function and cocks properly describe how the empties are ejecting!

Retest the functioning with the original recoil spring and describe how the empties are ejecting.

I hope you are using S/V ammo!

Smiles,