Glenfield 20 misfires

[Longhunter1757]

Not sure if I should put this here or in Gunsmithing so mods if it needs to be moved please do.

OK guys, I'm at my wits end here.
A friend gave my son a Model 20 in excellent condition except it misfires constantly. I just replaced the main spring and firing pin spring and no change.
All the cases show light firing pin hits even after the spring change. I completely stripped the bolt and cleaned everything although there was little crud in it. The guy I got this from said it wasn't his but a relative's and he had the same problems so it was shot very little. I don't know if this problem was from day one or not. He did say that he got it to fire better by placing a drop of JB Weld on the front of the striker. The striker doesn't look worn in the least bit and I'm not sure it's possible for this part to wear much if at all.

Any thought or advice will be greatly appreciated!

I should also add that this problem isn't limited to one brand of ammo. Tried Federal, Remington and Winchester.

Thanks!

Rich Baker

[oneokie]

Sounds like the nose of the firing pin is not protruding enough to make a solid hit on the rim. Check fp protrusion and compare to the fp protrusion of another rimfire. Also examine the breech face for an indentation where the fp would strike if dry fired.

[Longhunter1757]

Oneokie,
I checked the pin protrusion against the other one I have (older model) and it's pretty close to the same. The breech face is as clean as can be. No marks from dry firing at all.

Rich

[Wally]

Take a fired .22 RF shell and position it so the firing pin will strike on an area not already struck---pull the trigger and see if the indent is as kit should be...Could be that the bolt face just needs to be brsuhed off & cleaned--I used a wire brush...

[Longhunter1757]

Wally,
The bolt face is clean. Pulled the extractor, scrubbed with a wire brush and used a dentist pick to make sure the edges where the cartridge rim seats was clean.

Rich

[Wally]

Wally,
The bolt face is clean. Pulled the extractor, scrubbed with a wire brush and used a dentist pick to make sure the edges where the cartridge rim seats was clean.

Rich

Ok--on an already fired .22 RF case--what kind of a dent does the FP make on the case rim...?

[Wally]

Oneokie,
I checked the pin protrusion against the other one I have (older model) and it's pretty close to the same. The breech face is as clean as can be. No marks from dry firing at all.

Rich

IOW the FP isn't indenting the case when you pull the trigger--more than likely a new Firing Pin is all you need to fix this...but it could also be the Firing Pin spring. My best guess is the FP...

[oneokie]

Did you check the firing pin for burrs? Is the inside of the bolt body clean? Is the sear clearing the firing pin when you pull the trigger? ie-the firing pin is not dragging across the sear when released?

[Wally]

I looked this up on GUNPARTS... IMHO you will have to take it apart to access the FP and see what you can determine is teh problem. Marlin uses a front & rear FP in this (any many other) models. It also has a small FP spring. To replace these parts the cost is $17.05 + Shipping. I have a problem with a 1894C this spring---same deal...had to replace both front & rear FPs and it works fine now. The Model 20 is an old model IMHO it might be wise to replace all three parts..

Front FP #402950G $7.10
Rear FP 402980C 6.60
Spring 402960C 3.35

[Longhunter1757]

IOW the FP isn't indenting the case when you pull the trigger--more than likely a new Firing Pin is all you need to fix this...but it could also be the Firing Pin spring. My best guess is the FP...

It's denting it but barely. I'll check the dent in a fired case when I get home.
I've had that bolt apart about 6 times already trying to see if I missed something.

Did you check the firing pin for burrs? Is the inside of the bolt body clean? Is the sear clearing the firing pin when you pull the trigger? ie-the firing pin is not dragging across the sear when released?

I checked all the parts for obvious burrs and found nothing. Cleaned the daylights out of it. Didn't check to see if it's dragging on the sear. How would I do that?
The one thing that caught my ear was when you pull the trigger it doesn't have a nice snappy "click" like my other one does. Sounds sorta mushy so maybe something is dragging.

[Wally]

It's denting it but barely. I'll check the dent in a fired case when I get home.
I've had that bolt apart about 6 times already trying to see if I missed something.



I checked all the parts for obvious burrs and found nothing. Cleaned the daylights out of it. Didn't check to see if it's dragging on the sear. How would I do that?
The one thing that caught my ear was when you pull the trigger it doesn't have a nice snappy "click" like my other one does. Sounds sorta mushy so maybe something is dragging.

You probably will have to remove the small pins that hold the front & rear FPO's in--then exam the FPs...I would guess one of them is the cuprit. Had this happen in my 1894C. I have three other Marlin .22 RF rifles and IMHO replacing the FP's should solve your probelm. Good thing one can still get parts for it....it was no longer made after 1966!

[Longhunter1757]

Well, like I said, I had that bolt apart half a dozen times already so I think I can probably do it with my eyes closed now.
Every part in there looks almost new but obviously something is out or whack.
Guess I'll just bite the bullet and get the 2 firing pins and the striker and just be done with it.

Thanks for all the help!!!!!!!

Rich

[schutzen-jager]

could also be a case of excessive headspace !

[billyb]

My wife's dad had one hanging on the bedroom wall when we started dating. It was loaded then and the hammer cocked and on safety. That was in 1965. The hammer spring took a set and would not fire.my wife has the gun now and it would not fire. I replaced the hammer spring, cleaned the gun and it fires every time now. I would replace the hammer spring and see if that cures the misfires. Bill

[Wally]

You can do a "seat of the pants test" for head space...use a fired case and build up the bottom with a few layers of masking tape (trim around the rim so it doesn't extend past the rim) T...measure it's length w/o the tape the with ...two layers should prove hard to close the bold on it...keep adding tape until you cannot close it--then measure--subtract the orginal case length and you will get the head space amount--approximately... I bet that is not the problem...

[Wally]

My wife's dad had one hanging on the bedroom wall when we started dating. It was loaded then and the hammer cocked and on safety. That was in 1965. The hammer spring took a set and would not fire.my wife has the gun now and it would not fire. I replaced the hammer spring, cleaned the gun and it fires every time now. I would replace the hammer spring and see if that cures the misfires. Bill

I think that Bill has answered the question...

[Longhunter1757]

I'll try the headspace test tonight and I sure hope that's not the problem.

No hammer spring on this one billyb. It's a bolt action and I've already replaced the springs.

[docone31]

Fixing the head space is not a big deal. That was my first thought also.
Just strip the bolt to where only the area where the case head rests, take a measurement, then with a disc sander remove just a touch of metal. Keep the bolt square.
Won't take long, and just remember you cannot replace it without effort.
My 10/22, I headspaced to .042, they come from the factory, at least mine did with .055. Lots of misfires. A couple of bumps with the disc sander, and it was done. With my Ruger, I also pinned the firing pin. That helped also. The firing pin would drift up sometimes.
Just go slow on headspaceing. You can also go to RimfireCentral.com. They might have information also.

[popper]

With the trigger group removed, make sure it goes ALL the way into battery. The receiver is alum, some times it gets rough and a weak spring won't force it into FULL battery.
Check the hammer pivot is not chewed up and is clean. The new firing pins are only .005 longer. You've already replaced the recoil spring, make sure it isn't kinked. You can put a small washer under the hammer spring to see if it is weak. That one has the dog-ear hammer, check to make sure the hammer FULLY hits the firing pin when in battery. I had one that would fire a manually cycled round, but not the next one. Finally played with it and got 1 FTF per mag.

[doubs43]

If the firing pin is flat, lay it on an anvil and peen the end that strikes the cartridge rim with a hammer to lengthen it a few thousands of an inch. I had to do that to a Winchester Model 69A that had the same problem.