Miss Firing 336

[flyingstick]

My Marlin 336 is miss firing about 1 out of every 9 shots. I first thought it was a bad lot of primers so I changed from Winchesters to CCI. The same problem. I ordered a Hammer spring for it and just knew that would fix it, nope. Ordered a new firing pin, still does it. It's just not hitting the primer hard enough. I can recock and fire again and then it will go off. I've cleaned this thing spotless. Any ideas? this has got to be fixed before hunting season.
Don:coffee:

[Dr. A]

I had the same problem on a 1951 336 and thought it was the hammer spring. There were two positions however, for this trigger spring. So it could have the variable strike power I would guess. The hammer spring plate actually had two possible positions. I merely moved the hammer spring plate forward to the front position. Not sure if this applies to your gun or not.

[NVcurmudgeon]

I had a (new) 1895 with the same trouble. It turned out to be a burr on the rear firing pin.

[jtaylor1960]

In an older gun I would say the firing pins are worn or broken.Is there a good dent in the primers ? My 1895 only missfired once on a cartridge that made it hard to close the lever. Are your shells sized so that they chamber easily?Thats's the easy stuff I can think of .Hope that helps. Jeff Taylor.

[woody1]

Reloads correct? Are they perhaps not fully chambering and the first strike seats them fully? Same with the primers. Are the primers fully seated or is the first strike seating them and the second fires. Do you have a good dent after the first strike? Headspace? Do the fired primers protrude after firing with a full power load? If so, there's perhaps excessive headspace the the firing pin doesn't quite reach. No answers, just stuff to check on. Is the chamber clean? Firing pin - new one, the front one I assume. Did you check the rear firing pin. Perhaps too short from wear. You did clean the bolt well when you had the firing pin out? Still no answers, just stuff to check on and eliminate. Regards, Woody

[Char-Gar]

If you have changed primers, you know it is not the primers. If you have put in a new spring, you know it is not fatigue on an old spring. If you put in a new firing pin, you know it is not a worn firing pin. What does that leave?

The first thing that comes to my mind is headspace. The primer is far enough from the pin that you are getting light strikes. That is one of the few things left to eliminate. I would think it is either headspace or something in the firing pin channel in the bolt that is preventing the pin from going full forward. I would make certain there is no old grease or oil inside the bolt and lightly polish the channel. It should be fairly easy to check the firing pin protrusion against specs.

[grumpy one]

Just to complete the picture, I had some misfiring from my 336 when I first got it, and dismantled the bolt, removing the firing pins, then pushed (by hand) a drill bit down the firing pin hole in the bolt from the back. Sure enough, there was a whole bunch of metal drilling swarf that had been pushed forward by the firing pin to the bottom of the hole. As it turned out my problem was actually bullet lube having contaminated a few primers, but I'm happier knowing that I no longer have that garbage restricting my firing pin's forward movement.

[Marlin Junky]

flyingstick,

Are your primers set too deep in the primer pockets?

MJ

[flyingstick]

Thanks guys for all your help. I'm going to recheck everything again. I'll let you know if I find the Culprit.
Don

[woody1]

Thanks guys for all your help. I'm going to recheck everything again. I'll let you know if I find the Culprit.
Don

Did you discover the problem? Inquiring minds want to know! I had another thought ... is yours the version with the push button safety? It IS possible to accidentally depress the safety a little and the hammer will still fall to firing position but will be hampered by the safety enough to make only a light strike. Something else to check mebe? Regards, Woody

[flyingstick]

Sorry Woody, I have'nt shot it yet. I'm planning on going to the range tommorrow. Sunday's are 18 hour days for me and our range is closed on Monday's. But I'll let you know how it goes.
And, no it does'nt have a safety on it. It is an old Revelation built by Marlin. I sent it back to Marlin this Winter and had a new 336 barrel put on it. The hammer just feels like it has a weak spring even though it's new. I've checked everything you guys have recomended but I have'nt found the problem yet. I shimmed up the hammer spring with a washer and it feels a lot tighter. I'll know more tommorow and report back.
Thanks again,
Don

[flyingstick]

I shot it today. Still the same problem. I'm going to disassemble the bolt again tonight. Would'nt Marlin have checked the headspace when they put on the new barrel?

[Bret4207]

Miss Firing 336? I dated Miss Frozen Food of Carteret County 1977, but your girl sounds much older.

(Carpetman missed this, so here I am to help!)

[flyingstick]

:-D She was about to be a Mrs. but if she won't fire she'll have to stay the Miss.

[woody1]

Did you have this problem before it was rebarreled? Doe sit misfire with factory loads? Regards, WOody

[Four Fingers of Death]

I had the same problem with my old 1866 Uberti clone. turned out it was a stretched frame. Don't know that that would be a problem with the 336. I'm just about to get my 444S into action, it's a 1977 model and has a few miles on the clock (been well looked after though). I might have to check it out.

[flyingstick]

Woody, It has been hanging on the shelf for 15 years. I just recently started shooting it again after the new barrel was installed. I have'nt been shooting any factory bullets through it. I did take the bolt out again today and remove the firing pins again to clean it and check for maybe a burr, but did'nt find anything. I loaded ten cases with just primers, they all went off. 6 of them are dented very deep but 4 are just barely enough to ignite. Headspace is tight. No slack there. Something is changing somewhere and I can't find it. It feels like the hammer hits something on it's way to the firing pin, but I can't find any burrs or wear signs. Thanks for you folks concern and input. I'll keep looking.
Don

[Boomer Mikey]

Check to see if the hammer is striking the sear on the way down, a rough or high spot interfering with the sear. This is a common problem in rifles with DIY trigger jobs where the sear is rounded off and the angles between the hammer notch and sear are wrong. Do the same test with primers and deliberately yank the trigger all the way each time. Check side play in the hammer and check for burs along the side of the hammer. Look for marks on the frame and on the side of the hammer where a bur is rubbing on the side of the hammer.

Boomer :Fire:

[BABore]

Your 336 should have a two piece firing pin. The rear portion is spring loaded and gets moved out of alignment when the finger lever is not fully closed. I'd have to look, but I think the locking bolt straightens the pin into alignment so the hammer has a direct strike. May want to check that out. Coincidently I'm running into the same ordeal with a 336 I just picked up. I ordered an extra power main spring from Wolff. If that doesn't cure it I may look at getting another 1-pc firing pin. I tore this gun down to the last screw when I got it. Everything seem fine. I've only experienced problems of late and the mainspring tension is half that of my other Marlins.

[John Taylor]

I have a 336 in for repair that is doing the same thing. So far I have found the lever bent very slightly which keeps the locking lug from going all the way up and causing the rear part of the firing pin to hit the breach block before hitting the forward part of the firing pin. This causes it to loose some of its forward motion and makes for a light hit to the primer. A simple way to check this is to close the lever and with the hammer in the full cocked position push forward on the firing pin and see if it slides smoothly or catches part way.

[flyingstick]

Turns out I have the same problem as John Taylor. I don't know if it was due to wear or a bent lever. I think just wear, but anyhow the locking lever was not pushing the rear pin up quite high enough. I did a little filing on the lever so it would close a bit more and Whala! Presto. You can see the rear pin straighten up at that last little close of the lever. Before you could'nt feel it catch if you just pushed the firing pin in with your finger but you could feel something that just was'nt quite right when it would misfire. Anyway I don't think I would have ever found it without your help. Thanks folks, She's become the Mrs. again:mrgreen:
Don

[John Taylor]

I'm thinking that someone tried to close the action on a tight round and forced the lever up, this one has been filed on already. The levers are not hardened and will bend so I just bent it back the other way enough to push the locking lug all the way up. The same owner has a late model browning 86 in with the same problem of not firing all the time. This one has a spring loaded plunger in the rear of the firing pin that the hammer hits. It will be interesting to find out what the problem is.

[Newtire]

Just to say that I got alot out of this thread. I managed to take care of my 336's misfire blues also. I got this rifle from a guy I know for $200.00 and found out why he sold it to me after it started misfiring.

I managed to make use of a 30-30 headspace gauge I got sold as an 8mm on E-bay awhile back. A no-go wouldn't go.

It turned out to be that the rear firing pin had a burr, the lever wasn't lifting up the rear section of the pin under the lever and the firing pin channel was pretty gunky. I Dremeled the pin burr, cleaned the bolt out and ground a bit off the lever to let it push the pin more.

I fired 15 rounds of primed cases into the garbage can in the garage and no misfires. gonna take it to the range maybe this weekend and see how she does.

that was a very informative bunch of tips. thanks guys!

[Marlin Junky]

Good advice in post #18 for a lot of 336 misfiring conditions. When a 336 action job consists primarily of reducing the cock notch on the hammer, the trigger sear can bump the hammer's safety notch on the way down during the firing sequence and the hammer looses a lot of it's energy. The remedy is to stone the hammer's safety notch out of the way of the trigger sear when the hammer rotates down toward the firing pin. The other common way I've noticed to create unreliable ignition in a 336 is to install a reduced power mainspring. The best way to do an action job is to decrease the full cock hammer notch and trigger sear engagement but not by stoning the hammer alone.

Anyway, I'm glad you got your 336 working again.

MJ