I have a JM stamped post crossbolt safety 336 30-30 that recently misfired. When the barrel is pointed up it will strike the primer but to light to fire it about every other shot. Level or pointed down it goes off every time. Any ideas?

Had a Franchi AL48, 28 gauge, that developed a soft strike and wouldn't fire.............. Cleaned the trigger group, mostly removed any oil, then lubed with a little graphite and it fired every time................

That's my thoughts on it!

that, or always shoot downhill....

Thats my first thought is that dirt and stuff has gummed the firing pin. I think I'm going to take it to a gunsmith to do it so I don't miss anything.

Unfortunately you cannot et a new hammer spring right now.
I have found that if you reload, the Fed 210 primer is softer than others. Win LR is good, but Rem and CCI are hard.

The bolt is easy to remove in a Marlin. I remove mine periodically and spray the firing pin channel with Gun Scrubber. I do not lube the internal parts as it attracts dust and grit.

That was my first though and replaced it with a new one, no change.

You got the two piece firing pin thing going on. Problems there?

schematic

Look first at the main hammer spring

switch one from another Marlin

I've used Wolfe aftermarket springs...action will run smoother....but

You may experience light primer strikes

The main spring was the first thing I replaced as I had a new factory one on hand. No change. Could very well be the two piece firing pin. Any idea how to tell if thats it and whats the fix?

Also, are there any disadvantages to a one piece firing pin, mainly safety?

The one piece firing pin overrides the design that prevents the gun from firing out of battery. Unless you have reloads not sized properly I don't see an issue. I never had an issue. I stil have one from a 1895 but never bothered to put it in an of my Marlin levers since I sold that one.

I re-read your original post about the problem and gu position. The rear section of the two piece firing pin drops down out of alignment with the channel when the gun is opened. It would seem that it is not being pushed back in alignment when action is closed. Due to wear of maybe something under the spring in the that pushes down on the rear section of firing pin in the bolt
https://www.youtube.com/watch?v=MGJcPVSHOAw

Thanks for that video. I think it may be something in the lever that isn't allowing it to lock up and place the firing pin in the correct spot when its pointed up. I'll post here when I figure it out..

My Texan suffered from an occasional misfire. I took the bolt apart and cleaned the internal parts to remove any residual oil and dried carbon. Problem solved. You should hear the FP slide as you rotate the bolt up and down.

My 336rc 30/30 wouldn't consistently fire Remington or winchester factory loads nor reloads. Tried all the usual fixes and nothing worked. Then I tried federal factory loads. Went through the whole box and no problems. Then tried federal brass and primers and no misfires after 15 rounds. Hope

Clean the bolt/firing pin, best thing i found is blow it out with compressed air from my air compressor quick and it works to get
oil and crud out esp. before it gets cold out. Shouldn't have to worry about which brand of primer you use. If you do it's time for a cleaning.

Yup, I had FTF's with CCI 200's in my 336 and Guide Gun. I switched to Federal 210's and no more problems.

If you have a hammer spur, take it off and try shooting without it.

If it is too weak to set off a primer, I think it has to be something in the action.
How old, how long have you owned it?
How much has it been shot?
Have you already disassembled and cleaned the action.
How far does the firing pin stick out through the face?

Question is whether it is spring force vs pin travel.

I'm late to this discussion, but assuming you cleaned out the firing pin channel and the problem persists, get the headspace checked.

Yup. They slow the hammer down

I bought a near new 336 made in 1969 that had lived in the JM vault until the Remington takeover around 2010(?). No ignition problems at all.
So unless the hammer spring seems abnormally light, indicating that a previous owner has shortened it too much, that is not the problem.

One test that you could try is to cycle the action and then try pushing the firing pin forward with your fore finger. Because of the safety spring acting on the rear section of the firing pin,
this will normally require about a pound or so of pressure. If it is significantly more difficult to push forward then the firing pin channel is gummed up or a burr exists on the firing pin.
Also possible is that the firing pin is broken or that a burr exists on the breech bolt where the rear part of the firing pin presses against the forward portion.

This ^^^^^^^^^^^^^^