My Marlin 336 30-30 is doing something weird; light primer strikes

[C. Latch]

A couple of weeks ago I was shooting my Marlin 336 in 30-30 and got some light primer strikes; the primers were dented but they didn't fire.

I did some googling and found repeated references to dirty firing pins and firing pin channels. So. Friday night, I removed my firing pins (front and rear) and cleaned the channel and cleaned the pin. Honestly, none of the assembly was notably dirty.

Yesterday I loaded several rounds into the rifle and went to shoot a few, offhanded, just to see if they'd shoot. Some did; some did not. Here's what I have ended up with:

-20 rounds of my brass was fired as new ammo (Federal Fusion) in this rifle, then reloaded; these reloads fired fine.
-I loaded about 40 rounds using some once-fired brass I bought in the S&S forum. Of this ammo:

-Roughly half was loaded in Federal or R-P cases, and every round fired fine.
-The other half was loaded in Winchester, Hornady, and Prvi cases; out of about 8 rounds fired, I've had 4 misfires; none fired after repeated attempts to fire them.

All of these reloads used Tula LRPs and either 2400 or IMR4227; the misfires all came with 4227; all of those rounds were loaded at the same time. The powder was dry and the Tula primers have been trouble-free in everything else I've used them in.

The only variable that appears, at this point, to be causing problems, is brass; two brands work fine; three others are giving problems.

While the firing pin appears to be free to travel as it should, and seems to fall hard enough to cause ignition, the pin itself seems to be rather short; on the misfires, the primers have what appears to be a fairly shallow indention, but it gets (slightly) deeper with each new attempt to fire them.

It seems that I have three directions to go here:

1) get a new mainspring or find a way to increase the tension on the existing one
2) get a longer firing pin
3) measure primer pocket depths

Which one should I start with? Or could I switch to large PISTOL primers, in light of the fact that I'm loading fairly light loads (no more than 21 grains of IMR4227 thus far, behind a NOE 311-165)?

[Bob in Revelstoke]

I am glad someone else is having the same problem as I. I have a marlin 336 which I bought in 1954. I blamed the problem on the rifles age and possibly a week spring. I was using CCI
primers. I changed to Federal and then Winchester. But the problem is still there. The firing pin indents the primer but not enough to set it off. Repeated strikes seem to work most time, but others are a complete fail to fire. I hope someone has an answer.

[JesterGrin_1]

It could be several things of which I am sure others may chime in with some time.

But I would make sure the Firing Pin channel is clean as well as the firing pin with a little light oil. No heavy oil so as to not slow down the action of the firing pin. The other might be a Weak Hammer Spring. To see if this is so of which is easy is to simply remove the stock and spring and add small washers to increase the hammer spring strength. If this works you can purchase a New Factory spring or leave it with a few washers on it. Just my idea of two things to check that are simple and cheap. :)


A little more information CCI and Tula primers have a pretty hard cup of which means you need a pretty good hit for dependable ignition. Federal Primers are the easiest to Ignite. This is why when people do action jobs and light springs they use Federal primers.

Do NOT use Large Pistol Primers in Rifle cartridges. They are not the same size between Large Pistol and Large Rifle plus Rifle Primers are designed for Higher Pressures.

As far as a replacement Firing pin you would have to look up the factory length and then compare that to what you have now. No need to spend funds on something you may not need.

[Tom Myers]

Have you checked the rim thickness of the cases that fire against those that fail to fire?

[C. Latch]

Federal Primers are the easiest to Ignite. This is why when people do action jobs and light springs they use Federal primers.

A local shop that I buy powder from at times, has Federal primers in stock......but do you have any idea what my wife is going to say when I try to explain to her that my existing stash of primers isn't enough? :lol:


Do NOT use Large Pistol Primers in Rifle cartridges. They are not the same size between Large Pistol and Large Rifle plus Rifle Primers are designed for Higher Pressures.

I thought they were the same size?

I don't think my 30-30 loads are any higher pressure than the ruger-only .45 colts I load with pistol primers.

[C. Latch]

Have you checked the rim thickness of the cases that fire against those that fail to fire?


Will put that on the list of things to check.

[M-Tecs]

The Tula primers are slightly larger so they tend to seat harder. Then anvil is also flush and not proud like on the US primers. If they are not fully seated misfires are common. On a US prime if it is flush or slightly below flush you don't have issues. With the Tula if the primer is not fully seated you may have issues.

[Pb2au]

Good call on the primers. I would see if the OP can get some 'murican primers and retest.

[trapper9260]

I am usen Win primers and have no problems of firen .All the one I did was ok.If that will help someone .I use mix brass also.Also what M-Tecs stated sound like could be the problem.

[Tom Myers]

I thought they were the same size?


Large rifle and large pistol primers have the same diameter (+/- 0.210") but are of different lengths.
Large Pistol primers ~ +/- 0.120"
Large Rifle primers ~ +/- 0.130"

[Bloodman14]

http://castboolits.gunloads.com/showthread.php?124990-Marlin-336-firing-pin&highlight=marlin+firing+pin

See this thread. It may help.

[Bullshop]

Rear firing pin alignment can sometimes be the problem. In some cases there will need to be an adjustment made. When the hand lever is in the full closed position with some pressure against the lower tang the rear firing pin extension ( Marlin safety) has to be level to get the full throw length to the firing pin proper. If with the hand lever at this position the rear firing pin is not level either past center or short of center it will cause a too light firing pin strike to the primer.
To check it you can remove the lever but leave the bolt in place. Push up on the protruding button at the bottom tang and try to watch the rear firing pin in the bolt and see at what point in the travel of the button in the bottom tang is the rear firing pin in a level position.
That is the position the rear pin needs to be in with the hand lever at the at the full closed position with a bit of squeeze applied to the lever.
You can bypass the whole Marlin safety two piece firing pin system by going to the model 36 type one piece firing pin. BBBUUUUUTTTT!!!!
If you do the rifle can then fire before it is fully closed and locked up which is the reason for the Marlin safety two piece firing pin.

[JesterGrin_1]

You do not need to run out and purchase Federal Primers. Just increase the hammer spring pressure with Washers that will enable you to give good Firing firing pin hits to the harder primers. I also smooth out and polish the rod off of the hammer that the spring goes onto. And as said make sure your primers are seated correctly. I had an RCBS Hand Primer that would not seat them all the way. It took me awhile to figure out it was not me but the Hand Primer lol. RCBS replaced it at no charge.

I really think that checking rim thickness of the different manufactured cartridges to be a bit of a reach.

[robertbank]

You do not need to run out and purchase Federal Primers. Just increase the hammer spring pressure with Washers that will enable you to give good Firing firing pin hits to the harder primers. I also smooth out and polish the rod off of the hammer that the spring goes onto. And as said make sure your primers are seated correctly. I had an RCBS Hand Primer that would not seat them all the way. It took me awhile to figure out it was not me but the Hand Primer lol. RCBS replaced it at no charge.

I really think that checking rim thickness of the different manufactured cartridges to be a bit of a reach.

This, along with ensuring you are seating your primers fully and not using large pistol primers. Both will cause what appears to be light primer strikes when in fact the firing pin is just seating the primer or can't fully reach the primer in the case of using LPP.

Take Care

Bob

[popper]

My 336 has always shown 'light' strikes with CCI LR, only ones I use. A few FtF, usually bad seating due to crud in the hole. I set my die to HS on the shoulder. It seams to be a common problem with the 336 I suspect it is a worn lever from jacking the round into the lands, i.e. 2 piece pin problem.

[Freischütz]

I have a New Model Marlin 45/70 that I purchased in 1972. I had problems with light firing pin strikes. The authorized repair shop said my rifle's firing pin was short, and they replaced it. No problems after that.

[Walter Laich]

I had a similar problem where all of a sudden I was getting light hits. turns out the SDB press main lever was cracking and rather than fully seating the primers was bending instead. Call to Dillon got a new one in the mail in less than a week.
Problem is solved.

[C. Latch]

I loaded some more ammo for my 30-30 yesterday. It occurred to me after the fact that while I was careful to seat the primers fully (I'm always careful to do that, really) it was probably irrelevant, as all my empty brass has already been fired in this rifle anyway, and hopefully won't give any further problems.

[OverMax]

MO: Every lever rifle over time needs its action cleaned. I personally know of 2-fellows who are extremely hesitant to take apart their Marlins action. So upset with the idea they might not be able to get their rifle put back together correctly. They are aware as I. Dirt, powder fouling and solvents compact in such places where it may gum up or interrupt a rifles internal workings. I don't know if cleaning up a lever rifles internal action parts will make my rifle shoot better. It is comforting to know when in the field when I squeeze the trigger on my 32 Special its far more likely to fire than not.

[hp246]

When I was a kid (late 60s early 70s) this was a known issue with Marlin firing pins. My recollection is that Marlin repaired these at the time. Might want to check with Marlin.

[ba_50]

Hi,

I know this is an old post but a good one and wanted to reply to the post about one-piece firing pins being unsafe. My 336 has that problem and I believe I will go with a one-piece firing pin.

Swaney, over on marlinowners.com tried to make his go off with the bolt partially open and was unable to do so. If there was a liability problem, the firing pin business would be gone by now.

[Geezer in NH]

My Dad and 3 nephews had 30/30 Marlins bought the same year by him, only dads would not fire reloads consistently. His rifles front Firing pin was shorter. I turned a pin the same as the other guns and presto fully reliable. For what it is worth. (used my 30-06 700 rem BDL)