[375Win]

the Marlin jam ..... another go at it

OK, here's the story. My pal recently bought an old but like-new barely-shot Marlin lever in .44 Magnum (maybe 1970 vintage ??). I took "everything" apart and cleaned it and lubed it. I've studied the several Jam posts here at MarlinForum and I inspected all the places which might be worn where The Jam would occur: since the rifle is new, no wear marks, I don't see any mechanical problems.

After cleaning and reassembly, I loaded in 6 new lead-bullet cartridges. And with the very first cycling of the lever, The Jam occured. I was able to force-out the jammed cartridge, and everything then worked just fine after that, the remaining 5 cycled without problem.
-- I reloaded the 6 new lead-bullet cartridges .... first cartridge again jammed, etc.

SO, I try something different. I loaded 6 new lead-bullet cartridges, but, when I loaded in the 6th cartridge I gave it a good shove far into the magazine with a brass rod, then withdrew the brass rod. And good news: all 6 cartridges cycled without problem. I did this 4 more times, no Jam.

OBVIOUS QUESTION: why does shoving the last cartridge further into the magazine (apparently) prevent The Jam from happening ?? I've stared at it but cannot figure out the mechanical system answer to this.

Any ideas ??

Cheers and Thanks,

Carl

 

[JBledsoe]

Re: the Marlin jam ..... another go at it

.

Hi Carl,

Can we start with something a bit easier? ;D ;D

I have experienced the same thing but never found the answer other than the fact that the last round is not getting pushed in far enough. Sooo, when I load I push the last round in with another round that is push in about half way and then withdrawn. Problem solved, not cured but I live with it. We can wait to see who has an answer if there is an answer.

 

[375Win]

Re: the Marlin jam ..... another go at it

hey, no kidding, your response is very encouraging: it's not just me that "sees" this happening with a particular rifle. YES, I also did the same as you: use a cartridge to shove in the last round, with the same results as using the brass rod.
-- "Obviously" it has to do with what happens when a "completely pushed in" cartridge exits the magazine tube during the lever-cycling action.

OK, to my engineering mind that tells me that there could be a Marlin design issue in play here that affects "every" such rifle. Or maybe it is just caliber-specific to the .44 Magnum ??

Anyway, I'm hoping someone has The Answer.

Cheers,

Carl

 

[Griff]

Re: the Marlin jam ..... another go at it

Like all our leverguns, they're a little (or a lot) OAL sensitive. You're probably runnin' your's at the limit of tolerances. Now I'm just speculatin' but, your "last" cartridge isn't pushing your "next to last cartridge" far enough to completely clear the carrier and/or frame; and what with the spring pressure of a full mag, one or more may be slightly off line... shortening the stack.

The Marlin lifts the carrier on the levers "backstroke" so the empty has time to clear the port; that timing is critical in both allowing the round on the carrier up and to block the following round from slipping into the action early.

There's 2, 3 guys on the SASS Wire and one on Levergunners Forum that know the 1894 inside, front & back. Ask yer question there and if you get an answer from "Spur Roberts", "Adirondak Jack" or "Widowmaker Hill", you can take it to the bank.

IIRC, it was SR that helped AJ get his "Cowboy 45 Special" to work in .45Colt Marlins. Basically an ACP length 56 Colt, but with correct case mouth dimemsions. Ant or all three may visit here, but I'm sure they spend more time at the other sites.

Also, check out Marauder's excellent Rifle Tune Ups site for making yer cowboy guns slicker'n snot on a Louisiana swamp!

 

[375Win]

Re: the Marlin jam ..... another go at it

WOW, more great info, Thanks Much !!!!!

Cheers,

Carl

 

[Leverdude]

Re: the Marlin jam ..... another go at it

Thats not exactly correct. OAL isn't normally critical, the lifter cuts off the mag on the opening or forward stroke but lifts the carrier into its upward position on the backstroke. When the tube is loaded you should see a case rim right there at the loading gate. As you open the action that one should slip into the action being pushed by the rest in the tube, as its moving into the action the lifter comes up slightly & blocks the next one from coming in. If that first one does not fully enter the action before the lever is completely forward it'll jam because once the lever is fully forward the lifter must lift or the lever cant move, if the cartrige isn't fully into the reciever the lifter cant lift. In a poorly timed gun OAL can matter to some extent in preventing 2 from coming into the action because the lifter doesn't block the tube in time.

After the lifter is up the tab on its bottom front edge is still blocking the tube, as you close the lever the bolt pushes the round into the chamber and the lever pushes the lifter back down, as the lifter falls it opens the tube again & the next round is pushed under spring tension into the action until its rim reaches the loading gates front edge. It kinda "thunks" into place as soon as the lifter drops, you will feel it if you go slow. Thats why pushing the first one further in & then releasing it will sometimes let the first one feed. When you push it thru the gate that round isn't pushed into position with authority like sucessive rounds will be. I'd check & see if the tube isn't dirty or gummed up, also there might be something on the edge of the gate thats keeping that first one from following the lever into the action too. The following rounds slamming back into position might make it by a burr or something that the first one hangs up on. When you look you should see the rim at the front of the gate, the opposite side of the rim is against the lever inside the gun and the round simply follows that back, slipping by the gate, as the action is opened.

Theres alot of info in our reference library that may be of some help. I believe there are cutaway drawings of an action in battery, mid cycle & fired positions, its a 336 but functionally they are the same.

Its a design issue to a degree & more often problematic in the straight walled pistol rounds because theres less difference between body dia & rim dia. The lifter on the opening stroke needs to come up just enough to block the rim of the next one while leaving room for the current round to slide freely from the tube. Back in the late 1880's when LL Hepburn was perfecting this design for John Marlin there were no really straight walled cartridges. Most were tapered and or bottlenecked. Cases like these leave you more room to play with because as the case is entering its also getting thinner. Thats why this is a much more rare issue, almost unheard of, with the calibers it was initially made for such as 32/40, 38/55, 44/40 etc. It happens but very rarely. The most common seem to be the 357, 44 & 35 Rem.

 

[swany]

Re: the Marlin jam ..... another go at it

One thing you should do at this point is try an easier maybe.

Remove the mag tube and carefully check it for burrs near the action end of it. Make sure the tube is clean (you just never know if there is a machine metal chip in there. Newer ones with the molded plastic follower have had defects in them. If you have a quality control problem that got through the process it may be something easy to fix. I have had jams caused by a very little patch of rust causing a lag in the mag tube causing a jam.

Good luck.

 

[375Win]

Re: the Marlin jam ..... another go at it

Swany,

Thanks Much for the additional info.

Yes, I did remove the mag tube and swabbed it out nice and clean, then gently 2,000-grit sandpaper'ed the inside of the tube at the receiver end to remove any possible burrs. Sandpaper'ed the metal follower. Sandpaper'ed all the lifter surfaces over which the cartridge moves. All sliding surfaces are clean, very smooth, and rust free.

Cheers,

Carl

 

[JBledsoe]

Re: the Marlin jam ..... another go at it

.

Well..........?? Did that solve it?

 

[375Win]

Re: the Marlin jam ..... another go at it

JBledso,

did cleaning the mag tube solve the problem ?? nope.

In my original post I'd mentioned taking apart "everything" .... the mag tube was part of that disassembly and cleaning.

And as noted by yourself and Griff and Leverdude, there's "something" happening in there that gets solved by shoving the last cartridge "further" into the mag tube, then letting it move back against the loading gate.

Therefore, the fundamental question remains: what is that "something" ?? I wish I had an x-ray machine so I could watch all the parts move.

Cheers,

Carl