The dreaded Marlin "Jam"

[waco]

Ever had this happen? Sucks huh? Here is how to fix the problem for good.
https://www.youtube.com/watch?v=0CK_Hf-OJWo

[longbow]

What a coincidence! I decided today to get back to my Marlin 1894 because it has been, well, jamming!

Actually it started some time ago and wasn't really bad so I left it and occasionally had to take it apart to clear a cartridge out. However, a few years ago I was given a Mihec H&G #503 SWC mould but the rounds loaded with H&G #503's wouldn't feed reliably ~ no surprise because neither did Lyman 429421's.

Any SWC would tend to tip up and jam against the breech face. RNFP's even with fairly large meplat didn't. Really, I am not sure why but SWC's were the worst and they would often jam the meplat against the breech face or the shoulder but either way they would not feed well plus the irritating jam was till there.

During my research phase I also found out about filing the cartridge stop back to allow longer OAL which I though might help with SWC feeding but it did not. It simply allowed longer cartridges to feed... or jam!

info on that here:

http://castboolits.gunloads.com/show...-cartridge-OAL

I decided that since some Marlins will feed SWC's okay and some won't mine was moving to the first category of "will feed SWC's". So, I read some on the Marlinowner's forum and learned a bit but when I looked at my feeding problem it was mostly the rounds tipping up quite high so jamming the nose against the breech face. I took the carrier out and modified it by filing (no Dremel!) until the loaded rounds didn't tip up so high and that worked... except now I started getting the "feeding 2 through" jam! No winning here!

Again, it was intermittent so I put up with it and wasn't using the Marlin much at the time.

A little while ago I started checking Marlin jam fixes and found this:

http://marauder.homestead.com/files/Marlin94Fix.html

Good info and as stated better than simply replacing the carrier.

So, back to my Marlin jam "letting 2 through".

While my carrier does not appear to have the peening damage, I filed the carrier so lowered the nose. DOH! Never occurred to me!

So I looked at the info again and something I had missed before was step 3:

3) Bend the carriers' nose up about .05".
Use the heat and bend method described below.

Clamp the carrier in a large bench vice so the pivot hole axis runs vertically. The two parallel faces at the pivot hole end need to be clamped in aluminum blocks for a heat sink. If the heat gets to the plunger spring you will need a new carrier, so the heat sinks are very important.

Heat the neck just behind the front of the carrier till dull red. Position a block of steel (or brass) just behind the shell stop (tang that hangs down in front) and tap the head "up". This is actually going to be parallel to the floor.

Measuring this movement can be difficult. I gave up trying after the first few and now it’s by eye. After cooling try it in the gun. If you went too far the very first incoming shell will jam as the lever is opened; the carrier will wedge it up against the top of the magazine opening. You will need to heat the carrier again and tap it back a touch.
This retimes the carriers' initial pick up height to let one round in and keep the rest in the magazine.

I didn't want to heat my carrier so decided I would try soldering a piece of old hacksaw blade to the ramp with the intent of preventing the peening, and lifting the nose of the carrier a bit. It appears to have worked! I have just cycled several rounds through the gun with no hint of jamming. YAY!

Now to load up some of the offending SWC's and try those, especially the Lyman 429421 which is both SWC and longer OAL than stock Marlins want. Good excuse for a range day to try my longer heavier jam prone boolits of which I have three or four types the gun has not liked in the past.

Hopefully I have it solved but also, note that there is more than one type of Marlin jam and more than one way to fix them.

And another thing, I can remove my carrier much easier than as shown in the video. I remove lever, bolt, ejector, carrier pivot screw then simply push the carrier up, tilt it towards the open side of the receiver and lift out. No other disassembly required. Takes about 2 minutes.

Some good info here too:

https://marauder.homestead.com/files/TUNING_M_1894.htm

Longbow

[W.R.Buchanan]

LB: I have posted the fix for this a bunch of times here at Castboolits. No need to do anything to the carrier as long as it isn't worn too much.

All you need to do is file a .030-.040 radius on the lifter cam on the lever. That takes the wear point out of the mix. Some vaseline works well for a lube,,, or anything else that is slippery.

As far as feeding SWC's I have posted pics of that a bunch times here. A .040-.050 chamfer on the chamber mouth fixes it so it won't gouge into the boolits when feeding . Mine feeds anything as fast as you can run the lever. All I shoot in that gun are SWC's.

Randy

[longbow]

Randy:

Yes, I have seen your post. I wish you had posted before I went to all the trouble though I am not sure your fix would have totally addressed the issues my gun had. SWC's didn't just hang up a bit, they hung up a lot. They seemed to tip up too high so I reshaped the carrier some to address it. RNFP's with small meplats ran perfectly but try with an SWC and they hung up at shoulder and sometimes right on the meplat as in not even starting into the chamber.

Strangely my carrier looks a lot like the carrier shown in the link now. That fixed feeding of SWC's but... made the dreaded Marlin jam worse! I just recently soldered a chunk of hacksaw blade to the bottom of the carrier and that seems to have raised it enough to stop the jam but... of course it will take a bit of loading and racking rounds through it to be sure. The hacksaw blade will solve the peening issue as well.

Should I have any further feeding issues I will follow your advice before doing anything else! Like I said, had you posted it before I did the work I would have tried it first. I did the initial work several years ago. If your fix solved the problem then it is an easy fix and if not it certainly wouldn't take long and doesn't do any harm. Probably a good thing to do anyway and I just may add it to my long list of mod's to my Marlin regardless. A little prevention maybe!

Seems odd to me that such a simple mechanism is so picky but I have to think that timing is quite critical and possibly extreme tolerances (or machining out of tolerance maybe?) causes grief. Some guns seem to run fine with everything and some seem to be picky which is what strikes me as odd for so simple a mechanism with so few moving parts.

However, many complain of the dreaded Marlin jam so it isn't just me.

Longbow

[bikerbeans]

Usually the marlin jam on the 1894 is from the sharp edge on the tip of the lever gouging a divot in the carrier. Gently removing this sharp edge before your 1894 double feeds is a good idea.

BB

[longbow]

Mine had a very slight, and I do mean very slight, divot in the carrier but was feeding 2 thru sometimes. I wouldn't have thought they'd be that sensitive. It has been used but has not seen an extraordinary amount of use.

It didn't like Lyman 429421's but not only are they SWC's they are too long in the nose which I didn't know at the time I got the mould. I got "the best" Keith style SWC boolit mould recommended by one and all... except that recommendation was meant for revolvers not Marlins. I didn't have too much trouble with it at first with just an occasional hang up but I had to operate the gun "briskly".

Anyway, I never did get any decent accuracy with that boolit regardless so made a mould to cast larger diameter and 265 gr. RNFP. That worked so I used it. No problems for quite a while, then I was given a Mihec H&G #503 brass mould which is so beautiful I wanted to use it so I read up on getting Marlin's to feed SWC's at which time I do not think I was even a member here but if so I had not seen Randy's post or I would have tried that first. By this time I was getting the feeding 2 thru issue plus not feeding SWC's. I worked on the carrier and got it to feed SWC's but the feeding 2 thru got worse so I put the gun away for a bit.

I recently re-read the marauder.homestead info and realized when I modified the carrier I had lowered the front edge. Aaaahhh! The light came on, dimly but it came on. I had missed the bending the nose up by 0.050". So just added a piece of hacksaw blade on the bottom where the divot forms and ran a couple dozen or more rounds from the magazine and all worked flawlessly.

Maybe I have it fixed finally. However, if not I may just buy a new carrier and apply Randy's fix to the chamber mouth to see if that does it. If so I am good! If not then I'd repeat a little of the modifications but maybe not so much!

Filing the cartridge stop back was one thing that worked well so now I can run quite long rounds through the gun.

My little Marlin might not be a bad bear gun loaded with 270 to 300 gr. boolits... if it will feed dependably anyway! I'd hate to have it not feed when needed so that a bear got to feed on me!

I've never gotten decent long range accuracy with heavy boolits over 270 grs. or so but they fly pretty well to 50 yards and any bear issue would be closer than that so it should be fine. I'd rather use a .45-70 or 12 ga. round ball for bear protection though.

So back on track... If I have to do this over again, it is Randy's way first. If that does it then it is simple and effective. I will also file that radius on the lever cam. If it works as is then no need to file a radius because that hacksaw blade will be harder than the lever. I shouldn't be bothered by a divot again.

I'll note as always... nothing is ever easy! Well, if you don't see Randy's solution first that is.

Longbow