Is this the "Marlin Jam"?

[snozzberries]

Hello,

 

Brand new poster.  I was recommended to this site by a users from AccurateShooter.

 

I have a Marlin 1894 in 45LC. It's a couple years old. Ever since the first time I shot it, it's jammed. The next round doesn't make it all the way out of the feeding tube, before the lift tries to elevate it. As such it gets stuck.

All my searches lead me to this article, which talks about "letting 2 rounds in". It seems this is a different problem. http://marauder.homestead.com/files/Marlin94Fix.html

 

Is this the "Marlin Jam" as described?  Can I fix it the same way? 

 

[Widder, SASS #59054]

It appears your timing of the carrier is a little too fast....BUT, you can counter this effect with shorter OAL ammo.

 

If in fact your timing is too fast for that length of ammo, you can also remedy the problem by shaving off

a couple .000's from your carrier timing ramp.

 

P.S. -  your problem IS NOT the so called 'Marlin Jam'.   Actually, its the opposite of it.

 

..........Widder

 

[snozzberries]

Thanks for the info.  I'm reloading my ammo, so I'm sure I can shorten it.  Currently shooting Berry's 250gr bullets, 5gr titegroup, 1.595" OAL.  Looking at a round and there appears to be lots of space to shorten them. 

 

Do you think this a problem that will go away on its own, as the rifle wears in further?

 

Is there a diagram of the carrier timing ramp, and where I should shave it?

[Widder, SASS #59054]

Howdy Snozz.

 

Unless you shoot your Marlin a few thousand times, its unlikely the problem will go away on its own due

to wear.    

 

I'm not aware of a diagram of the carrier that will give you this info, but I will try to explain to you HOW and WHERE

to check and fix your problem, other than shortening your ammo.

Before I get into that info,  normally 1.595" OAL ammo for your rifle is not considered

very long.   Is it possible that someone has tried to work on that carrier?

Or is it possible someone has slightly bent it upwards to help prevent the 'Marlin Jam'?

 

Here is how to check your problem:

If you can use a dummy round, please do.

Take a 1.600 OAL cartridge and put into the loading gate.   THEN, try to cycle it thru the action.     

Hopefully, it will jam on you again and when it does, keep pressure on the downward stroke of the lever.

DON'T bend the lever with too much pressure but put some reasonably stiff pressure on the lever for just a few seconds.

 

NOW, take the rifle apart and look at the bottom of the carrier, where your timing ramp is located.

My guess is that somewhere in the lower 1/3 portion of that ramp will be a slight scuff mark.   This mark

was caused by your downward pressure of the lever and it was scuffed by the snail cam on the lever.

 

This is the area of the timing ramp that you would need to polish down..... BUT ONLY BY A FEW .000's.

By a few .000's, I'm talking something like only .005 or less.

 

BEFORE doing all this, please double check the problem by reducing your OAL ammo and making sure

that helps somewhat.  

 

Holler back.   Its 11:30 p.m. here in Tennessee and I'll probably still be up for another hour or so.

 

..........Widder

 

[The Original Lumpy Gritz]

Have you cycled any factory ammo?

Have you ck'd all screws for tightness? 

NO, that's not the 'Marlin Jam'.

Listen to Widder 

OLG 

 

[Widder, SASS #59054]

Lumpy always gives good advice, especially about those screws.

 

On a side note, I'm assuming these jams occur frequently.  If they only occur on the last round, it could be a 

weak or shorten mag tube spring or the follower being hindered from moving freely for the last round.

 

There is a VERY SLIGHT chance something could be obstructing your portal area.   This is the area 

of the frame between the mag tube and inside the receiver.

AND, although more rare, if your mag tube does not mate up well with the front portal entrance, a slight 'gap'

between the magtube and portal will catch the rim of the following rounds, which prevents it pushing

the preceding round onto the carrier.

All that being stated, I would still put my money on the 'fast timing' of your carrier ramp AND/OR 

you ammo is too long for your timing.

 

If you can call me from Canada, feel free to holler:   865 / 696-1996

 

..........Widder

 

[snozzberries]

I'll get a case prepped and load up a dummy round to 1.600" so I can test.

It occurs every 25th round or so.  (Just guessing)  When it does occur I have to loosen a bunch of screws, so it's a giant PITA. 

Nobody has tried to work on the carrier, I bought the rifle brand-new and I haven't done something that would impact this. 

Yes I've cycled factory ammo, I bought 2 cases of Fiocchi so I'd have brass to reload.  Factory rounds have the problem too.

Some of the screws absolutely come lose, and then it happens much more often.  Said another way, when it happens, there are usually loose screws.  Last time I assembled it I used some loctite to prevent them from backing out, and it still jamed.  So loose screws is not 100% the problem. 

It's not the last round, happens randomly including in the middle of the magazine.  (5th round)

I expect the mag tube spring is fine since it's only a couple years old.

I'll take a look at the frame and the mag tube. 

I'm not in Canada, I'm in Washington.  Apparently my Public IP is Canada. 

 

Sounds like my next steps are I'll get the rifle disassembled, clean all the parts, take pictures of them, inspect the mag tube mating to the receiver, load up a dummy round, and then see if I can repro it. 

[The Original Lumpy Gritz]

Post up pictures of the carrier.

Use blue Loctite #242. Just a very small drop......

Look for rough machine marks and sharp edges where the cartridge passes through the rec'r from the mag tube.

If you have the plastic magazine follower, get a metal one.

OLG 

[The Original Lumpy Gritz]

What's the OAL of that factory ammo?

What's the bullet shape/profile of this factory ammo?

OLG 

[Sedalia Dave]

Closely inspect the inside of the mag tube for any signs of corrosion. If you find any wrap a little 4 ought steel wool around a brass cleaning brush. Chuck the cleaning brush rod in a drill and polish just enough to remove the corrosion.  Follow up with a bore mop coated with a high quality car wax and polish the inside of the mag tube till it shines like a mirror.

 

Replace that plastic follower with a brass or stainless steel one. Steve's Guns sell a Stainless Steel replacement.

 

BearTooth Mercantile sell both brass and Stainless steel versions

 

[Widder, SASS #59054]

1 hour ago, Sedalia Dave said:

Closely inspect the inside of the mag tube for any signs of corrosion. If you find any wrap a little 4 ought steel wool around a brass cleaning brush. Chuck the cleaning brush rod in a drill and polish just enough to remove the corrosion.  Follow up with a bore mop coated with a high quality car way and polish the inside of the mag tube till it shines like a mirror.

 

Replace that plastic follower with a brass or stainless steel one. Steve's Guns sell a Stainless Steel replacement.

 

BearTooth Mercantile sell both brass and Stainless steel versions

 

Thats very good advice.  

 

..........Widder

 

[bgavin]

Subscribed.
I really enjoy this tutoring about the Marlin action.

[Cheyenne Ranger, 48747L]

has your rifle done this from the beginning or has it increased in frequency as time passed?

 

a good cleaning always is a good idea

 

At our club we've had folks will all the screws loosened and the rifle still ran OK.  Marlin should include screwdrivers with each 1894 they sell

 

 

[snozzberries]

My rifle has the stock follower (it's red), so I expect it's plastic.  Is there a preference of Brass or Stainless Steel for the follower?

The rifle has always done this, from the day it was brand new.  6 rounds into the very first time I shot it, it did this.

I put all the parts through the ultrasonic cleaner, I have not oiled any of them yet.

Let me know if you want more pictures.  I haven't loaded up a test-round yet.  Need to deprime some brass first.

Factory ammo on the left, my reload on the right.  Factory ammo is 1.555", so mine is obviously longer.

Looking at the mag tube, and entrance in the receiver, they both don't seem to have any sharps jagged edges.  It looks like the magazine tube entrance in the receiver isn't perfectly round.

Parts collection

You can see it was getting a cut in the carrier.  I slightly rounded the edge on the lever.  (This was from the "marlin jam" websites recommendation.)

Carrier profile

Carrier profile

There is a spot here on the corner that's getting smushed.  It catches my fingernail on the edge.

There is another spot that is getting smushed.  It catches my fingernail as well.

Here you can see it on profile.

 

Also, for reference, a picture of all the parts mocked up.

[Widder, SASS #59054]

About 3 years ago, I put a long explanation on the Wire about that 'cut' area on the timing ramp and tried

to correct the 'myth' that so many associate with it.

 

Basically, that mark is created by the edge of the snail cam (lever) and shows where that sharp edge of the snail cam

stops as it rotates up the carrier ramp.

Many people associate that cut with the Marlin Jam but in reality of timing, the Marlin Jam is created when the 

lower section of the ramp is lower than necessary for short ammo.

 

Opposite of that is when the lower section of the ramp is too high, it will prevent ammo from clearing the portal

before the carrier pinches it and causes the type jam you are experiencing.

 

In essence, Longer Ammo requires slightly slower timing.

Shorter Ammo requires slightly faster timing.

 

In one of your pictures, is that a 'scuff' mark in the lower section of your timing ramp, right below the 'cut' area?

 

..........Widder

 

 

 

 

 

 

[snozzberries]

Yes, there is a clear rubbing and scuff mark below the cut spot.

[Widder, SASS #59054]

Without handling and looking at the carrier in person, I think this is the area of your problem and 

that 'scuff' mark is what I was talking about in an earlier post.

 

This scuff mark is basically created from the tight rubbing of the snail cam on the carrier ramp because the ammo

stops the lever from smoothly rotating up the timing ramp.

 

Polish out that scuff mark a few .000's and your problem should be solved..... atleast with your 1.595 OAL ammo.

 

Remember:  if you polish out this scuff mark and decide later to use shorter OAL ammo, you could be in jeopardy

of having the real 'Marlin Jam'.

 

Good luck.    And thanks for posting the pictures.

 

EDIT: hey Snozz, it looks like a small divit in the ramp about 1/4" below the cut.   That is probably the

critical area of concern.   AND,  the shiny area running up the side of the ramp that starts at the lower

area of the timing ramp.   Just don't over polish.

 

..........Widder

 

[snozzberries]

Just for clarification, it sounds like the lever, with it's the red spot, interacting with the carrier, and it's purple outlined ramp, are what create the timing. Specifically, the angle of the purple ramp.  So by polishing it, I'm adjusting the angle. 

 

[Widder, SASS #59054]

Snozz,

Your pics are great.    YES, that interacting parts determine the timing.   And the scuff marks on the carrier ramp

is where your faster timing is creating your jam issue with your 1.595 OAL ammo.

 

Remember, try to test shorter ammo before you start polishing up those scuff marks.   I would suggest

something like 1.575 or so as a good testing measurement to start with.

 

Keep us informed.

 

..........Widder

 

[snozzberries]

 

4 minutes ago, Widder, SASS #59054 said:

Remember, try to test shorter ammo before you start polishing up those scuff marks.

 

Oops

 

The factory ammo at 1.555 does this as well, so I expect shorter ammo should be fine.  I'll try to just smooth it out without removing much material. 

[The Original Lumpy Gritz]

Outstanding pictures

Take a stone, a blend all the burrs you find.

Also remove all the sharp edges anywhere you can.

Polish that tunnel where the cartridge passes through the rec'r.

Smooth and blend the top part of the opening.

That's some rough machine work for sure.

You may need to remove. 005-.010 of metal from that wear area on the bottom of the carrier. 

Go slo....

OLG 

[snozzberries]

I don't have a stone, I've been using a tiny piece of 400grit wet sandpaper for the roughest stuff, and then moving to the Dremel with Flitz polish. 

 

Do you have recommendations on a stone? 

[The Original Lumpy Gritz]

Spray some WD-40 on the paper to keep it from clogging up.

Do you have the 1/2" rotary sanding drum that fits the Dremel? 

Carefully use that on the wear mark on the bottom of the carrier. 

OLG 

[snozzberries]

2 minutes ago, The Original Lumpy Gritz said:

1/2" rotary sanding drum

 

Yes, but that's like 20 grit sandpaper. 

 

After some light polishing, it's smoother and shiny, but I don't think I've removed much metal.  Probably 30 seconds with the dremmel on the slowest speed. 

 

You can see at the Red line, where the snail cam stops and makes its dent.

The purple line is the bottom of the ramp.

The green line really shows now the spot Widder was talking about.  "It looks like a small divit in the ramp about 1/4" below the cut.   That is probably the

critical area of concern."

 

I expect when it's getting stuck, that's where it's stuck at.  Several times when it's stuck I've wiggled it back and forth to try to unjam it.  How does removing material where it's already stuck help prevent it from getting stuck? 

 

[The Original Lumpy Gritz]

Take out 90% of that notch. 

Blend the surfaces  and and do a function test.

OLG 

[Widder, SASS #59054]

1 hour ago, snozzberries said:

 

 

 

I expect when it's getting stuck, that's where it's stuck at.  Several times when it's stuck I've wiggled it back and forth to try to unjam it.  How does removing material where it's already stuck help prevent it from getting stuck? 

 

 

WHEW..... I know the answer but typing it out might be difficult for me to explain....... but here goes.

 

When you start lowering the lever, the snail cam starts to rotate upwards on the carrier timing ramp.

Simultaneously, your cartridge will ride the flat edge of your lever back until your lever is vertical inside the

receiver.   Then the cartridge will fall onto the carrier.

 

While all of this is going on, the carrier continues to rise allowing the BODY of the cartridge to come thru the 

portal and the FRONT of the carrier wing area will then block the rim of your next cartridge.

When the timing is too fast for longer ammo, the carrier will start pinching on the 'case mouth/bullet area'

before it can clear the portal.   This upward pinch is caused by the snail cam interacting with the timing

ramp and pushing the carrier up a little quicker preventing your long ammo from clearing the portal.

 

Slightly lowering that 'critical area' will keep the carrier from rising too high, too fast.

 

Remember, all this timing issue is in conjunction with your OAL ammo.

 

All this being stated,  I'm just hoping we aren't chasing a rabbit.   But your picture did verify to me

what I thought was happening and in such situations,  your effort to slightly modify that carrier ramp

should solve your issue.

 

If you want to see just how effective proper timing can effect the Marlin 1894, check out this video I'm attaching.

Notice the OAL variations of the ammo I'm putting in the rifle (Widdermajik), including a couple empty cases.

 

..........Widder

 

 

 

 

[bgavin]

Dayum!
Impressive!
Thanks for the demo.

[Lou Graham, # 26112]

Widder - thank you for the explanations.  You gave me some advice you didn't mean to!  I'm going to play with ammo length and see what that does for me.

Snozzberries  - thank you for the pictures.  The mock up of how everything in the receiver goes together combined with the color-coded close ups is so helpful, I've saved all the pictures. 

[snozzberries]

I coated all the parts in BreakFree CLP, then dried them all off.  Reassembled the rifle.  Went to the range and shot 130 rounds without any jams.  Crossing my fingers it's fixed.  Thanks for all the help! 

[Widder, SASS #59054]

1 hour ago, snozzberries said:

I coated all the parts in BreakFree CLP, then dried them all off.  Reassembled the rifle.  Went to the range and shot 130 rounds without any jams.  Crossing my fingers it's fixed.  Thanks for all the help! 

 

Congratulations.

 

Just curious..... were you able to stay with your original and preferred OAL ammo?

 

..........Widder

 

[snozzberries]

I did not adjust the length of the ammo.  I left it at 1.595. 

[Warden Callaway]

Thanks snozzberries for keeping up updated on your progress and success.   So many times the original poster of a problem "leaves the building" without any comment. 

 

 

 

[Cheyenne Ranger, 48747L]

another atta-boy on your pictures.  well done

[The Original Lumpy Gritz]

2 hours ago, snozzberries said:

I did not adjust the length of the ammo.  I left it at 1.595. 

 

Now, go buy some Lotto tickets 

OLG 

[Widder, SASS #59054]

Because this thread was closely followed by a handful of Wire Pards, I want to take

this opportunity to share something about the 'myth' of the Marlin Jam.

 

For years, I've tried to explain to a few folks that the 'cut' area at the upper portion of the 

carrier timing ramp IS NOT the Marlin Jam.   Actually, it has very little, if anything, to do

with the Marlin Jam.   That cut only indicates where the snail cam stops as it rotates upwards

on the carrier ramp.

 

Think about it, if that cut was indicative of the Marlin Jam, then why did Snozzberries have the cut,

yet his problem was actually the opposite of the Marlin Jam.   

 

The Marlin Jam is caused by bad/slow timing in relationship to the OAL of the ammo.

The jam that Snozzberries was having was caused by a fast timing in relationship to his ammo OAL.

 

I Hope this helps many of you and I hope some of the mystique surrounding the 'cut in the ramp' can be

dispelled as causing the "Marlin Jam", as many Marlin shooters refer to feeding issues.

 

SNOZZ:  Thanks for posting all those great pics.   Ya dun gud!

 

..........Widder