Fixing the dreaded “Marlin Jam”
By Rusty Marlin

How the Action Normally Works:
As the lever is cycled, it slightly lifts the cartridge carrier which allows one shell to come onto the carrier. And the carrier blocks the other shells so they stay in the magazine tube.

The Problem

The "Marlin Jam" as it is affectionately known is caused by an inherent design/manufacturing flaw of the Marlin lever. The lever has a snail shaped cam surface that goes around the pivot screw. Every time the lever is cycled the carrier bounces on the forward edge of the cam. The forward most edge of this cam is left sharp at the factory (the flaw).

After many thousands of cycles, the sharp edge cuts into the carrier enought so that the timing is slightly changed. At first, you will feel a slight "hitch" when cycling, then the timing will get worse; the carrier nose gets lower in relation to the magazine tube opening so that two shells are allowed to exit the magazine. The first shell comes in on top of the carrier as normal, and the second shell slips past the carrier nose and gets trapped between the top of the carrier and the magazine opening in the frame.

Marlin calls this "letting in two" because rather than letting in one cartridge at a time, the carrier allows two to slip by.

Lever Edge after Stoning
See the cam After the sharp edge was removed.

The bouncing forges a notch into the bottom of the carriers' slide surface and over time (high number of cycles) lowers the carriers' initial pick-up height allowing the rim of the next incoming shell to slip over the front and jam it up tight. Note the notch labeled A in the photo.

Line indicates ccarrier wear

Simply changing the carrier out as many repair places do is only a temporary fix at best. The new carrier will get a notch forged into it from the sharp edge of the lever cam and over time will settle downward in the action and again give you the “Marlin Jam”. Following the steps below will cure this problem FOREVER.

The Cure for New Guns

For Coyote Caps Alternate solution

With new guns (less than 50 cycles) you can generally get away with just putting a radius on the forward edge of the lever cam. While this will lower the initial pick-up height slightly, it typically will still be high enough to prevent the dreaded "Marlin Jam" from ever occurring. If your rifle jams you will need to follow the steps outlined above.

Many of you will have guns that jam once and a while but haven't figured out why. You probably have an odd piece of brass or two in your collection. For example the gun might run fine on Starline or Winchester but lock up tight on R-P. R-Ps are slightly smaller than others and this will cause the problem to be sporadic. Eventually the gun will jam on anything you feed it and you will need this fix.

The Fix for Used Guns

Note: This is a good solution to general timing problems

Three things are required to fix the problem. The first two prevent it from ever occurring again and the third retimes the carrier to proper height. Don’t even bother to do them if you aren’t going to do item 2A or item 3.

Rusty Marlin, SASS #33284

Coyote Cap's Cure

Why Marlin has not cured this problem, long ago, amazes me.


But I don't have a welder!!!??

Some folks have used other pieces of metal. They normally grind down the carrier to fit in another piece of hard metal. Some used JB Weld or a similar adhesive to attached hacksaw blades, others used two jig saw blades (with the teeth filed off).

Here's what Butcher John Remington did:
I went one better. I cut 2 strips of jig saw blade. (very hard steel) 1/2 " by about 1/8 " wide and removed the teeth. JB Welded them onto the bottom bottom plate where the carrier hit to keep the carrier up a little. Probably 6,000 rounds through it now and there is barely a mark on the pieces or steel and the problem never happened again.

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Updated on 4/11/2007  By Our Excellent Staff