What’s causing the lever to pop open on my 336T ? I have to hold it closed when I shoot it . How hard is this to fix ?

sounds like the lever plunger spring may have been changed......or weak ?

Wolfe makes lightweight springs for Marlins.....

Makes opening/closing lever easier.......

but can & will not stay locked in place....

What a pain. I bet if you post this over on the Marlin Owners forum, you'll get an answer quickly.

I believe I answered his question.........^^^^^^^^^^

I can even send him an OEM plunger spring if he likes

simple to replace........

Thanks for the replies . Seems like an easy fix .

We posted at almost the same time, so your answer didn't show up for me until I hit the "Post Reply" button and apparently you had just posted it.

Its a race Marlin

Stretch or replace the plunger spring.

It is easy, I was gifted an old 336 in 35 Remington last year, I put a new finger lever plunger and spring in it, as well as a new two piece firing pin, that old rifle should be ready for a hundred more hunting seasons.

Replace the plunger and the spring while you have it apart.

Did this and it fixed the problem.

Someone may have bubba'd the plunger and spring , replace them both. It may then be too tight so then research that fix , it aint that hard to remedy.

I replaced both and the problem is solved.

The only one I ever had did that brand new and the sights were mounted a few degrees off on opposite sides of the barrel. Had to have a smith fix both issues. This was a rifle my dad gave.me for Christmas. JM brand new. I sold it after he died.

If my reloads get warm the lever will pop open.

To the first part of the thread, I replaced the finger lever plunger and spring not because the lever was popping open, but because it was too loud on fully closing gripping the rifle in preparation for a shot, that loud CLINK would have caused a deer in the thickets to bolt to the next county.

To the hot loads, I don't think so, I push the 220gr Speers to 2175 fps with Leverevolution powder in an old Matlin 336 35 Remington, that's a hellbender load in a lever action for sure, I use Hornady brass, the pockets are still good and tight, accuracy is stupid good for a lever rifle.

Gentlemen, I just went thru this about a year ago on a 336. This may not be the cause of anyone elses 336, but is was on mine. I converted a pistol grip rifle to a straight grip. I did use new factory parts. To make a long story short, it was popping open when fired because the bolt locking lug was not fully seating in the bolt and receiver lug recesses. To fix it, I had to grind down the contact pad on the top (as it sits in the rifle being held) of the lever that stops travel of the lever when the lever is closed. This fitting pushes the locking lug higher into the locking recess. It is easy to do. File .010" off of the pad and check the fit until you only have .005" to .010" clearance between the lever pad and the low tang. The lever popped open every time I fired it before doing this. After this fitting, it has never popped open when fired. RJ