Marlin 336 Gouging Cartridges on Load

[Airgead]

Hello all - I just purchased a new-to-me Marlin 336 in .30-30. The serial number puts it as a 1979 manufacture.

After I did a thorough detail cleaning on it, I cycled a round all the way through from load port to ejection to check the action. After ejection, I noticed that the brass casing had some significant length-wise gouges running down the case. I'm concerned that these are deep enough to weaken the case walls, especially over multiple loads.

After some brief experimentation and close inspection of the loading port, it appears that the lip of the load port on the receiver isn't smooth and is gouging the brass in at least two places. In one place, there's a significant notch (in the pic of the receiver, it's the right yellow square). In the other place, I can't tell what's causing it. Pushing the cartridge in slowly, I can actually cause a ribbon of brass to peel away.

Any thoughts on how to fix this? Can I hit it with some sort of dremel head to smooth it out? I hate to take tools to the receiver willy-nilly. Or is this a gunsmith-class repair?

 

[rcmodel]

Yes, it needs to be polished smooth.

Use a Dremel if you feel competent to do it without letting it get away from you.

Or a round stone, or strip of black emery paper on a dowel rod might be safer.

It would best be done with the rifle apart and the loading gate removed.

rc

 

[Airgead]

I'll try the rod w/ emery paper. I wasn't keen on the Dremel because I don't want to take off too much metal. Thanks!

 

[herrwalther]

Trying not to hijack the thread. Same thing happens on my Marlin but I do not have a burr on my load gate. The scratches on mine appear all the way around the case so perhaps a tight chamber? The scratches on mine do not appear as deep and look more like smudges,.

 

[rcmodel]

That doesn't sound like anything to worry about.

The case expands against the chamber wall when fired and my come out with dull shiny spots or rings where they gripped the chamber.

But post a good close-up picture of a case for more then a WAG though.
My Crystal ball is in the shop for a buff & wax job.

rc

 

[4v50 Gary]

I wouldn't use a dremel. I'd get a polishing rod and polish out the burr.

 

[herrwalther]

The case expands against the chamber wall when fired and my come out with dull shiny spots or rings where they gripped the chamber.

That would be my thought if the cases were fired. Hopefully the pictures can show it as well as I can see it.

 

[rcmodel]

Well, its doing it during feeding then.

Carefully inspect inside the gun for brass rub-off.

Probably a rough edge on the chamber mouth, or?

At any rate, if its taking brass off the unfired case?
It is leaving clues and brass tracks behind where it is doing it.

rc

 

[Airgead]

Well, I got the emery cloth and smoothed the load port but in disassembling it that far (which I hadn't done originally) I found tons of gunk and crud in the parts I removed. So I need to do another round of detailed cleaning because the stuff is definitely affecting the lifter's operation. Not sure I'll finish that before the weekend. :banghead:

 

[Airgead]

I spent about two hours on this tonight, polishing away with the emery cloth. I have it now down to a single scrape down the case, but not nearly as deep as it was. My fingers are worn out now.

Is it common for Marlins to leave some mark down the case when load them - i.e. am I chasing a perfection that isn't there? I can't feel any burr with my finger now so I'm wondering if I need to hit it VERY lightly with something powered.

I was using a progression of coarse -> med -> fine emery cloth around a 5/17 dowel.

 

[rcmodel]

Use a cotton Q-Tip and rub it all over the surface.

If there are any microscopic burs remaining, they will snag up cotton fibers and you can figure out where they are.

rc

 

[Airgead]

Well, I've spent another hour on the ramp going from coarse to fine. I'm still getting streaks down the case. Not nearly what was going on before, but it's pretty much the same as where I was at yesterday. I tried running qtip all over the ramp and nothing sticks. I even shredded it so it would be very whispy and still nothing.

Is it usual for there to be some marks on the cases where you load them? This is my first lever gun (owned) and I've never really looked closely at the cases before. Maybe I'll toss the cases in the tumbler and see if they marks polish out. As I said, it's definitely not the gouge it was before so maybe this is normal?

 

[rcmodel]

Tell you the truth, I never paid any attention to my Winchesters.
Or my .44 Mag Marlin.

But my guess is there will be some scuffing visible on polished cases.

There is a lot of pressure on the case while it is going though the loading gate, and changing directions while holding down the loading gate.

IMO: If it isn't leaving deep gouges that could lead to case failures, it isn't worth worrying about very much.

rc

 

[Airgead]

Yeah, it's definitely not leaving the gouge I was seeing before. It's just case marking at this point. I was suspecting that it's normal because the force between the load door and the receiver would pretty much assure some sort of marking.

Thanks for your advice on this rcmodel.

It was a good experience. I've ended up tearing down the whole rifle to get the magazine tube off. So I'm going to refinish the pretty beat up stock and forestock now. I have them sitting in Citrustrip now. Going to do a Linseed Oil + Poly semi-gloss finish.

 

[herrwalther]

Went over my Marlin with a fine tooth comb again. Didn't see or feel any noticeable burrs. The marks on my brass are not gouges and I didn't find any brass shavings inside the action. In confirmed this by having my wife hand rounds to me with my eyes clothed to see if I could feel the marks. Less of a worry at this point and merely cosmetic.