I have a few OEM buffers for a Marlin Camp 9, but they are too brittle with age to use. I recently bought new urethane buffers and noticed that they are molded items.

Has anyone experimented with DYI silicone molds to make their own buffers? I have three unused OEM parts that should make a good casting mold, but don’t know which liquid material would be correct or optimum for the final product. Also which company’s product would best to go with.

Could one be 3D printed? Probably could make one on a mill maybe

I don't know of any material you could use at home.
I think parts like this are cast from a melted plastic that requires special equipment.

I'm not familiar with the marlin buffers, but one man I know makes his own buffers for a number of firearms using orange road department traffic cones.

These are made from a super tough polymer material.  He just cuts out the type he needs and gets trashed cones from most any road crew or by "appropriating" one off a deserted street.

What about that resin they pour on bars and once it sets its tough as hell, you could press the OEM buffer into clay and let it harden then pour that into your mold

If you have an existing/good dimensions buffer still then take a mold of it. 100% silicone caulk (color doesn't matter) mixed with a small amount of cornstarch at a time until it's a putty. That putty is your molding compound.

Have a glue gun and some of the hi-temp glue sticks? Or maybe just some of the glue sticks? Melt that into the mold you made from an existing buffer and let it harden. Trim the flashing as needed.

I'm not pulling your leg - honest to God it works to make buffers that last a surprisingly long time.

ETA: I should add that most modern buffers are made from polyurethane or polyethylene rubber. Guess what many hi-temp hot melt glue sticks are? Polyethylene rubber.

As an alternative once you have the mold - dust it thoroughly with chalk or talc and put silicone caulk directly into the mold. Once it cures you can use that as your buffer. I tend to prefer the stiffer rubbers such as you can get from hi-temp hot melt but there are a lot of options you may have kicking around your shop already.

I give this a try. Got all the materials mentioned already, and five OEM buffers to use for making the molds. Thanks

We had a lot of R&D that went into the LARB buffer cap. You can mold them, we lathe turn ours.