TM USP (Full Size) O-Ring Replacement
 

Hey folks,

I bought a Tokyo Marui USP a while ago, and sadly the o-rings in the magazines seem to have gone (the mags leak gas visibly around the edges of the bottom).

I grabbed a set of replacements from Eagle6. They're a bit thicker than the stock ones (by design). I'm having a lot of difficulty installing them - I can replace the o-ring itself just fine, but putting the base back in the magazine is proving impossible. I just can't seem to get the pinholes at the bottom to line up right.

Has anyone done this or have any tips?

Buy the o-ring kits from princess auto or crappy tire and save the hassle.

Most magazines use the same orings made by the same. I grabbed a kit and compared it with one of my pistol specific magazine orings like you did and I realized they're the same thing.

If it's too thick you can sand it down little by little.

800 grit sandpaper + a wooden stick or something larger in diameter than your o-ring and put it on a drill chuck and sand it down to desired thickness.

If you mess up just buy an o-ring kit and save money. Cad to GBP is horrible and last time I checked out with them they charged $30 for shipping on a small part.

This shit was a pain in the fucking ass for me, needed vice grips to clamp down the base plate so I could hammer the pin down into the magazine.

I also used a piece of tile to use as a "strike plate" for my rubber mallet so it can transmit the force a little more appropriately.