Need Help Beveling Polymer

[Sheperd80]

I decided that i want to do a little more beveling inside my magwell (m&p9). Ive filed and sanded on it a bit with 400 grit but before i go further i need some advice.

400 grit has it feeling a little rough still. Would finer paper get it nice and smooth? Or maybe wet sanding it to a higher grit paper? Or maybe alcohol?

Thanks for any advice.

[Wolfie_AR]

Not sure about polymer but with most things, you'd use finer grit to get the surface smoother.

Keeping an eye on this thread as I'd be interested in doing something like this myself.

[Sheperd80]

Yeah it seems like no matter how fine you go it still leaves the surface scratchy. Ive heard of people using plastic polishing compounds to get it back to smooth but im a little reluctant to do that to a gun havimg never used the stuff myself.

[Sheperd80]

Ok i just went ahead and tried it and am pretty happy so far. I went pretty minimal so as not to screw anything up or change it drastically. The dimensions are still well within uspsa production limits for magwells.

*Edit* according to 2010 rulebook you can only change the "longitudinal" dimension of the magwell. Meaning front to back. Increasing the width is not production legal as far as i can tell.

Heres what i did:

I used a small flat metal rasp and filed flat on the existing factory bevel to make it slightly larger all the way around.

Then i angled the rasp 3 different ways on each edge to get it somewhat round, and i used a rat tail file in the rounded corners of the magwell.

Then i carefully cleaned up the gnarls amd burrs left by the rasp with a razor knife. There are some raised guide lines inside the magwell that get a little messed up where you file. The knife fixed that as well.

Then i just step sanded it with regular wet dry sandpaper all the way around to a nice smooth round finish starting with 220 then 320 then 400. Then hit it again with wet 400. This part took a little elbow grease but eventually it got nice and smooth.

The sandpaper left the polymer with a matte look to it but it actually feels pretty good. I may come back with some plastic polish later but i think it will work as is.

I did some practice reloads and it feels good. The difference is slight but i could tell when i started to seat a few mags a little crooked they slid right into place. Im tempted to go further but for now i think its good enough.

Ill post pics later, battery is too low to flash.

[OliveDrab]

Try 600 then 800 and up into the 1000s. Then try a rubbing compound with a Dremel.

A member just posted an undercut trigger gaurd on his glock that looked factory due to his methods.

Goodluck,
-OD

[Sheperd80]

Try 600 then 800 and up into the 1000s. Then try a rubbing compound with a Dremel.

A member just posted an undercut trigger gaurd on his glock that looked factory due to his methods.

Goodluck,
-OD

Thanks ill try that

[kmca]

If you have a Harbor Freight close by, the blue buffing compound works very well for plastics. Just run your rotary tool at a slow speed so it doesn't burn the plastic.

[Sheperd80]

If you have a Harbor Freight close by, the blue buffing compound works very well for plastics. Just run your rotary tool at a slow speed so it doesn't burn the plastic.

My girlfriend and i made a very strategic move recently. I now live within walking distance of my shooting range, another lgs, harbor freight, home depot, and weinershnitzel. Score!