Hello.

I've got a "drum" for an AR15 safety that I need to take some material off the flat side that interfaces with the trigger shoe.  There is a small tolerance stacking issue between the trigger shoe and the flat on the drum of the safety so that when the AR is switched to "Fire" the hammer won't drop.  I've got a small set of needle files that I've used for other small work but they just are not up to the challenge.  I've been filing and filing and I'm going to wear out long before that little piece of steel.

I'm no gunsmith so I'm not sure which file is right for the job, all that I know is that my little needle file set is obviously not the right thing to use and I don't know much about files.

The area I need to file is only about 1/2" by 1/4" or so.  Its small.

Any recommendations on a good file or even a file set to get would be really appreciated.  I don't have a budget to stay inside of as I usually prefer to get nice tools when I'm purchasing tools.  Every time I don't I get burned (like the needle file set described above ;) ).

Thanks!

Several times I have ground down the trigger were it sits just below the selector, I have never modified the selector/safety.

I have used sanding drums with Dremel and diamond knife sharpener plates.

You want an extra narrow pillar file.

Thanks for the replies so far.

What is the best way to do this - to remove material from the "fire" side of the safety drum or to remove material from the top of the trigger shoe?

With regards to the extra narrow pillar file, which "Cut" (#0, #6, #00, etc.) should I order for cutting the steel of that piece?

Just as some background to the issue.  I've got a Battle Arms Development BAD-ASS-ST safety.  It fits in my receiver just fine, and my receiver markings line up nicely with the 45 degree throw of the safety.  However, it seems that it doesn't quite work with my Geissele SSA-E trigger.  On fire, the back of the trigger (The shoe?) still hits the flat on the bottom of the center part of the safety.  I can pull that trigger hard and it just isn't close to releasing.

I thought maybe taking a little material off that "fire" flat of the center part of the safety might do the trick.  I hadn't thought of modifying the top of the trigger shoe until it was mentioned above but maybe that is a better way to go?  I was afraid that if I modify the trigger itself then it will have different dimensions regardless of whether it is on safe or fire.  But if I just modify the fire "flat" of the safety then it should only affect the "fire" setting of the rifle.

I don't want to use a different trigger and returning the safety to Battle Arms isn't an option so I'd like to try and make this safety work.

Consider a ceramic 'file' if you need a better surface finish.

They cut slower giving you more chances to correct the work.

#2 cut will give you a decent finish. #0 will cut way too fast.