I was going to ask about bit and set-up. The picture is.. umm.. 'not pretty'.
Drilling a partial hole can be a nightmare if you don't have the right bit. I guess you know that now, though. :)
Use a bit with a flat end, no point. And also a template with a guide hole as well as a drill press, it will help prevent deflection.
Then drill very slow.
Alright well here is where I fucked up. The drill press I got doesn't like to keep the depth very well. It travels after so long because of the immensely harsh vibration.
I was going way to fast honestly because I wanted to just be done. That is my fault and well just gonna happen. The main thing here is TAKE YOUR TIME!!!!! I wasn't having a bit of that shit near the end.
8mm end mill bit with a longer cutter surface is key. You will need a shop vac to clear the cuttings because they will seriously bind the cutter. Found that "speed of death" works best when milling.
DO NOT USE OIL WHEN MILLING!!!!!
When you are drilling yes use the shit out of it.
On mine I drilled out the entire area above the trigger guard. Just because my drill isn't spinning fast enough to cut clean and it would tear right through that shit like foil. So I just drilled it all out, with a drop in trigger it doesn't matter anyways. The casing will cover the hole.
My safety selector switch had wayyyyyy to much pain or whatever in the groove so I filed it down and worked like a charm.
The original ar trigger to me just had way to much slop so I got a 2lb trigger. Yeah it is touchy, but it is what I like.
I wasn't having a bit of that shit near the end.
lol.. I've been there.
Ok first thing I learned is that you must have a solid level stand to mount your drill press.
Second thing is measure 9 times cut once.
Get an 8mm end mill bit, set of files, and a dremmel.