QD AR15 Lower Milling???

[Yugo]

So Im ready to finally do my lowers that I got from aimsmall a while back and I got his jigs as well.

I have a drill press and a X Y vise from HF.

What size drills do I need and what type of drills do I need to get this job finished?

[ar15barrels]

The trigger/hammer pin holes are 5/32" and the selector is 3/8".
Drilling undersized by 1/64" and then using a reamer to get the final size is the better way to go.

[toddh]

So Im ready to finally do my lowers that I got from aimsmall a while back and I got his jigs as well.

I have a drill press and a X Y vise from HF.

What size drills do I need and what type of drills do I need to get this job finished?

Hundreds of youtube videos with descriptions of tooling used.
Lot's of build threads with descriptions of tooling used.
Dozens of websites that sell tooling along with their jigs.
Even the blueprint (you have a copy of a print.... right?) shows the hole diameter.

.

[Yugo]

The trigger/hammer pin holes are 5/32" and the selector is 3/8".
Drilling undersized by 1/64" and then using a reamer to get the final size is the better way to go.

Thanks. I ordered a whole set. So it should have these sizes. I will do the reamer way, thanks.

[Flintlock Tom]

You will need end mills to do the fire control group pocket.

[762x39]

Drilling undersized by 1/64" and then using a reamer to get the final size is the better way to go.

If you use an undersized drill how do you center it in the jig?

I have found that this is the best tool for the job.

https://www.mscdirect.com/product/details/02535102?item=02535102&fromRR=Y

[ar15barrels]

If you use an undersized drill how do you center it in the jig?

You start by using the standard sized drill bit that the jig wants and you just peck the surface to create a detent which is located according to the jig.
Then, swap out to the smaller drill bit which will center itself in the detent.

[762x39]

Well, I suppose that is easier than using a transfer punch, still requires doing it twice though. Drill/ream combo, does it in one shot.

[ar15barrels]

Well, I suppose that is easier than using a transfer punch, still requires doing it twice though. Drill/ream combo, does it in one shot.

Drill/reamer combo is more expensive, not as precise and may have trouble fitting through the drill bushings of a jig.

[Yugo]

Ok so im at the final stage, making the trigger hole. I ran into a problem the 5/16 end mill that the instructions ask for does not fit into the hole of the jig and is way too short to even reach the bottom of the pocket.

I take it that I will need a 5/16 x 3" bit to be able to do this.?

[Yugo]

never mind about my last post, I used the jig and a 5/16 drill to make 2 holes one on each end and the took the jig plate off and free handed the rest of the mill with an end mill to make the perfect cut.