Randy333 wrote:

On Sun, 7 Apr 2013 19:12:24 -0500, "RogerN" wrote:


I'm close to milling my AR lower receiver, this "95%" machined receiver
needs a pocket for the fire control group and 3 holes cross drilled for 2
pins and a selector/safety.

I found some instructions for machining the pocket using a DRO, they
recommend drilling the selector switch hole, machining the pocket then
drilling the trigger & hammer pin holes. Why not drill all 3 cross holes in
that 1 setup and then machining the pocket? I would think the drill bits
might be more likely to walk as they start through the 2nd side. I don't
see a benefit to set up for drilling, turn turn the part for milling, then
turn back to the first setup to drill 2 more holes, any idea why they would
do, or recommend this?

https://colfaxtactical.com/docs/Fire...%20a%20DRO.pdf

RogerN


Know where a complete drawing is? Would 6016-t6 bar be a suitable
peice to start with?

There are a bunch of AR prints on the 'net, just search around a bit.
7075-T6 is what you want.