Can it really be that simple? WOW I'm impressed - looking forward to trying it out! LAR mags will be my main test...
Yes, as long as the front part of your magwell has approximately the same dimensions as mine. Since they're all built in the same factory, I'd assume they're all the same unless they made some modifications over the years.
How critical is the placement and depth of the notch that needs to be filed? I was wondering if a deeper notch provided more "meat" (and therefore a more solid lockup) for the AR mag to latch in.
Placement is more important than depth. If the cut is too high, then the mag will sit too low and won't feed properly.
Depth should be 1.5-2mm. Any deeper and you cut through the spine of the mag, and if you go much deeper than that it may interfere with follower movement.
There will be instructions provided.
Got mine in the mail today - what a fantastic little device!
I tried 5 of my mags that I previously 'slotted' for the old mag adapter that used to be commonly available - and they all fit, released, and fed dummy rounds perfectly. The 3D printed 'guide' that you included was fantastic idea as well... the old adapter just had a measurement, which could potentially vary from mag to mag. The dimensions from your guide piece exactly matched my mags perfectly, so looks like it's the same!
This is a simple and inexpensive solution... and so far it just WORKS. I'm shocked and pleasantly surprised! I will give it a live-fire test soon and post some results.
Anyone try the Alberta Rifle AT15 mags yet with this adapter yet?
I'm wondering if the 'spine' on the ATRS mags have enough material for the notch that needs to be cut. The Pmag spine seems slightly thicker so this is not an issue.