I had an initial issue with the adapter. Because it fits the GI magazine so tightly, I didn't realize that the magazine catch wasn't seating in the magazine slot. So I ended up grinding the lugs some more and the front of the magazine lips sits on the lugs and it feeds and ejects properly for about 6 rounds. What I'm discovering, is that the magazine doesn't sit quite vertical in the magazine well. If I hold the magazine back and cycle the rounds, I can cycle a whole magazine reliably; if I don't, I get 5 or 6 rounds and then have to re-seat the magazine. Now I have a couple questions for you:
1. Since the front of the feed lips are obviously high enough to feed the rounds, have I ground it enough?
2. Is the magazine supposed to sit level (seems like it should) and if it doesn't do I need to look for another problem?
3. There is only a sliver of metal between the magazine release tab (the tab for the AR mag release) and the top of the adapter and it is bulged upward. Is this normal?
One at a time.
1. I have no way to tell how much is ground off, but better to check out the possible fixes below to start with.
2. No the mag is slightly lower in the rear so the bolt doesn't hit the primer in the middle. Standard protocol is to only touch the top 1/3 of the round to start it moving.
3. It sounds like your mag catch is too long and catching the follower, causing the rounds to misfeed. This also causes the bulge as the mag being forced into the adapter against the magcatch can't slide out the slot, so it bends the little keeper tab. Another possibility is the adapter is not firmly against the bottom of the receiver causing the rear of the mag to hang down too low. You will have to adjust these two things to fit your rifle as I didn't(/couldn't, as the magcatch wasn't complete) spend the time tuning it to a rifle, thus a kit.
I think you will find that the mag is not fitting as tight as you think in the adapter. I believe the adapter is slightly off center causing the mag to rub the narrow part of the magwell of your receiver. Some rifles have a slightly narrower front than others. It may be necessary to hit this part of your magwell with a file slightly. Look in the bottom of your magwell with the adapter on, but mag out. You shouldn't be able to see the edges of the receiver as the mag is almost as wide as the adapter. If you can see the narrow part of the receiver, you will need to hit the edges you see with a file. Maybe 3 licks per side or so until the mag isn't touching them.
Here are some measurements for the magcatch I start with. It should be about .038 from the edge of the catch to the outside of the 1/8" z bar you welded it to. This is a good starting point. Yours may need to be slightly shorter, but should not need to be longer as it can and will interfere with the mag follower. Grind it at a slight angle starting at the bottom as it will make for easier mag loading. The rear of the adapter should be firmly against the bottom of the receiver, and no taller than the blank adapter was when I shipped it (I believe it was 1.935, but I'll check tomorrow and be sure and tell you.) You can adjust the rear height-to-receiver tightness by bending the tab(of the adapter) that is held by the paddle magcatch of your rifle.
All these little hiccups you are experiencing, I experience on every one before I cure them and box them for sale. I usually go through 90 rounds in each adapter and a few hours of fine tuning. Imagine doing 200 at a time.
Appreciate the info and I'll troubleshoot, but this one is from the last batch of completed adapters you sold. Bought it in April, I believe.
Where I'm seeing wear on the mag well is on the rear and sides, but I'll check it out again.
Sorry, I get confused about who gets what. If it was one of the finished ones, it worked repeatedly before shipping, so I would still check for centering. If you remove the adapter and insert a mag in it is it still tight? It should be loose enough for the mag to fall out when the magcatch is pressed. If it isn't, send it back and I'll send you another. Make sure the magcatch spring is holding the magcatch closed and that the mag isn't just coming loose from the recoil. I have had a few springs, that for some reason, have not held tight enough after a few months.
I'm packing you one up now.
I'll try to ship this one off on Monday.