Worked on the Gen II TCM-AR Mag Adapters while up at the main shop and tested them yesterday with great success. I burned through all my TCM ammo while making adjustments to the new adapters.
New adapters take stock TCM mags and fit std AR magwells. They are very similar to the glock mag adapters that you see out there and I am sure you could modify one of those for the TCM mags (minus the bolt catch).
I'll get some pics up when I can and get order details together.
Here is our working pre-production 22 TCM-AR magazine adapter!
We've looked at a couple different mag catch systems and this is the easiest one to make right now. You can reach it with the trigger finger. Depending on you magwell, the stock TCM mag might be a tight fit. You can squeeze the mag a wee bit in a vise or open up the magwell a bit if yours is too tight.