We have an adjustable gas block coming for it...they were supposed to be in from the machine shop last month, but aren't here yet. I don't have anyone in-house to check the delivery with (technically I'm not here either, as we're on a holiday shutdown) or I would give you a current ETA.
Machine shops can be a bit like the cable company. As long as there's a today, there's a next week. And some day next week becomes today, and the cycle repeats.
From you're description of running flawlessly without the can and having some issues when running the can, I would assume that it is can-related. It isn't surprising that you wouls have less issues with the gas running the same can on a 223.as the LAR-8's bore is significantly larger and your back pressure is significantly lower. I don't know if an adjustable block will help in that instance, but it the first thing I would try. A regular (223) gas block isn't going to provide the best results as the gas tube will have to be bent to go straight into the receiver (the gas block and the receiver are both taller than standard on the LAR-8).
Thanks.
Steve/RRA