I just had a 14.5" AR upper built in .22 TCM and purchased a couple hundred cases from Sleeping Giant Brass as well as 1K Armscor 40gr projectiles. I heard the Armscor cases are soft and don't hold up too well, so I bought the Sleeping Giant cases because they are formed from once fired LC 5.56 NATO brass.
I will only be shooting .22 TCM out of my rifle for now, so I'm very keen to hear of experiences with the BLK powder!
I'll start a new thread about my AR.
In the meantime, I'd love to hear he testing results on CFE BLK. It sounds promising for use in TCM rifles! I'll want to have a few rounds loaded before my upper arrives.