Please note that I am not shilling for Northern Rifleman. I bought the upper here because of the low price. It may turn out that you really do get what you pay for but at this price I can afford this fun test. Most of the uppers I've seen were in $1100-1400 territory, a little steep for me. I attached it to my Stag Model 1 to find out about the round.

I have not been able to find all the components I need to make the BLK round but I ordered this one after I found four whole boxes of Remington UMC in a MO gun shop, their entire inventory. I only got 40 rounds through it on Sunday and the first few showed the chamber and feed ramp to be a little rough. After it cycled a few rounds it settled in pretty well and we got the scope sighted in. Using 2-8 grains less (handgun) powder than the .223 it really does feel like you are shooting .30 cal with about the same recoil as a .223/5.56mm (Hodgdon does not list a 5.56mm load that I see but that's mostly what I shoot in the 5.56-rated upper I have from Stag Arms). It seems pretty accurate out of the 16" barrel so far. Not spectacular, using a Nikon Buckmaster 4.5x14 scope, but pretty good. We'll see after it breaks in some more. Only time will tell.

Luckily I was able to find the missing loading components at the Springfield, MO gun show on Saturday, primers and Hodgdon H110 powder, so testing can move forward. It would be pretty cool if someone made a varmint model in this round but since it was developed for the M4 platform the longer barrel may not be advisable or I'd expect we would have seen one by now. Still, I can see a new lower with the fixed M16 stock in my future. I like what I see so far!