it's called the .223 short V1 it's not a sammi cartridge by any means. developed by a few guys on grey beard outdoors. I literally just machined the barrel this afternoon so havent gotten around to screwing it on yet.

the other end users were getting 2900-3k ft/sec with the 30-40gr class of bullets from a 22" barrel

I would like to try the 34gr varmint nightmare in the ar and possibly the savage but my main appeal for the savage was cast bullets over a few grains of titegroup for a cheap quiet load for my kids to shoot to their hearts content. I had to slow them down on the 22's due to the shortage and I just can't bring myself to replenish the stock for 10 cents a round. I can load a brick of these with cast bullets for 3-4 cents a round and some time.