As far as a 22 Center fire at or above 5000fps. When Nosler was developing the Ballistic Tip bullets, at that time a customer had their custom shop build them a necked down 284 Winchester to 22 caliber. They loaded up around 10 cartridges and did some test firing. The good news: the 50 grain 22's flew at just over 5000 fps and the bullets and rifle held together. The Bad news: the barrel erosion was so bad they couldn't deliver the rifle! A 22 x 378Wea. is just unfathomable!

I have a 6mm x 284 and shoot 70 grain bullets around 4100 fps. It is truly LOUD!!!

Ivan

PS. At 61 years old, I'm at the tail end of Original Steppenwolf fanhood. My older brother was a fan and got me hooked with "Steppenwolf Live", but then I've always been a little twisted!