No nobody else is trying to get in because it is a market that only exists as a figment of Knight Marketing's imagination. I thought they learned the first time they tried this but apparently not.

It's the old razor/razorblade marketing ploy. Sell you something you'll be forced to keep buying accessories for (that only Knight supplies), keeps the revenue coming in as long as you want to keep shooting it.

We have .50s and .54s, both with loads of components by numerous manufacturers. Why would anyone want to buy a .52 in between where components are limited, and what possible advantage over either of the other two calibers could they pretend exists?