Coonan .357 Mag. Automatic Compensated Pistol.
I think the Coonan qualifies as a strange gun for the choice of caliber - generally speaking it’s considered to be too much of a PITA to produce a detachable box magazine fed semi-automatic firearm that reliably loads and cycles large caliber rimmed rounds, the gas powered Desert Eagle standing as the usual exception. I personally prefer the aesthetics of the Coonan to the Eagle. The Coonan also uses a more conventional linkless Browning tipping barrel action.