I used to be all about the diffrent oddballs.
.30 herrett in an AR15
A 7.62x39 bench gun
A .303 Brit single shot
.45 win mag (not .458) bolt action carbine
All the European military rifle cartridges and a couple from the far east
But I eventually tired of the hard to get or make brass, no reloading data, and for what???? A round that goes BANG! and puts a bullet hole in a target just like 308/30-06/223 will.
Now all my rifle chamberings are as vanilla as they come 223, 308, 30/06, 30/30 and 357