Kevin,

The 455's generally are good shooters from the factory. The Yo Dave trigger kit works well. The inletting of the 455 stock is a somewhat loose fit to the action. I think the 455's definitely benefit from pillar & glass bedding. After pillar bedding mine, I could lay the action in the stock and still had about 1/16" of play forwards and backwards as well as side to side. So glass bedding was also needed. My CZ had a weak firing pin strike so I upgraded to a JP Chrome Silicon Increased Power Striker Spring which solved that issue. I haven't seen any metal mags for the 455 but the DIP aluminum mag well with extended mag release is a nice upgrade a well. There are many nice aftermarket upgrades for the CZ 455 (https://www.diproductsinc.com is one good source).

Lilja also makes match grade drop-in barrels for the 455 but I've been happy with the improved accuracy of my 455 with factory barrels after pillar/glass bedding and changing the firing pin spring.

"Good judgment comes from experience but unfortunately, experience is often derived from a series of bad judgments"