I am not a gunsmith nor do I even tinker with my guns. I had my .458 lott cz bedded per the instructions of cz. I let my gunsmith talk me out of having it crossbolted at the time. He clamed that they did not help prevent splitting. I am now wondering if this was a mistake. Are they really needed? Can they be added now once it is already bedded?

I think it is possible to add the cross-bolts after bedding...and I would.

I have CZ 550's in 375, 416Rigby, and 458 Lott all are bed and cross-bolted...

I definately would add the cross-bolts. Your gunsmith probably didn't feel comfortable/competant to do it properly and not make a mess of the stock (I sure don't). As a heavy caliber bolt rifle recoils, the lug and the tang press back, however minutely, in a properly bedded stock and the stock wants to bulge at the sides to make up for the rearward pressure. Stocks usually split through the trigger well and some through the magazine well. The crossbolts hold the stock together and re-inforce the recoil lug recess and the trigger well and prevent splitting. The rear tang of the receiver should be slightly releaved to keep the stock from chipping at that point. The relief should not be noticable.

Thanks for the answers. I guess I will start looking for another gunsmith to put those crossbolts in. He was told to relieve around the tang so that should already be done.

Try Roger Farrell over in Georgia. He has an add in this edition of Rifle magazine.