I have been given an assortment of carbons. All the nocks are too small for the B50 string on my Hill bow. What nocks are out there that have a wider throat for thicker strings.

I use nock adaptors and 5/16 mercury nocks

The Accunocks are wider than a standard nock.

i've gone to all Easton "S" nocks.

Like trapperDave said get some nock adapters and use glue-on nocks like Bohning CLassic's.But for push-in nocks I like 3D Easton super nocks,they have the largest and deepest throat of the push-in type nocks I have found.How many strands and serving size are you using,you could try a smaller diameter serving also.