Inf I recall sorrectly, in general the Modified choke is about .020" less than the shotgun's bore. So called turkey chokes are essentially extrafull chokes ... about .040" restriction. It is typical for the turkey choke to extend well past the muzzle. Some more than others. Many are ported to assist in mitigating the recoil of heavy shot shell loads. A 3 1/2" 12 ga. max load kicks like a mule.

Extending beyond the muzzle is nothing to be concerened about.