Re: stevens model 200 300wm, small or large shank?
I'm at work and can't see what SFY posted, so I'll take the chance of giving the same answer twice.
It is a small shank.
Stevens 200's do not come in any form of large shank.
Even if it was a Savage it would very very very likely be small shank.
Large shanks are only on RUM's(that they don't make anymore), WSM's, and target actions. None of which are made by Stevens.