Hello all, first post, longtime looker. My wife's 20 gauge Win. 101 is not firing the bottom barrel. The firing pin is barely denting the primer, but not enough to cause ignition. I assume this is a weak firing pin spring? Anybody seen this before? Is a 101 a bugger to do the replacement on? Any other common things/springs to replace when its in for work?

Thanks for any help!
Forrest