Gun shops, gun shows, want ads
You can find parts for many westernfield shotguns at Numrich gun parts. WWW.e-gunparts.com
You can purchase parts for a Ranger model 30 16 gauge shotgun at these locations. Gunbroker, Topgunsupply, Budsgunshop, Gunpartshop and Midwayusa.
the thing hold the barrel to the pump
This is the same gun as a Mossberg 500. You can try a google search or go to the gun parts Co. online for a diagram of an exploded view. Mossberg should have one as well.
I would start my search at Numrich gun parts corp.They may be found on the web.
There are some sources for Crescent shotgun parts, but it is very possible that parts will have to be repaired/made.
DO NOT ATTEMPT TO USE PARTS THAT WERE NOT MADE FOR YOUR WEAPON!!!!!!!!!!! Danger, danger, danger.
I always start any of my searches for gun parts at Numrich Gun Parts Corp.
I have parts for that model. firstname.lastname@example.org