older 12 ga. won't stay locked up when it is pumped. took it to a waannabe smith a year ago.ok, to be fair he was just getting started to be open to the public. said whatever part keeps it latched is no longer produced by remington or available. wouldn't consider maufacturing a part. is this a common problem? the fix?

Action bar lock or spring, or both. Seems there are plenty available on E-Bay. The 870 is back in production, but I haven't seen any new parts yet.

Also check the fore end tube nut that holds the forearm on. If it is loose, the fore end tube may not go forward far enough to bring the bolt into battery. It can be a problem with pump shotguns of any brand.

thanks guys