Close, but no cigar. Your Montgomery Ward's shotgun Model 6OOERI is the Remington model SPT 58. You can get the firing pin from gunpartscorp.com for $12 plus hipping. It is part number 100170D.
dry fire, generally dry firing a Remington shotgun won't damage it, especially on occasion just to put away for storage.
The Remington 870 is a type of shotgun which is known as "pump action". The Remington 870 requires the individual to "pump" the shotgun following each pull of the trigger. It is considered to have a slow rate of fire due to the pump action which is required.
Try 'Gun Parts Corp', you can find them "on-line" at e-GunParts.com.
mossberg353
Ask a gunsmith for help
Yes.
The Remington Society of America has a services/parts link too but e-gunparts.com is a good place to start.
Try e-gunparts.com
Try e-gunparts.com
You need a gunsmith.
My first guess would be that it needs a real good cleaning, this is a gas operated and not a recoil action. They haven't made them in about 50 years there might be a bit of junk in there ;) Remember this is also Remington's first gas operated shotgun it and there have been a lot of improvements it won't be as forgiving as modern versions.
They have different parts numbers, so they are NOT likely to interchange. The good news- gunpartscorp.com shows both are in stock.