[jjk308 In Memoriam RIP]

The "rails' are probably the shell stops. They go on pins and are lightly staked in place, not riveted.

The bolt is supposed to come apart in 2, easily. The top is the bolt, the inside part the locking block. Your first gun was first year of production but I believe it should be the same. Maybe its just gummed up. Slide wear is normal. The older shotgun may not have been used much. For lube and corrosion protection I just wipe everything with a rag with some RIG or Penn Reel Grease worked into it. Oils tend to be pretty messy and you'll have rust problems if its used in rain or high humidity.

This shotgun is so reliable there's little repair info out there, and the only generic problem is feed jamming.

 

[jjk308 In Memoriam RIP]

Remington's diagrams don't even show a separate part but its price list has a "locking block retainer pin" for $4.12". An old NRA Firearms Assembly 3 book shows a "locking block stud", a pin stuck in at about the right location. Like kp321 says it doesn't seem to do much but at $4.21 unless shipping is too high you might as well replace it. If it fits. It really doesn't seem to do anything important and if the gun shoots well I'd ignore that and the slide wear.

The slide is part F401023 at $22.66. Usually the ends of the action bars wear first, making the start of a stroke looser, eventually preventing proper ejection and loading. On older guns bar replacement is supposed to include the slide replacement at the same time: F102324 V-28 870 FORE END TUBE ASSEM N/S 12 GA (FOR PRE-1984 GUNS INCLUDE SLIDE F401023) $37.08

 

[jjk308 In Memoriam RIP]

How would you even reinstall the pin? I'd have to drill the old one out and set the new pin, which I am guessing is installed with the locking block heated to a bright red/yellow, Probably be easier to replace the bolt with a gently used one.

Thanks!

grey

DO NOT HEAT THE LOCKING BLOCK! If it cracks you'll get a face full of shotgun shell and bolt!