I recently bought my grandson a Rem pump shotgun that came with a screw in choke that says "Rem Choke" on it. How will it relate to the common imp cyl, mod, or full chokes?

No difference, that is just what remington calls thier chokes I believe. It probably says what size it is on it as well. I don't think rem choke is a size, but rather the brand name. If you only got one choke with the gun my guess would be it is a modified choke. I think that is the standard with the 870's. Mossberg 500's come with all three chokes.

You can buy any after market choke that will fit a remington and use it as well.

Paul

Rem Choke is just the brand name Remington calls its chokes. My 870 only came with the modified choke in it. I bought a full choke for $17. I think the most expensive choke is turkey, and it was $21.