[plumbermario]

What slugs can be shot through an improved cylinder choke on an 870 express?

 

[robocop10mm]

Any shotgun slug can be safely shot through an improved cylinder choke. you will not get any kind of decent accuracy unless the barrel or choke tube is rifled. Our new 870's have factory improved cylinder barrels. People are finding a bit of choke to be a good thing (liability for fliers). Slugs run through them with out any problems.

Never try to shoot a slug out of anything tighter than modified choke.