My 26 and 23 inch 870.Supermagnums did decent w a variety of shells. All 3 inch. Superfull Remchoke.
Did OK w other xtra full and ported tubes from.MAD, HS and others ( coworker had a bunch ).
Seriously, the fairly cheap Superfull was the winner.
Winchester HV 4s was also the better load, but even those old duplex Remingtons did OK. All usable to 30 yards
Think the lead 4s got good killing to 40 yds energy wise.
Big Green had some bbls with less than properly machined choke tube areas, and impact could be off point of aim. My buddy got two 1187s new so afflicted. They were pathetic.
New or used, from seeing a few bad ones way back, i check everything. My 870.supermagnums ( had 3 of em ) have been perfect.
Farthest tom was killed at 42 yards.
Did pattern same gun ive run last 10.yrs w Magnum Blend and its fine.
Only problem there is wallet damage. LOL