I have friends that hunt prairie grouse. It isnt really a short barrel game. 26 barrels is about my lower limit on roosters that are in the same neighborhood.
Ive never had a shot on a sharptail that was less than about 35 yards. They sure are spooky.
Screw in chokes are a bit overrated. Considering the gun, if it was 26 to begin with (if, in fact it was a 28 barrel to begin with, a pox on the house of whoever cut it to 24) had IC and MOD chokes to begin with, you could have played with your loads to get looser or tighter patterns.
Most guys, maybe not most guys here, but, most guys, never learn how to shoot and load for a single choke.
Best,
Ted