what can i expect out of a jellyhead and hv 13 7's 3 inch out of a 870
Dead Turkeys! That's a good combo in most 870's.
I average around 270 pellets. This is in a 10" circle at 40 yards shooting 3.5" Hevi shot 2.25 oz, #7's with a cleaned barrel. I have an 870 SM.
275-300 pellets in a 10" 40 yard circle for me with a Jellyhead .660 and Remington 870 w/26" barrel.