870 xpress super mag hevi 13

[Tadpol37]

870 xpress super mag. Hevi 13 #6. Jellyhead 665
At 35 yds counted 203 in the 10. 35 yds is my preferred maximum shot distance.  Went out to 40 just to see what she'd do and had a considerable drop off to 78 in the 10. Anyone have any suggestions on such a drastic drop in numbers?

[Mizzouhntr]

Thats a huge dropoff.. and im a super newbie on patterning a shotgun..my 870 sm hates a dirty barrel. I lost 20-30 pellets each shot. Maybe a dirty barrel? I went from 250s in #6 longbeards to 150s 4 shots later. Cleaned it up, decided on 5s and got 196 at 40 on a 26 degree day. Shot pattern posted in this forum

[tha bugman]

870 xpress super mag. Hevi 13 #6. Jellyhead 665
At 35 yds counted 203 in the 10. 35 yds is my preferred maximum shot distance.  Went out to 40 just to see what she'd do and had a considerable drop off to 78 in the 10. Anyone have any suggestions on such a drastic drop in numbers?

I have seen the same thing in guns/chokes.....they shoot good @30 and in...move back 10 yards and they just blow up...the pattern I mean