Barrel length?

[noggin buster]

Picking up a 870 compact JR for my wife.  The jr comes with 18.5" barrel.  Is that to short? Will that short of a barrel effect patterning.  I plan on running an ssx with fed HW 7s to start .I would like to make it a true 40 yard gun.

[mikejd]

I have an 18" barrel and can put well over 200 in a 10" at 40 yds.