Just got my M4. It came with the standard modified choke, patterns very well w/ OO buckshot. When shooting 1 oz slugs, it shoots 5 inches high even with the rear sight completely bottomed out. (at 25 yards) A buddy got his the same day, mod choke, same slugs hit dead center with rear sight adjusted about 1/2 way down. I broke the shotgun down and reassembled, no change. Customer service was very helpful, but before I send it back in, I wondered if this is a problem seen before and if there are any other things to try here first. Also, what is the optimum choke for this shotgun if best balanced performance is desired with OO buck and slugs, interchangably?
Thanks for any advice,
Steve