I recently got my new shotgun, a Beretta 1301 Comp 24". I intend this to be my "lots of things" shotgun. Due to my previous history with a Benelli M1 that I shot good with when I was fat and after losing 100 lbs of fat, could not hit anything with, I thought I should pattern this before taking it hunting in the fall.
Well, I patterned it and I was shooting about 6" high and 2" right with it. So, I took the stock off, switched the shims to SX cast, 65mm drop from the factory DX cast, 60mm drop and added the 1/2" spacer back giving me 14" LOP, from the 13.5" LOP previous.
I patterned it again and I am good enough on the elevation but I am STILL shooting to the right, even with cast on. So I tried shooting it "free recoil", or as close to as I could rig it up. I put it on bags and just sighted down the rib and pulled the trigger without holding the forearm or grip. That put me dead on for "windage", elevation was a little high but that was probably because of how I was trying to stay off the stock. (Cycled fine by the way)
I also tried out my Dad's early 80's vintage Browning BPS (14.5" LOP, factory stock w/Limbsaver) that I have always seemed to shoot the best with as well as my brother's Maxus (14.25" LOP I think factory stock settings). The Maxus doesn't fit me at all. The toe of the stock digs into my arm and it is very uncomfortable to shoot.
As shown in the results below, I shoot the BPS similarly to how I shoot the 1301. My brother's Maxus has the most centered pattern but it is also with a Mod choke rather than a full, not sure if the greater spread at 13 yards might be masking the center. I also feel I pulled down and right on one of the shots, my wobble was more with the Maxus and I got a true surprise break on the trigger.
All of the shots were roughly 13 yards from the muzzle and the BPS and 1301 were both shot with full chokes with a mixture of low brass Remington/Federal/Win #7.5 shot cheap promo loads (might have been a #8 mixed in). Three shots per target.
I also had my brother shoot my gun and other than him shooting really high with it (big fat head), his pattern was well centered.
I think it is something I am doing with my form/head position/trigger pull/recoil anticipation/etc, but I am not sure what.
Do any of you sporting clays experts know what I am doing wrong without actually seeing me doing it wrong?
For reference I am 5'11, 155ish lbs, 29-30" waist, narrow face/head.