Sure about it being recoil this time?
http://www.rstshells.com/store/m/2-12-Gauge.aspx 12 Gauge-3/4ounce at 1100FPS. That is a 28Ga load in a 12Ga. 2 or 2.5inch, but makes no difference in an O/U or SxS. Good shell, expensive but about as easy kicking 12 as you will find. They make low recoil loads in all gauges and will ship to your house.
Winchester at one time made this one: 26Grams of shot at 980FPS. Called the Feather and felt like a .410 for recoil. Hard to find, but there are still some out there. WW distributor may be your best chance. Good for up close opportunities.
http://www.winchester.com/Products/...ced/AA-Shotshell/Pages/default.aspx?c=12It would be top of the page product No. AA12FL8
http://www.ballisticproducts.com/Fi...Low-Recoil-box_25/productinfo/3651278OZ/http://www.ballisticproducts.com/Fiocchi-20ga-20Lite-2-3_4-3_4-oz-box_25/productinfo/36520LITE/http://baschieri-pellagriusa.com/en/catalogo/cartucce+da+tiro/b_and_p+competition+one/1/index.aspxTheir Comp 1 (7/8oz) 12 is a light kicker.