That scope and rings will add over a pound to the gun (which will help with the recoil). Add a limbsaver slip on pad and try the Remington copper solid reduced recoil slugs (1400 ft lbs of energy @ the muzzle w/a 1 ounce copper slug) and you should be in business.
Adding some weight to the buttstock will also help. I've used a piece of rubber hose, filled w/lead shot and duct taped on both ends to seal it (for a cheap, easily removeable stock weight).
One last suggestion, is to add a buttstock ammo holder (either elastic or neoprene) and fill it with 4 or 5 rounds of slugs (that adds another 6-8 ounces of weight to the gun).
The above suggestions should get the weight of that gun up to around 7-7.5 lbs thus making it tolerable to shoot w/the abovementioned loads.
Best of luck,
Jim