MB2
You must using a pump shotgun like a Rem. 870 or Mossberg in order to worry about recoil.
I have been shooting the #4 BK for at least 12 yrs now and never a problem with recoil with a Beretta 303 auto. But I do know that I will never shoot Slugs or BK in the 870 anymore, in fact I have retired it.
I have used the PACT recoil pad for shooting my 300 Mag years ago, it really tame that rifle down, made it much easier to shoot.