Welcome on your first posting. You're on the right track as far as staying away from max pressure ammo, and staying in the lower velocity range. Personally, I prefer to stay under 1200 fps with everything I shoot, even in modern guns. High velocity in shot shells is overrated, except for steel.
RSTs are great, Polywad is another company that offers low pressure loads for vintage guns, though they are experiencing some difficulties with shipping and customer relations, I am hearing. I'm assuming it is a 12 ga. gun. If so, I'd stay with 1 oz. loads for all the game you mentioned, with maybe the possible exception of pheasant, where 1 1/8 might be more appropriate. Others here have much more to offer on advice for pheasants. B & P Comp Ones are a great low pressure load, attractively priced, but buy one box and try them in your gun to make sure they will fire reliably. Many guns, including MOST of mine, won't fire them reliably because of how deep they sit in the standard 12 ga. chamber. Something about the rim dimensions causes it.
Good luck! SRH
