While I don't know the part number off hand, I do know that the base is the same for the Omega and Triumph. Readily available. I got one with my Impact when I bought it.
As for low recoil loads, I use a 260 grain precision rifle "extreme elite" with 100 grains of Pyrodex. It is nice and mild to shoot if you are an experienced shooter. Also a big time slayer of deer and other like sized animals. A very accurate pure lead bullet. I also shoot 400 grain cast pure lead conicals with 100 grains of Pyrodex and they have enough recoil to get your attention. They get the attention of whatever they hit too!
If this is your first venture into shooting and you want a really low recoil practice load to get you used to the trigger pull and how to hold the rifle etc. , consider a patched round ball with 50 grains of Pyrodex. This is a great practice load for 50 yards or less and kicks almost not at all. It is the load I introduced both my kids to when they wanted to shoot black powder rifles. You will have to wipe the bore with a damp patch between shots to make sure the patches around the ball stay intact, but it makes the gun a lot more fun to shoot if that is your intention.
I had to remove the rear sight on my Impact in order to get my scope correctly mounted. It was way too far back and I kept getting pounded on the bridge of the nose. NOT fun at all! Another quirk of the Impact is that mine would not open all the way with the ramrod fully seated in the stock. I wound up removing a very small amount of material from the front underside of the stock where the two parts hinge together to allow room for the rod. Just a tiny half circle the size of the ramrod cut with a dremel tool was all it took.
My Impact shoots really well and it it light and handy. I like it better than my Remington 700 ML by far.
