I have an RWS .177" that works off of one barrel break-down. It will shoot through an oil filter.
Dad recently bought a new RWS in a .177". Works the same and will drop a groundhog with no problem. I believe both rifles are around 1000 fps capable. They have more recoil than any .22 rimfire that I've been behind.
I looked up the RWS, that's a fine rifle, made in Germany. My Ruger is made by Umarex (China lol) but to Ruger specs so I hope it is a quality piece, it seems to be, up front. I was surprised at the recoil, it is significant. So far it seems to make up for it in impact tho, hits hard on a rabbit.
I did some general research on a 22short and average specs they shoot about 850 fps, with a 29 gr. bullet with 50 ft. lbs. of energy. This rifle shoots a 14 gr. bullet 800 fps and hits with about 20 ft. lbs. of energy so definitely not a toy.
427, I was looking at the Gamo real serious but the store only had the .177, I wanted the .22 so I passed on it. All they had in .22 was the Ruger and a Remington. I am amazed at the choices of air guns and ammo, it is unlimited. Some of the match grade stuff is huge dollars!
Nick