i had a .22 uk patriot , or maybe it was a kodiak, that had a theoben gas ram. shot 888 fps almost consistently with box premiers and 1/2 inch groups at 50 yards. that got sold and sent to mexico. i cant remember who it was (maybe david slade) , but there was only one guy you could get a theoben gas ram from back then and i think you had to send your gun to him. i remember some great power-tuners of that gun were very discouraged that theoben gas rams were too hard to get - that was back in 2011. they are expensive, but the theoben gas rams are very effective. maybe you can find one (maybe theoben isnt a company nowdays - hadnt thought of that).............shoot.........this reply might not help much. sorry. - paul.