When I was a kid, and with no idea about laws, I had the girlfriend at the times old man put a 177 Theoben GS into my 22 Lightning XL, I actually ordered the wrong one in hind sight. I had no idea how much power it was outputting I didn't care back then, I just used it for rabbits and enjoyed shooting overall... I still have it in fact, but its in bits in the loft. However, when I got round to crono'in it, it was doing 15.2... hence... its now in bits. You wouldn't believe that a simple 177 strut could bang out a 22 that hard, I know why it does, its just the shock of it when Id grown up.