I thought that all air rifles has to be sub 12ft/lb with the heaviest of pellet available?
I know of a case where somebody local to me was using 14s in an air rifle putting out 11.8ft/lb, and he got pulled. The police checked the rifle on their calibrated kit with 16s and it went to 12.6ft/lb, he was done. The police said that maybe he was set for 14s but the fact is he COULD have had 16s.
The police can use whatever pellet they like mate, if this takes your rifle over the limit then be prepared to suffer the consequences....hence why most sub 12 air rifles are in the low 11's to al