Been there, done it........thought i had a case, even had an independant test done at the cost of £900 which showed my gun was firing under the limit.....the police got another test done and proved that my gun was capable (with heavy pellets) of firing at 11.2 avg.......was found guilty and got £1000 fine, and forfeiture of the gun. Unfortunately its an absolute crime...your either guilty or not guilty ie: no middle ground....
11.2 is under the limit?..Think you will find Most if not all BSA S10 go over the limit soon after being bought .The reg fails on the gun and they tend to go to 13