I have an Air Arms S400K that is.....

by Otony, Tuesday, August 02, 2016, 04:09 (2974 days ago) @ Paul

....an English Market gun, that is to say it is set up to run at 12 foot pounds. It is a pcp rifle, and on the side of the stock is a small adjustment valve that allows one to vary the pressure according to the weight of the pellets being used. By the way, this one happens to be a .22 caliber rifle.

This adjustment valve is quite necessary as the English police are in the habit of carrying a muzzle-mounted chronograph in their vehicle. If you are observed using your rifle, you are subject to having a its power level checked (without warrant), and woe to you if it is even a smidge over the limit. Fellows with spring operated guns typically set them up for 12 pounds using the lightest pellet available, so that the use of anything heavier will not bring it over the limit. If you tune the rifle to achieve the limit using a heavy pellet, you are sure to be over if switching to lighter weights.

My reason for purchasing a rifle set up that way was to gain the adjustment valve, as full power American Market rifles lack that useful feature. I had the internals tweaked by Airguns of Pomona (?) so my overall power level was raised, but even then it is less than a full power gun. By using the adjuster, I'm able to fire about 100 times at the lowest setting, and about a dozen times at the highest.

Guess where I obtain the most accuracy?

Otony