Thanks that clears things up a lotThe Sl in the rifles name stands for side leverthe same as the new S510SL. The fac guns were the first of the AA multishot rifles to be fitted with side lever cocking (copied from the HW100 which was copied from the AA NJR100 / Protarget). The Exra has the same barrel length as the S410 Classic and is about the same overall lenght as the Classic fitted with a moderator. The Extra has the moderator built into the over barrel sleeve and the extra long air tube is actuallylonger than the barrel. The shot count of the Extra is between 30 and 40 @ 30fpe. This rifle is also fitted with a power adjuster wheel and if you run it at around 22-23fpe it is possible to get up to 60 shots from it althoug you do need to start to adjust the power wheel towards the end of the charge. The main advantage of the buddy bottle rifles in FAC is the shot count however this dose come at a price as the buddy bottle rifles in FAC tend to be £200 - £300 more than the Air Arms. In my local shop the most popular FAC rifle by far is the S410 Extra, which I understand sells as many as all the bottle guns put together. Apparently many shootres are put off by the looks, handling and weight of the bottle guns.
Alan