Air Arms Owners Club

Hi guys, my S410 was chronoed and only shooting 8.1f/lb. a member at the club removed the dome head screw and adjusted the transfer port allan bolt around 4 weeks ago and it was showing 746 ft/sec on the chrono which he told me was 10.4 ft/lb. The reason I left it at that power is because when he tried to get it to shoot around 777ft/sec with every pellet over the chrono it just kept rising in feet per second and was over 800 ft/sec It just so happened that the club were chronoing everyones guns yesterday and my S410 was only shooting 664 ft/sec 8.3ft/lb!!!! Does anyone have any Idea why it is dropping power? its a 2014 rifle.

Have you lost a breech seal.

BBF

Had a similar problem with my s200. After buying it second hand found that the former owner had removed the anti-tamper and done some adjustments. The transfer port screw had become loose and moved every time the rifle was cocked and fired. I solved this by putting a longer grub screw in that stuck out the side and put a lock nut on it making it like the mk1 s200. Not looked at an s410 so not sure if you could do the same.

Ray

Not long sorted an s510 with what seems to be the same problem, the power adjust screw can wind itself in and obstruct the airflow, I just put a new one in, sorted. Ask Julian to send you a couple. Rog

Thanks for the replies guys. BBF, I had it in for a service so I assume it was done but who knows? I'll give it a couple of weeks and try another chrono. The thing that is annoying is that it is a lovely rifle but as I shoot HFT the holdovers change all the time and I would just like to have a consistent power output. I'll let you guys know what happens over the next couple of weeks and maybe get a better idea what's happening.

They can pop out at anytime. Load a pellet and when you fire check for any air leaks around the breech area. Breech seals can be seen if you look closely.

BBF