My 0.177 HW99 has had the usual fettling including a Delrin top hat, spring guide and a PTFE piston sleeve. It currently has the standard HW mainspring without preload washers, and shoots JSB 8.5 gn. at 11.25 Ft.Lbs.

I would like to trade some power for a smoother firing cycle, thinking that an alternative, softer mainspring would be a better solution than cutting a coil or so off the existing mainspring.

Is fitting a softer mainspring the best approach, and if so could someone suggest an alternative mainspring?

Thanks and Best Regards,
Bill.