Rob,

The JSB Heavies are surprising - my '30S shoots them really well too !

My HW30S has a larger than desirable breech

It is most accurate with the below (for me) :

H&N FTT (8.65 gr.)

Boxed Crosman Premier (7.9 gr.)

JSB RS (7.3 gr.)

JSB Match Blue (8.2 gr.)

JSB Heavies (10.3 gr.)

Have fun

Best regards

Russ