Considering that you want to use a 6.01 inner barrel you should seek for high quality BBs. Moreover , as you use a 500 fps spring , you should aim for .36 / .4 / even .43 grams , deppending on how capable is your bucking of hopping this weight.
Avoid no-name brands and stick to more reputable brands : Madbull / Geoffs ( kinda overpriced , if you ask me ) / ShootOne / G&G. Always clean your inner barrel , to keep it clean and dry for the proper accuracy.
Avoid no-name brands and stick to more reputable brands : Madbull / Geoffs ( kinda overpriced , if you ask me ) / ShootOne / G&G. Always clean your inner barrel , to keep it clean and dry for the proper accuracy.