SMK 501 pellet size advice

[johnnytheboy]

Just need a wee spot of advice, I got an smk 501, tried hades, jumbo exact and bisley magnums in it and the jumbo exact seem to group better than the rest

I went to order some and noticed they came in four sizes, 5.5 - 5.53mm

Just need some advice on what should run best through a co2 gun


Thanks in advance

[Shed tuner]

if the groups aren't great, the barrel probably needs recrowning.. mine did, and accuracy was much improved afterwards

[PCPShooter]

As above, unless storage oil still in from new (you need to pull through a new barrel with a patch)
Also - 13.4's likely go well in a CO2 - (JSB RS)

[angrybear]

Buy a JSB selection testing set, has them all for you to test.

[Shed tuner]

mine loved JSB, both 13.4 and 16.0 grain, once recrowned / cleaned.