Just a rule of thumb in the industry, it's wise to NOT put darts in ANY airgun of ANY type that shoots over a velocity of 500 fps. It "can" damage the barrel, the darts are thin walled and can rip apart before leaving the barrel of a high powered rifle.
If you have anything shooting UNDER 500 fps, you should be fine, but keep them out of the high powered ones. They are designed for recreational use, mainly at dartboards.