M24 / M99 Bolt-Action Sniper Rifle Magazine 18rds

the M24 / M99 sniper magazine has a capacity of 18 BB's.
and only fit in the M24 / M99 sniper replica.

Note that with every magazine it can happen that the BB's do not feed properly on a certain brand of replica.
The advice is to try a different brand of magazine, in order to solve the problem.