The early BX-25s were problematic. A google search for "BX-25 magazine problems" will get you multiple links to the Rimfire Central board, where the issues and fixes are frequently covered.
Cleaning and lubing helps, but the follower spring spool is too big for its axle, so there's wobble and the follower gets jammed. A cut-down .22LR case bushes the spool to correct size.
Ammo (technically, bullet) configuration also causes some problems due to a "pinch point" in the cast feed lips, especially with Blazer. Slightly opening the pinch point with a fine file allows the bullet nose to rise enough to feed.
Using mag loaders with force instead of finesse results in rimlock (an upper rim being behind the lower rim), resulting in jamming up the follower.