Original Model 59 feed issue

[Hawkeye59]

Each mag full of ammo I fire has two instances where the slide will lock back as if the mag is empty. Inspection reveals round in mag is positioned fwd in the mag. Any ideas on what might be causing this.

[10 X]

The round positioned forward is contacting the slide stop and bumping it upward like the follower in an empty mag.

Is this one mag or all mags? If it is only one mag, my first guess would be a weak magazine spring.

[Hawkeye59]

This is occuring with both mags that were with the Model 59 when took possession of them from my fathers estate. Suppose it could be weak spring if they date back to when he purchased the 59? early 80's. Wolf has replacement springs perhaps I'll give them a shot.