Trailside magazine question

[Tusc]

I have two Hammerli Trailsides. One purchased new with six magazines while the guns were imported by Sig in Exeter NH. Other than the well known slide lock issues, this gun works well.

The second Trailside is used, acquired in a group of guns several years ago. Never shot by me until today.

The second gun appears to have a much heavier barrel / barrel weight system (stamped on the right side with a circle around a W) and a Japanese Match-Dot optic. It lacks the ortho grip with palm shelf, but the plastic grip installed is still a Hammerli marked item. Perhaps someone unknown intended a bullseye gun?

Serial number is E0055115

The magazines that work flawlessly in my first Trailside will not work in the second. They do not click into place, nor feed.

Is this a known problem? Did magazines change over time? Or is this more likely a problem specific to my gun.

Serial number on the Trailside that accepts the magazines is E0017937 if they are sequential to manufacture, it is a much older gun.

Since this forum crowd was both helpful and kind in response to my first post, I thought perhaps someone here might have an idea.

Thanks in advance.

[GOVTMODEL]

Larry Carter at Larry's Guns in Maine knows everything known about Hammerli! Ask him- if doesn't know, no one else does either.