7 round hold open

[checkfeo]

My 1916 DWM works great, but never loads the 8th round. Always goes to hold open after 7. Rack it back, and the 8th loads, fires, and goes hold open as it should.

My question is this: Is this just a magazine problem, as I think it is, or an indication of something else? The mag is a new Mac-gar made in Italy. Unfortunately its the only one I have.

I have tried to look through all the post on this subject, but none really answer the question. The first round in the magazine looks just like the last round in the magazine, so what is different to make it hold open?

Why does it do this? Need some help..............

Thanks to All Tom