I hate to say it... it's not something that one wants to hear, nor is it something one relishes telling someone who's asking an honest question about such a thing, but... it depends on the gun as to whether the 7s or 8s are more reliable.
As to actual physical differences, they are as follows:
7 round follower is convex, 8 round follower is concave.
The two use slightly different springs, both made for Wilson under exclusive contract with Wolff. Wolff does -not- sell them directly, they only supply to Wilson.
The 7 rounders have the 'witness slots', which is the feature that makes Wilson's mags look unique. INstead of holes, they have 2 slots cut in the side for round counting. 8 rounders have the same exact same slots as the 7s, but -also- have a tiny hole witness hole drilled for the eighth round. Other than that, the tubes are identical.
A word of warning: Larry Vickers posted in the custom gunsmithing forum about mags, and he mentioned that Wilson's plastic baseplates are breakage prone. With his experiences, he darn well knows what he's talking about, and my experiences correlate with his. Plastic baseplates blow. When ordering mags, make sure the part number ends in 'C' (example, 47DC is an eight round mag). The C denotes low profile steel baseplates. They also have a thick steel baseplate if you have a mag well on your gun.
Hope this helps!
TRB
[This message has been edited by TRB (edited 02-24-2001).]
