Will the magpul bottom metal with detachable mag work with my detachable mag 700 s/a ?
It has no feed rails, and can only feed rounds from the mag.
Does this magpul set up need the feed rails, or can it work in my gun ?

Anyone know ?

Have I stumped the all knowing here ??

Just saw one today that was fit to a 700 VTR. Took a few hours of inletting with a dremel on the factory stock to the get bottom metal to fit, but works great.

It will only work with the magpul stock, it's not a drop in part. You could inlet your current stock to work with the magpul bottom metal but if you did, if go with an aluminum DBM over the plastic magpul version.

Gotcha....
Had to look up that stock.
Learned something new. Magpul makes a stock for a 700 !
Thank you.