It sounds to me like your stock is too deep through the action area. If you have a caliper for reloading take a measurement on your old stock from the top of the bedding to the bottom of the fron screw hole. If that measurement is shorter than your new stock you may have a bit of reshaping to do on that stock.
I've never re-stocked a Browning precisely because of this reason, the fit of that magazine has to be pretty darn close in order for that thing to feed.
