The one I have, 375 H&H has 4 screws. 1 ta rear of trigger guard, 1 in front of trigger guard, 1 in front of the floor plate and a smaller screw about half way up the fore end. Bet you missed a screw or two. The one in front of the trigger guard isn't vissible untill the floor plate is opened.

Here is a link to a not so great schematic but if you print it out it might be usefull. http://www.e-gunparts.com/schemzoom2...re64_schem.jpg It shows 4 screws attaching the receiver, and barrel.