So something along these lines:

A few shapes to build the upper body part with a Loft:





Then in the side view, one ellipse profile and a path, to make the handle with a sweep:





So now you've got 2 solid pieces that are pushing through each other like this:



Select them and run Construct > Boolean > Union to fuse them together into a single solid. That will create an edge where they intersected each other, select it here:



Then you can run Fillet to round off that edge:



Then it looks like you'd want to do some kind of a sweep to build a curved cutting surface to kind of scallop out the sides, check out the scalloping step in this desert eagle example for something similar:
http://moi3d.com/forum/index.php?webtag=MOI&msg=3321.17

- Michael

Probably after you cut some the scalloped side parts out you'd hack off the back of it to get the kind of profile you want like this: (here doing a boolean with just a line as the cutting object):








Then everything would get filleted at a smaller radius than what was used for the handle/body one to round off the sharp edges.


Hope this gives you some ideas!


- Michael

oh wow thanks for the nice reply, yes that might be a good way to start the base of the model, will try and post my progress