I comment a lot on 3D art here on NG, but I frankly have no recommendations for you except perhaps to fix the blurriness (which gr33bl3r said was an overdone depth of field: yes, that should be fixed). As said before, the textures are excellent and realistic, particularly the scratched metal of the barrel and the gray screw between the handle and trigger guard. But the geometry is also fantastic, with flat surfaces and curves surfaces in all the right places, and a lot of non-simple shapes that you have to make out of a series of vertices.
And you BEVELED everything! That alone has me impressed.
There is one thing that really surprises me, though: this render is such high quality that surely you're rather experienced with XSI at this point. So how come we haven't seen any of your other 3D art!?