Upper Body

I. Incline DB Press
--A.9 x 55's
--B.8 x 55's
--C.6 x 60's
--D.4 x 60's

II. Chin-ups (supinated, wide grip)
--A.10 x BW
--B.7 x BW
--C.5 x BW
--D.4 x BW

III. Seated Military Press
--A.10 x 35's
--B.8 x 40's
--C.3 x 45's

IV. Shrugs
--A.8 x 255lbs
--B.8 x 265lbs
--C.8 x 275lbs

Comments: Improving on everything BUT chin-ups. Is there anything I can do to improve on them? Should I try adding more resistance to try and break that plateau?
It's not because I can, but because you couldn't if you tried.