So how hard does sequester hit DoD?

Hard enough to make the generals flinch, and flinch a lot.  According the Aviation Week, the Pentagon figures Congressional deadlock will persist up to and maybe thru the 2016 election.  They are preparing for current and even lower funding until 2016 and beyond.  So
  The Air Force is talking about retiring 552 older aircraft, about 10% of the fleet.  On the chopping block, A10 close air support tank buster , KC10 tanker  and MC12-W (the Beechcraft King Air fitted out for reconnaissance). 
  The Army will loose 18% of its soldiers. 
  The Marine Corps will loose 7% of its soldiers
  The Navy drops from 295 ships to 255-260 ships.

Reducing the size of the Army and Marines means that in event of war, they have to work harder.  For Iraq and Afghanistan we were able to send the troops on one year combat tours and then rotate them back stateside.  If we run out of troops, then the combat tours get longer, they get extended, and the rotation home goes away.  It's tough on the troops, and tough on their families, but we have done it in the past.  In WWII troops enlisted for the duration, and nobody got rotated home after a one year combat tour.  (except the Air Force got rotated home after 50 missions, if they lived that long)