I have a new build, QC10 Colt  lower, ramped bolt, 7"barrel, Q9 buffer and Wolf Spring.  I ran a couple of mags thru it after the build, it ran fine.  I just installed a Geissele SD3G and it will not reset with the bolt with my finger on the trigger.  It will reset by hand with the upper removed.  I changed bolts with my CMMG no help.  I changed buffers and springs with my CMMG no help.  I checked install, every thing looks good.  Help appreciated.

Had a guy contact me recently having the same issue with the S3G trigger. He narrowed it down to the hammer profile not being compatible with the bolt causing it to not reset. His was not striking the firing pin upon pulling the trigger. Mine runs fine with S3G which I have had for a couple years so my only guess is that they may have made changes to the hammers which is causing the issue?

Update...  Called Geissele, and was told that the SD3G is shorter than their other hammers.  So it wont reset with a ramped bolt.  Sad part is I just had the bolt ramped while waiting for the trigger to arrive.  Best laid plans.....

I had the same issue with my build.  I sent the SD3G back and exchanged it for an SSA-E.  All is good now..

http://www.ar15.com/forums/t_3_15/643892__ARCHIVED_THREAD____Diffinitive_9mm_BCG___Trigger_compatibility.html&page=1
i tried to get this thread going but it got archived.  probbably would have saved you some time and money

Good info, I wish I had found it earlier.  Anyone have info on adding material to the ramped bolt?

im assuming you could run a bead onto the ramp and then reprofile it by hand or if someone had a fixture to put in a mill.  either way it would be a sortof hokey fix.  plus the heat would probably ruin the temper and heat treat on the bolt and ramp.  although im sure the weld would be plenty hard.  just not something id like welding on.  my suggestion would be to run the ssae.  its a fantastic trigger.  if you really want get another rra carrier and some good kns pins and run that.  you could probably even call adco and have them ramp it to less of an angle. to ensure function with the sd3g