I have had a JP in my Bushy lower for almost 3 years. I love it! but at the range last week, firing from the bench testing some handloads, I got a 3 shot burst. When I fire the rifle from the shoulder or even from the bench with a little more aggresive hold on it there is no problem ever. When it happened, I was using a softer grip (like I would if I were shooting my 700 varmint rifle from the bench) and it belched off 3 shots. I tried to duplicate it and it wouldn't do it again. Did I basically "bump fire" it unitentionally? or do I have a problem with my fire group. I did check the disconnector by dry firing it and while holding in the trigger, pull back on the charging handle to reset it and then release the trigger to hear the "click" from the disconnector. Did I bumb fire by accident or do I have a problem?

BTW my lightweight Model 1 upper is shooting great!

i think that you nailed it.. Unintentional bump fire.  never hurts to inspect the disconnecter, though

Readjust the sear engagement per JP's instructions.  If you have lost them, go to their website and print them out.  Also check for accummulated slop in the trigger or hammer pins which can cause a change in the sear engagement.

Yep, you were bump firing by accident with that soft grip and light trigger setting.  Just need to adjust the sear engagement.