Here's my situation...

Loading bulk 62gr bullets, once fired Winchester brass,  dillon carbide dies , and 24.5gr of Win 748 on a single stage reloader.  OAL is between 2.230 - 2.235 in

These feed fine in an Oly arms 5.56 chambered CAR97-M4.  I recently picked up a new DPMS 20" upper chambered in .223 for a known good RRA lower.  I know they are slightly tighter, but i am having serious trouble with feeding the rounds in the DPMS.  I just bought some Black Hills ammo for comparison purposes and although it is 55gr, they are loaded shorter at between 2.221 - 2.225.

fyi...both the Black Hills 55gr and my 62gr reloads work fine in the Oly...Black Hills 55gr seems to work in the DPMS as well

So I'm coming to the experts for advice...do i shorten the rounds?  do I try a slight crimp?  What am i missing thats different with the .223 chambered upper?  

Incidentally, I've reloaded and fired close to 2000 rounds using this type setup...I'm at a loss...HELP!

1.  This is NOT the reloading forum.

2.  What is the feed problem?  Bullet jamming into the feed ramp?  Failure of the bolt to lock?  

3.  Are you full-length resizing your brass, and have the resizer screwed all the way down, to ensure it is bumping your sholder back?  

4.  Are you trimming your brass to spec?

I've posted it over in the reloading forum
...

sorry