Hey BR
I have some Rem 220 gr Kleanbore ammo in factory boxes like yours.  I noticed significant recoil differences during a chrono session a couple years ago.  Four chrono results found: 2016, 2369, 2144, 2381 FPS. 

Further inspections revealed heavy galvanic bonding between the case and bullet.  I attempted to break the bond by reseating the bullets a bit further in the case.  No luck.  The shoulders would eventually collapse. 

You might consider reseating a couple of 1000s.
Vic