yep 80 grains with the 245 is max. Its bad enough with 100gr of powder, 150gr is worse! LOL.
Seeing how your groups are very good right now. My guess is that the bore butter is gunking up. Just swab between shots with alcohol soaked patches or simply bring a bottle of windex and spray the patch down and swab away. You dont need that bore butter crap! Its no good.
I would get a bucket of HOT soapy water and pump it through the barrel until you get all of that bore butter oil.
Once you dry the barrel, use some Rem oil, dampen a patch and run it down the bore * using both sides of the damp patch* Give it a few minutes to dry and then run one dry patch to mop up excess oil.
Just get all of that bore butter out and scrub the barrel clean!