You always seat Barnes to be well off the lands. 3.34" might get you in trouble and lousy accuracy with the longer Barnes. Says so in the loading book, in the flyer in the box and on the website.

I have a load with a good bullet that works. It's just a Model 70 hunting rifle with a Trijicon post scope, so the pursuit of tiny holes in paper, while interesting, kinda meaningless in the real world of Deer and Antelope hunting where 400 yards is a VERY long shot.

Bullet was (I believe) a Hornady 130 grain SST.

INE, Sometime QL will also over represent slow powders in shorter barrels.

There are a few comments here referencing compressed loads when using 60+ grains of H4831.
I only see this with new/full length resized brass (Winchester or Norma), with necks sized cases having a significant gain in capacity.
I see 2,980fps out of a 222 barrelled Ruger shooting 130gr Sierra Gamekings with a load of 59.5gr H4831, either standard or SC.
I can consistently shoot 35-45mm 5 shot groups @ 200yds from both rifles I've used this load for & it works just fine out in the field too.

I haven't done much load development with 150's yet but expect similar accuracy at a lower velocity. In which case, I'll be keeping my shots under 300yds to keep inside MPBR & save fiddling with scope settings.

60 gr of regular 4831 compresses easily beccause the gr are so large, there is lots of air space.
60 gr of 4831 SC fits in the case with no problems.
Back in the day we shot 60 gr of surplus 4831 in our 25-06s (still a wildcat) with reformed LC60 NM brass that is both shorter and thicker than any commercial 270.