I can't say i have experience with that combo, but I've always found Barnes load data to be pretty consistent with my chronograph readings. Are you having trouble getting the velocities you want?
I do shoot a 260 AI with a 26 inch barrel. I get 3100 with 130 gr Cutting Edge MTH and about 2950 with 140 grain ELD-M
What powder are you using for each bullet? Your load for the 120's seem a little hot compared to Barnes data, but depending on what powder you are using, another grain and a half of powder might get you there. Barnes max loads were topping out in the high 2700s to low 2800s with a 24 inch barrel. If it's still not fast enough for your liking, try Superformance. Barnes said the max load gives 2916, but be careful because they also list it as a compressed load.
Yeah id have to go back and look for the 120s I'm using hybrid 100v a follow their load data close this rifle seems to like hot loads for whatever reason.
I'm getting 2860 with 45.0 H4350 and a 130 Berger in a 24" barrel. I tried 100v and it was faster, but the H4350 was below moa at 1k so I stuck with it.
My 260 is loaded with the Berger 140 VLD, H-4831SC 45 grains cci large rifle primer and my FPS is 2677 out of a 26” green mountain barrel. Chronographed with magneetospeed