I am a big fan of Barnes bullets and now some other monos, but the 280 Nosler is a classic and virtual perfection. I would not change a thing except might try the LRAB if better BC is wanted. The X bullet is more likely to keep a straight line of penetration if bone is encountered but this side of Buffalo or Giraffe I don't think there is enough difference to be concerned about.
But there is a chance the Barnes might be more accurate so worth a try for that reason. I think I would go straight to the TTSX or LRX in any caliber under 33 for starters. R26 is doing good things in the 280AI for me 3200 for 140s and 3150 for 150s. It is just not a good powder for extreme heat.
If anything the Nosler may kill quicker but hard to prove by me.
I'd be a bigger fan of Barnes if seconds that shot just as well as firsts were available for about half price (or even less sometimes), like the Noslers are from SPS.
