Swift bullet question(s)

[ApacheHunter]

Hey all. I've been reading a few different cookbooks such as Hornady, Nosler, Speer, and Swift. I've noticed that in some of the cartridges that the Swift has significantly lower velocities for some calibers.

The one that is of the greatest note to me is the 280 Remington. That's what I have been reloading for the most but want to try the 150 scirroco. The velocity is way off compared to some other bullet manufacturers. Is it just me or could have to do with the old 280 Remington/7mm Express chamber pressure thing from way back? Could it have anything to do with the hardness of the bullets? I'd like to try the 150 scirroco but it looks kinda weak.

Thanks for the help and any info.