I'm not saying your load is unsafe, I'm saying it sounds crazy hot to a guy who's never reloaded before (me). But if you're able to get 2400 fps with a 150 grain projectile then I am all about it, and once I learn how to hand load I'm going to see if I can work something out like that. I never knew x39 could get that fast with a 150 gr., that's only 150 fps under a .308 with a 16.5" barrel. Such a versatile caliber.
Additionally, I believe you that your loads are too hot for the SKS, what I was trying to say is that it's cool that the Howa can shoot a lot of rounds that would otherwise be too hot for SKS'/semi autos in general. They're great little guns. I'm sure you get good groups. I bet my 527 will be pretty good for the task at hand as well. Looking forward to finding out.
Your 527 is IMHO every bit as capable as the Howa, but it's lighter and each rifle is an entity unto itself.
What may be perfectly acceptable in one rifle may be unsafe in another, even of the same type and manufacture