Some of the longer/heavier bullets ,if you seat the bullet to mag length,have the problem that all of the cylindrical body of the bullet is pushed into the cartridge case before the load is to mag length..so then when you finish seating to length the ogive is actually down in the neck,and you can see space between the case mouth and the bullet.
You can load the Hornady 75 gr HPBT just fine at mag length.The Hornady 75 (or 77?) gr A-Max will have this problem.It won't work at mag length.
Generally,the bullets over 80 gr,that must be single loaded,are used by match shooters for targets 600 yds plus,where the wind bucking power pays off .These match shooters often use 69 to 77 gr bullets loaded to mag length for their 300 yd targets. Unless you intend to single load for long range shooting ,you might want to pass on the 90 gr bullets.
As you are developing your load,I suggest buying and loading in small quantities. Pulling bullets is no one's favorite activity.
I shoot informally in wide open spaces.For myself,Ifind the price and BC ,along with the performance I get with RE-15,make the Hornady 75 gr HPBT my first choice bullet.Honorable mention to the 77 gr SMK and the Nosler 77 CC.
I found the 69 gr HPBT's great ut of my 1 in 9 bbl using Varget.
As I buy Varget in 8 b jugs,use it in 308 with great results,I REALLY wanted Varget to work out for my 75 gr load. Eventually I had to accept my chronograph gave a clear advantage to RE-15. I did not notice significant accuracy advantage for either. You can get charge data from the Hornady load book AR match page.
One off topic tip that may save you some trouble later.Read your die instructions. DO NOT assume it is correct to screw your seating die down to contact the shellholder.
The die has a crimp function built in.Contacting the shellholder will apply the max crimp the die is capable of. Unless your bullet has a very generous crimp groove,there is no place for the crimp to go. This translates to an excessive force being applied to the bullet via the seater stem.
The cartridge case is unsupported inside the seater die. The force causes the shoulder to collapse The case bulges out at the shoulder.You likely will not notice it till you try to chamber such a round. It will get very stuck part way into the chamber. Your shooting day will be messed up.
To set your seating die: Put a piece of brass in the shell holder.Ram up. Back off the seater stem a few turns.Screw the die body down till it contacts the case mouth. Back it off some.A quarter turn will do. Now,note the gap between the die body and the shell holder. Try to find a washer or feeler gauge,something so you can reset that gap the same. A little + or_ does not matter,you just need to accurately repeat the gap.
You may get better concentricity if you put that washer/gauge between the shelholder and the die and put a little load on the die before you set the lock ring down on the press.
Now set your seating depth