bullet caliber question??

[Tone]

I picked up a box of hornady FTX bullets recently. The same ones used in hornady leverevolution ammo. I tried the hornady factory ammo in my 45-70 and they seem to be an alright bullet for what I am going to be using them for. So I was looking in the manual for a starting load when I noticed something. The bullet diameter on the box of .45 FTX are .452". In the book the bullet diameter is .458".
So it looks like I bought the wrong bullets. I decided to look at the factory Leverevolution ammo to see if that was the case. The factory ammo measures .452" at the crimp. The box of ammo is marked 45-70 govt. So shouldn't they be .458" ? Can you use either? I've asked some of my other buddies that reload and they are stumped by the factory round measuerment also.
Anybody know?

Thanks
Tone