One of my suggested 3-fer's does not appear that it will work that easily. I was really hoping that I could use the bullet as a sabotless projectile from my 45 rifles... but...
With this new bullet you can see the base is a true 451.
but the knurling is lifted to .454 to provide a positive grip on the sabot. It should be possible with a short starter to get it through - As that turns out it will not happen in my case.
I have not even tried to resize one yet... sooo...
I just resized a couple.
The bullet on the left is resized to .451... I have 3 Knight 45's - the 451 drops right down one, would be just right for the second, and will not even start in the new Mountaineer. The one on the right is resized to .452 and works well in one and will not work in the other two.
As hard as this copper is it does not re-size easily. If you resize to .452 and then to .451 it is manageable.
So at this point one of my 3-fers may not come to pass. It just might not be worth the effort.