Keesey wrote:Well my Dad got me all confused.
He is telling me the seating die is also the crimp die
I am thinking the die that is just a taper to it is the crimp die because I ran a case all the way in it and the results were not good for my brass. Way undersized the case .
Just trying to figure it out due to me going to the range today with rounds we loaded last night and not being happy with the results
Keesey-
It's awkward to possibly get mixed up in a family disagreement. I'll give the standard explanation, and you can bounce it off your dad and see what happens.
The 450B cartridge headspaces on the mouth of the case. It's like most rimless auto pistol cartridges in this regard. As with those cartridges, a taper crimp secures the bullet in the case. The usual alternative to a taper crimp is the roll crimp, as used on most rimmed pistol cartridges; these headspace on the rim. Roll crimps should not be used on cartridges that headspace on the case mouth, because the roll crimp messes up the square corner at the mouth of the case. This can allow the cartridge to enter the chamber further than it was designed to do, producing excess headspace. Several bad results can happen.
For some unexplained reason, Hornady's 450B seating die is machined to allow a roll crimp to be applied to the seated bullet. This is not desirable. That's why I indicated in the 12 December post above, you should follow the instructions for seating without a crimp. (If Hornady intended for the roll crimp to be applied when seating, then why did they put a separate taper crimp die in the set?)
Now, if your Dad is used to working with RCBS dies and auto pistol cartridges, then he's likely correct. RCBS (and perhaps other mfrs, but I haven't checked) makes seating dies that apply a taper crimp to the 32 auto, 380 auto, 9mm Luger, 40 S&W, 10mm auto, and 45 ACP. Hornady's 450B seating die is not like those RCBS dies.
Hornady could, if they wished, make a seating die for the 450B that applies a taper crimp. They don't.
(Note: Yes, RCBS also furnishes roll crimp dies for the 45 ACP and 9mm Luger; the roll crimp is especially useful when reloading for revolvers that use these two cartridges. Also, some bullets for revolver cartridges work best when used with taper crimps, so RCBS makes taper crimp dies for the 357 and 44 mags.)
The mouth diameters of the 450B differ sufficiently from the 45 ACP so that the RCBS 45 ACP Seating/Taper crimp dies will not work with the 450B.
I hope this is clear, and that you and your Dad can come to an understanding of what's going on with the 450B.
--Bob