I have pondered teaching this old dog new tricks. I have been reloading for many years, but think I can update my ways. Please tell me. What bullet is best? Primer? Powder? Also on crimping, taper crimp? How tight? I use factory crimp die. Any ideas or experience will be helpful. Thank you in advances post/question is for info/feedback for all ACP and cartridges that use a taper crimp. Example 9mm, 40S&W, 45acp.

The best bullet is the one that does what you want it to do, and you didn't say what you were doing with them; target, game, self defense, etc.
Taper crimp; NEVER on a case that headspaces on the mouth; you are accomplishing nothing and potentially creating a problem. NO cartridges should use a taper crimp; for me. It is a good way to loosen a bullet. How tight should your bullet be? if you can't push it back into the case with firm pressure with your hand, then it is tight enough. You adjust that with the inside expander plug diameter.
Factory crimp? NO; don't crimp at all on cartridges that headspace on the mouth. I don't want to belittle your many years of experience. But there are better, proven, ways.

The only thing you use any type of crimper for on a straight rimless pistol cartridge is to make the belled mouth go back straight; no more.
You can actually make the bullet looser by using a taper crimp die.
Taper crimp dies were invented by the die companies so they could sell more dies, not because there was any need for them.

If you look at the SAAMI cartridge drawings, there is a very tiny amount of taper crimp. Some where in the area of .0001" This helps feeding.

On the 45acp, loading a 200 gr lswc of .452 diameter, a bit more taper crimp may be needed for the rounds to fully chamber in a match grade barrel.

I suggest seating and taper crimping in 2 separate operations. This will reduce, eliminate any shaving of a lead bullet.

SAAMI

Trim Length - Have never needed to trim a 45 acp case, the trim length has an effect on a taper crimp, but even more if using a roll crimp on a revolver round.

Mixed brass will have the most variation in length. The taper crimp die must be set on the shorter case of the lot.

This will allow all cases to be taper crimped, but the longer ones will get more.

Some 45 acp will need as much as .002" taper to fully chamber.

That taper of one ten thousandth of an inch, is going to be hard to achieve when SAAMI allows .006 (Six thousandths) variation in the brass, and .003 in the bullets. And the chamber is allowed .004 variance.
I have never found the need for a crimp of any kind on .45s, and I didn't start reloading for it yesterday.

quote:

I use factory crimp die.

Post sizing may be a problem with lead and plated bullets. Making the bullets diameter smaller.

Thanks for the input and advice. I will be utilizing these ideas.

This isn't that hard. 45 ACP is very forgiving. Mixed brass is fine. There are many good bullets: the 200 lead SWC, 230 JHP, 185 JHP... Use a slight taper crimp until the rounds will cleanly into a case gauge (a must have). Length variations have no material affect. I did about 20k rounds this year without issue