Shooter Has Question About .45 ACP Crimping Methods

Thank you for your excellent article in the May issue on .45 ACP reloading. However, there is one point in the article which I find confusing. You write concerning the bullet seating and crimping stages: “This crimp should be applied in a separate step and must not be part of the seating process.” I know some die manufacturers like Dillon make the seating and crimping two separate operations, but some, like RCBS, make the seating and crimping in one die. Are you able to provide some type of documentation or proof, not someone’s opinion, that keeping these steps separate makes for a more accurate load? If not, perhaps you could offer some explanation as to why the separate steps are better.

I own RCBS reloading equipment. Should I now abandon my die sets in favor of purchasing dies with separate seating and crimping dies? What would you do?

-Geoffrey Brecher
Santa Rosa, California

The conventional thinking has always been that seating the bullets and applying a taper crimp in two separate steps creates more accurate ammo. The thinking is that the bullet is less likely to be deformed or damaged and that the process is more consistent in the crimp tension. However, you are correct that RCBS offers a three-die set that seats the bullet and applies a taper crimp in one step.

According to RCBS Ballistic Engineer Warren Cloninger, RCBS did a blind test on this several years ago. They loaded ammo using both the three-step and the four-step process. The ammo was then sent to several top shooters and gun writers to be tested in a variety of guns. The results came back with the three-step process actually being more accurate than the four-step process. Based on this data RCBS decided to sell its die sets with a three-step loading sequence for the .45 ACP that seats the bullets and applies a crimp in the same action. Cloninger did note, however, that RCBS still offers a separate crimp die and that it sells quite well. So, the bottom line is if you are happy with the performance of ammo you are loading with a three-step process, there is no reason to run out and buy a different set of dies.

Besides, by eliminating one step you can load more ammo per hour—why make more work when it’s unnecessary?

Cartridge Annealing Question
I read the referenced article with a great deal of interest. I reload for two cartridges which I am changing and expanding body taper and moving the shoulder forward, i.e., 22 Hornet to the K. Horner and the .257 Roberts to .257 Ackley Improved (40-degree shoulder). It is unfortunate, I think, that I have already loaded all of the cartridges that I want to fire form. Should I go ahead and fire-form these and then anneal the necks and shoulders to avoid neck splits? Any advice in this would be appreciated. I would hate to have to pull bullets, dump powder and kill primers, anneal necks, and then reload. I have done some of the .257 and have had no split necks, but I have not reloaded and fired them. I have experienced a very few split necks with the Hornet. I have fired some of the expanded brass and have not had any necks which split.

-Charles Lamar
via Compuserve

Never attempt to anneal loaded rounds. Shoot up what you have, then work annealing into your reloading sequence.

Burning Question
I’ve read several reloading article in Performance Shooter, all of which have alluded to “fast burning” or “slow burning” powders. I understand that different powders burn at difference rates, but I’ve always wondered how the rates are controlled.

-John Warner
via the Internet

The total surface area of the powder charge and chemicals applied to the powder regulate its burning rate. Small-kerneled powders, which have more surface area per unit of weight than larger powders, will burn faster, unless deterrents are applied. Deterrents are chemical coatings applied to powders that slow their burn rate. However, the combination of kernel size and deterrent application make it impossible to judge a powder’s burning rate by how it looks.