Beginner's Guide to Loading the .45
Date: Dec 19 2008
Reloading .45 Auto cartridges is a lesson that paying attention to the details ensures positive functioning of an autoloading handgun. When those procedures
are perfected, a handloader can then concentrate on developing and loading cartridges that shoot accurately in his gun. My Springfield Omega .45 Auto is a perfect example. When I first started handloading for it, a few loads functioned less than perfectly. Once the problem was discovered and ironed out, I shot a bunch of different powders and bullets to find some accurate loads. Now I’m banging away with the Springfield, and no target or can is safe.
Proper die settings are essential for loading .45 Auto cartridges that feed correctly from the magazine into the chamber. A regular die that seats a bullet and applies a crimp to the case in one operation can result in cartridges with varying overall lengths, which can hang up in a magazine. With a Redding seating die set up to seat and crimp in the same step with Speer 185-grain TMJ bullets, the nose of some of my bullets were actually crushed a bit. Plus bullet seating depths varied quite a bit. The reason was the crimp had been applied to the case before the bullets had been fully seated.
The solution is to seat and crimp bullets in two steps. To seat bullets, set the seating die in the press deeply enough that the case mouth is sized down sufficiently to remove the flare from the mouth and hold a bullet at least somewhat securely in the case. Then turn the seating stem into the die to seat the bullet to the correct depth. After all the bullets have been seated, back the seating stem out of the die and turn the die into the press to apply the desired amount of taper crimp.
Adjusting the die back and forth all the time is a pain. After awhile I got so tired of doing it I started using a separate Redding taper crimp die. When using an RCBS Piggyback progressive press, I just add the crimp die in the station after the seating die.
Most reloading manuals state .45 cartridges should have only a slight taper crimp applied or no crimp at all. The theory is .45 cartridges headspace off the case mouth and enough of the rim must stick out so cartridges can be positioned correctly in the chamber.
However Carroll Pilant of Sierra Bullets says, “With most autoloading guns the cartridge headspace is actually set by the extractor holding the case head against the bolt face. So case mouth diameter is really not that important.”
When the short, fat .45 cases are fired, they expand outward. So fired .45 cases are usually always shorter than minimum length. Only when the cases are resized do they lengthen somewhat, and that will still be under the maximum allowable case length.
I measured the length of three fired Winchester cases; they were .840, .830 and .800 inch, which is well under the .888 inch standard minimum length. After the three cases had been run through a Redding carbide sizing die, their lengths measured, in the same order, .891, .890 and .889 inch. Those lengths are well under the established .898 inch maximum length for the .45.
Reloading manuals do not state exactly how much a taper crimp should reduce the diameter of the case mouths to a case to keep a bullet in place. Pilant sets the amount of taper crimp by testing a few cartridges to make sure the bullets do not move. He first pushes the nose of a bullet in a case against the bench top. He measures the cartridge to determine if the bullet has been shoved deeper into the case. If it has, he applies a little more crimp until the bullet remains tightly in place. Next he places a cartridge in the bottom of his gun’s magazine and then tops off the magazine. He fires all the cartridges, except the test cartridge. He measures it to see if the bullet has moved. If the cartridge has remained the same length, he considers that amount of crimp sufficient.
Using the same brand of cases is essential to get that same amount of taper crimp on all cartridges.
“Some brands of cases have thick walls and some brands have thin walls,” Pilant says. “When you size those cases, the thicker ones are going to have a smaller mouth opening than thin cases. That’s going to affect how hard bullets seat and the amount of crimp the cases have.” For instance, my Springfield Omega shot accurately with Speer 230-grain Total Metal Jacket roundnose bullets and 8.5 grains of Accurate No. 5 in Remington cases. Just as importantly, the gun cycled the load without a hitch. I used a Redding Competition Bullet Seating Die to seat the bullets. This die put no taper crimp on the cartridges, only sized down the bell on the case mouths. I thought I had found a great load, so I loaded up 50 cartridges with a mix of case brands with the Speer bullet and Accurate powder. When seating the bullets in the different case brands, there was a definite difference in the pressure on the loading press handle. Some bullets seated with next to no pressure and some with resistance.
“That’s close enough,” I thought. “There’s no need to run them through the crimping die.”
Well, it was almost close enough.
The next time at the range the cartridges cycled into the chamber, but about three cartridges out of every magazine stopped the bolt just a fraction of an inch from fully closing. I finally gave up. I took the remainder of the cartridges home and ran them through a Redding Taper Crimp die. The die put a lot of taper crimp on the cases. In fact the thicker cases required a rather hard downward push on the press handle to apply the crimp. The crimps reduced the case mouth rim diameters to .470 to .466 inch. Those cartridges fully chambered without a snag. However, using all one brand of cases would have made much more uniform cartridges.