If You’ll Take The Time, The Results Can Be Impressive.
Millions of words have been written about techniques for constructing accurate rifle ammunition, but relatively little appears about making accurate handgun ammo. This is partly due to so many handgunners simply settling for plinking or blasting accuracy. Instead of dinking around with time-consuming details, they just want to load ammo and go shoot. But partly it’s because traditional handgun cases come out of a sizing die in very straight condition, unlike bottlenecked rounds sized in common dies.
Straight cases tend to result in straightly seated bullets, the most basic prerequisite for accurate ammunition.
However, a few techniques can really improve the accuracy of handgun handloads. The first step is to use consistent brass, both in wall thickness and length. This means of course, using the same brand and lot of brass, instead of range pickups.
While it’s theoretically possible to lathe-turn handgun brass, just like benchrest shooters turn the necks of rifle cases, it’s far easier to either buy consistent brass in the first place, or sort the cases with a micrometer, such as the neck-thickness setting on an RCBS Casemaster. I look for cases differing no more than 0.001 inch when measured anywhere around the mouth, because bullets fired from brass with consistent neck thickness start down the bore straighter.
As an example, I recently compared some brand-new Starline .45 ACP brass with some brand-new .45 ACP’s from another well-known American manufacturer. The Starline cases all had less than 0.001-inch difference in wall thickness at the mouth, while 23 percent of the other brand’s cases varied more than 0.001inch, up to 0.003 inch. While you can cull cases of varying wall thickness, many handloaders prefer buying very uniform brass in the first place.
All the cases should be trimmed to the same length. This is especially important when handloading for semi-autos, since most rimless rounds for autos headspace off the mouth of the case. You may find an auto shoots more accurately with cases trimmed to a certain length—and not necessarily the maximum SAAMI length.
After trimming, the mouths shouldn’t be chamfered nearly as much as with rifle cases. Instead the tiny burr (if any) around the mouth should be barely knocked off, leaving a definite flat surface on front edge of the mouth. This creates more consistent crimping and, in autoloaders, more consistent headspacing.
Some handgun handloaders also weight-sort brass, then use a tool to cut uniform primer pockets. However, neither has nearly as much effect on accuracy as neck thickness or length; I usually bypass weighing and uniforming, especially with top-quality cases. (That batch of Starline .45 ACP brass varied only 0.6 grain in weight… meaningless in the real world.)
The next step is belling the mouth, and consistent neck thickness and trimming also help here. Ideally, belling should be kept at the minimum amount necessary to easily accept bullets. Deeper belling leaves less case wall to help seat the bullet straight, and also work-hardens the brass more, affecting both case life and crimping consistency.
Primers definitely matter more in handgun loads than rifle loads, since handgun powders are much faster burning, and the space inside the case relatively tiny. The general rule is to use milder primers for small amounts of easily ignited flake powder, and hotter primers (usually but not always called magnums) for larger amounts of harder-to-ignite ball powders, but general rules don’t always apply. Some handloaders find milder primers work well with cast-bullet loads, even in some fairly large cartridges. I’ve often seen this in the .41 and .44 Magnums and .45 “Long” Colt.
Not all powder measures dispense small amounts of handgun powders consistently. Usually a dedicated small-charge measure results in more precise charges. I use the Redding Competition 10x Pistol and Small Rifle measure, with a powder hopper baffle and steel cutting edges, and the micrometer allows easy resetting to certain charges. Lee factory-crimp dies are inexpensive and work well.
As with rifle loading, a powder charge filling most or all of the available space often results in finer accuracy, due to more consistent powder position inside the case, the reason many popular handgun powders are relatively bulky for their weight. Really fast-burning powders such as Bullseye, however, also often work well in tiny charges, especially in smaller cases where the primer’s flame doesn’t have to reach far.
Bullets should be seated and crimped in separate operations. Otherwise crimping can begin before the bullet is fully seated, and one side of the mouth can tilt the bullet slightly in the case. Separating the operations is easily done with standard dies by backing the die out of the press around while seating (I use a 0.1-inch-thick steel washer), then removing the seating plug and screwing the die all the way in for crimping the rounds.
Many handgunners get by just fine with standard seating dies, but competition dies can help. The advantages depend on the brand, but usually the die includes a cylinder of bullet diameter to prevent the bullet from tilting as it enters the case mouth. Many also have micrometer markings for repeatable seating-depth adjustment. Some competition dies, such as Redding’s, don’t crimp cases, so a separate crimping die is necessary.
Experimentation with the amount of crimp can also help. The general rule has always been to lightly crimp smaller rounds, and heavily crimp more powerful rounds, because recoil can loosen bullets, especially in revolvers. In reality the tightness of the case walls creates as much (or even more) hold on the bullet as the crimp. Even heavy-recoiling revolver rounds from the .41 Magnum up will sometimes shoot better with a lighter crimp, probably because a light crimp doesn’t deform bullets as much as a heavy crimp, especially cast bullets.
The seating plug should fit the bullet shape you’re loading. Using a roundnose plug for semi-wadcutters, or vice versa, will often damage the bullets, and almost certain result in differences in seating depth. RCBS offers custom seating plugs for various bullet shapes at a very reasonable price.
How much difference does all this make? It depends on where you started. If you’re using mixed brands of brass, and not sorting it for thickness or trimming it consistently, groups will often be halved with accuracy loading techniques. If you’re using one brand of brass and trimming it consistently, accuracy won’t improve nearly as much, but just separating bullet seating and crimping into two operations often makes a noticeable difference. Of course, individual handguns will still “prefer” certain bullets and powders, but if the loads are put together precisely, odds are higher for finding a special load.
By John Barsness
4275 Highway U
Hartford, WI 53027
605 Oro Dam Blvd.
Oroville, CA 95965
Redding Reloading Equipment
1089 Starr Rd.
Cortland, NY 13045
Starline Brass, Inc.
1300 West Henry
Sedalia, MO 65301