I apply a conventional roll crimp to all of my .32 H&R handloads to help
ballistic uniformity. Some cast bullet designs seated to the crimp groove may exceed the industry overall length recommendation of 1.350 inches; my Ruger will accommodate loaded lengths up to 1.455 inches, and the rare S&W Model K-32 in .32 H&R has an even longer cylinder.
Specifically, in traditional leveraction rifles, in most rifle chamberings, use of the right pistol primer routinely results in a significant improvement in
ballistic uniformity and accuracy and it dramatically reduces the risk of a misfire.
Magnum primers are sometimes appropriate for hunts in very cold temperatures or with spherical powders if a load's
ballistic uniformity (SD) is a little high.
Samples of each day's production are also shot to verify pressure, velocity and
ballistic uniformity.
Think "pillow stuffing." Years ago, published reloading information suggested puffball fillers for reduced loads where better
ballistic uniformity was needed.
I started scientifically testing load variables 40 years ago, and started checking
ballistic uniformity of carefully assembled handloads 30 years ago.
This provides good load density--an important factor in
ballistic uniformity and accuracy.
Accuracy averaged from 1.00 to 1.20 inches, with excellent
ballistic uniformity.
In the interests of gear and
ballistic uniformity, our class--comprised of assorted gunwriting and magazine types--was issued 22-inch barreled Ruger American bolt actions in .308, topped with Redfield 3-9x40 Revolution scopes.
I load for accuracy and
ballistic uniformity first, velocity second.
The loads shown in the accompanying chart were consistently accurate and demonstrated good
ballistic uniformity. These loads appeared maximum in my rifle, so the prudent reloader will reduce these charges by about 5 percent to start and then increase them carefully, watching for signs of high pressure.
Ballistic uniformity was also great, with an SD of only 4.