Express Calibers
In this manner they named the .45-90 an “Express” cartridge. This included one important change in rifles meant for those two .45-caliber rounds. The .45-70 Model 1886 barrels had 1:20 rifling twists. The Model 1886 .45-90 barrels had 1:32 twists. This meant — in practical effect — .45-70s could stabilize bullets as heavy as 500 grains, but the upper limit on .45-90s was about 350 grains.
This Express idea was also used in .40 calibers. Whereas the .40-65 was considered puny with a 260-gr. bullet and a 65-gr. powder charge, the .40-82 was thought of as plenty good for big game. It used the exact same bullet as .40-65, but the 17-gr. increase in powder caused velocity to go from 1,325 to 1,445 fps. I actually dropped a 6-point bull elk back in the 1970s with one shot from a .40-82. But it was a head shot from about 40 yards and so was not nearly as impressive as it may sound.
Along the way, Winchester decided they needed .40 calibers to have more bullet weight, so in 1894 they added the .40-70 Winchester to the Model 1886 options. It also used a 2.40″ case shape that was more definitely bottlenecked. Bullet weight was 330 grains. By their own figures this decreased velocity to 1,349 fps. Model 1886s chambered for .40-70 Winchester didn’t sell well and only a few hundred were made. I’ve seen and fired exactly one.
On the other hand the .40-82 was a very good seller. And to be honest, it’s my favorite of the Winchester big bores. That’s probably because the .40-82 was the first obsolete cartridge I tackled as a handloader. The rifle belonged to a friend and was the one I shot the elk with. In 1986 I traded another friend out of one that had its barrel and magazine tube shortened to 20 inches. My plan was to find an original barrel and magazine tube and restore it. Luckily I shot it first. It was so accurate I left it alone and still have it 32 years later.
Winchester’s last black powder .40 caliber was a .40-72, but instead of bottlenecking the tired old government design they fell back to the .40-70 Sharps Straight. They made it a bit longer — 2.58″ compared to 2.50″ — and loaded it with 330-gr. bullets at a claimed 1,359 fps. This was one of their introductory cartridges for the Model 1895 and was also the cartridge case their extremely powerful, smokeless .405 Winchester was based upon about 10 years later.