This statement is inaccurate.
Trail Boss is a fast burning pistol powder that is bulky. It should NEVER be confused with or labeled as a "weak powder" when it comes to burn rate or the pressures it produces.
9.3gr will fit into a 44-40 case with a 200gr bullet and produces 15,182psi, 4,000psi beyond the 11,000psi max., with velocities at a low 1,200fps from a carbine.
However, slower burning fast burning powders like Reloder 7 don't have enough time to fully burn when used in revolvers thus the pressures remain low with a case capacity load like black powder, as well as poor velocities.
ANY name brand commercially manufactured 44-40 cartridge is safe for any firearms chambered for it that is in good operating condition. The reason why modern 44-40 factory ammo is so @#$%^ weak for this very reason.
For some reason folks are not "stupid enough" to shoot hot 45 Colt loads and Hot 45-70 loads in weak action firearms but yet I guess folks are too stupid to know the difference when it comes to the 44-40 hot loads. Same rule applies.
Colt and most other revolver manufactured didn't "approve" smokeless powder loads in revolvers until 1909. Why? Know one knows for sure, all speculation...but I can assure you that the very thin cylinder walls are a hell of a lot weaker than any rifle's action.
By 1909, revolvers were using "normal" smokeless loads while Winchester's Model 92' rifle was using "High Velocity" factory loads since 1903.
Same rules apply today when it comes to loading 44-40 for use in revolvers vs rifles as it did in the 1920's and 1930's.
Sharp once wrote in his 1937 hand-loading manual...
" The 44-40 is capable of excellent performance when loaded properly for handgun use. If, however, one endeavors to combine loading for both handgun and rifle in this caliber, he is destined to meet with only mediocre success. As in all other dual-purpose cartridges, the factory loads are only a compromise at best. Smokeless-powder loading for handguns requires a much more rapid-burning type than loading for rifle use, as the short barrel must burn all the powder if satisfactory results are to be achieved. In addition, rifle cartridges can be loaded to a pressure of about 30,000 pounds in this caliber, whereas the same load in a revolver would be more or less disastrous."
For example:
If your goal is the best velocity from a revolver, keep the following in mind.
When the moon, stars and all of the planets line up perfect...
(20" carbine length testing barrel)
9.3gr of Trail Boss produced only 1,250fps at the highest pressure of 15,182psi while 26.5gr of Reloder 7 produced 1,432fps at a much lower 11,373psi.
There is certainly more than one way to skin a cat but sometimes history is the best policy.
Pistol powders have always been dangerous when improperly used in 44-40 handgun loads but are best for 44-40 handgun applications when black powder is not desired. Both Bullseye and Unique have been around since 1898 and 1900 of which both perform extremely well in the 44-40 handgun application.
On a side note, back around 1909 (ironic date?), the US Government's loading machines kept dropping an occasional "double charge" of Bullseye in their M1909 45 Colt loads. Most of the time they would blow the gun with the first shot. DuPont came up with a replacement powder called RSQ. One could fire six consecutive double charged 38 caliber loads before it got ugly. Being "rescued" by DuPont, Major K. K. V. Casey requested it be called "RSQ"......Resque! The powder was dropped two years later with the Model 1911.
44-40 smokeless powder transition years
44 Winchester "Two Peas In A Pod" - Smokeless Powders Transition Years
