Do different powders used in rifles vs pistols have large differences in the amount of energy they contain?
That's a really good, but tricky, question.
I'm neither a chemist or a physicist but .... well, if I am not mistaken, for instance, .... take N140 for example. N140 was the latest greatest thing 15-20 years ago. It was the result of new chemical technology ... a marked improvement over N133 and N135 with vastly superior cleanlisness features over 4895, RL15, Varget and even 4064 ... it was the end-all be-all especially for 22 cal .... except it still couldn't achieve the velocities ammo manufacturers were searching for to meet new milspec design demands.
And then comes N540. N540 was/is the solution. Higher velocities with the heavier pills WITHOUT the massive pressure spikes and while still maintaining super consistent accuracy and cleanliness goals. And how do they describe N540? (See screenshot below).
High energy.
They don't say that about N140 (they will not even publish the energy content numbers on the 100 series) ... but they do say it about all of their 500 series powders. "High energy". And it's a term being used more and more by all the major manufacturers because it is the powder descriptive equivalent of tastier, faster, prettier, intelligent, desirable, all rolled up into one for serious shooters and hand loaders.
Why is that important? Does it apply to any pistol powders?
Sure it does. All powders (which are technically classfied as fuels) are given their energy ratings using the J/g (joules per gram) energy content standards (not all are published). So whereas, let's use the 300 series powders from VV as an example, while the coatings and extrusion type may change the burn rates slightly, the energy for all of the 300 series handgun powders remains right around 4100 J/g.
Guess what? The energy content ratings for the 500 series rifle powders? 4000 J/g
So that should tell us everything. That speaks volumes. The difference between their high energy rifle and pistol powders are only 100 J/g?!?!?!?!?!?!
That also makes us stop and pause and realize once again what may be the most overriding factor, the obvious difference really, which forces these massively different loads between rifles and pistols ... is it barrel length?
Thompson Centerfire, Thompson Contender didn't think so. Neither did any of the original levergun designers.
Again ... it comes down to energy transfer. Energy transfer vs .... vs ..... vs .............. friction. Ah ha!
And once it leaves the pipe it still has to deal with friction/resistance but now it's on its own, all the energy has been transferred to the projectile and now it is dependent upon its ballstic coefficient to overcome the friction from air. That's another science.
Back to your original example.
Sure, a keg of powder has a far higher energy content than does a pound .... but that's not what ballistics are all about. Ballistics are about achieving the maximum velocity possible out of a given barrel length with a given bullet design/weight and achieving the flattest straightest truest trajectory ..... and then, after having accomplished all of that the projectile must perform properly upon impact. All of this without, optimally-speaking, producing a grievously excessive fireball as the projectile is exiting the launch tube.
What a wonderful hobby it is that we endeavor to participate.
. My hand loads are at least as accurate as them, and much cheaper.
