N340 will work, but N310 and N320 would be better options.
• I agree. N310 is a better "burn rate" range for 45ACP. The chamber pressure used in 45ACP is well under 20,000 psi, and so the reloader needs to make up for that with a "faster" powder.
• The idea (especially in competition) is to optimize the combustion efficiency. When the efficiency gets into the correct range, then not only are you getting the most energy for you load, but you are also getting fewer waste by-products.
• W231 is a wonderful powder in most auto pistols. It lies on the slower (cooler burning) side of "medium burn rate", which makes it very forgiving for the beginner and useful for the guy who needs "1 powder for all guns". But while the 45ACP handgun looks and operates like your popular run-of-the-mill 9mm, 38Super, or 40S&W, it actually operates at
half their chamber pressure. That's the difference, and that's what the powder has to make up for.
Chamber pressure; it's all about the chamber pressure. • There are a lot of parallels here to burring gasoline in an engine. (Think of gasoline and smokeless powder in terms of both being "fuel".) If you ever had a lawn mower, motorcycle or car where the choke got stuck ON, then the engine started to burn more fuel. Well, more fuel did NOT mean more power. Quite the opposite ! The engine started running VERY rough and started making a lot of unburned by-products in the form of thick (cough, cough, cough) black smoke.
Well in cartridge loading, we "lean out" the mixture
primarily by choosing the correct "burn rate" fuel. The amount of powder (the weight) is really the
secondary way we lean out the cartridge "mixture". The proof of this is to build some 45ACP cartridges using very slow
Unique powder. Look inside the cartridge cases after firing and what do you see ? The exact same black, sooty smoke residue that's inside the tail pipe of a vehicle that's not burring gasoline efficiently !!
Now compare fired cartridge cases where you used W231 in 9mm versus W231 in 45ACP. It will be tan in the 9mm case, while it's definitely darker colored (with more trashy residue) in the 45 case. And what's the difference? Again it's only the chamber pressures of the 2 different calibers.
Chamber pressure; it's all about the chamber pressure.Hope this helps.
