Loading for a 35 whelen in a 750 Remington carbineand loading 200 grain Hornady round nose with 57 grains of RL15, the data said with 60 grains its around 2675 which is with a 24 inch barrel. Somewhere along the way from 60 grains with24 inch barreland my the 18 inch carbine the extrapowder will muzzle flash and no velocity. Anybody broke out the chrno and andgot an estimate where that long vs short barrel place is?

with the powders available today the problem you are asking about is pretty much non existent you are talking maybe a 50 fps difference, 100 fps at the absolute most between a 18 and 24 inch barrel. but now if you are talking going with 57 grains instead of closer to max that will play a big role in velocity loss. with 57 grains or 60 grains of RL15 you wont beable to notice any difference in muzzle flash. also RL15 is a fast enough powder that you wont get much muzzle flash anyway now if you are talking RL19 there might be a noticebale amount muzzle flash. IMO i would just work up a good load and not worry about it at all unless you are concerned with recoil??

Actually, regarding smokeless powders, irrespective ofa powder's "burning rate", the great majority of powder charges in modern, CF rifle cartridges are completely consumed by the time bullets have travelled four to six inches down the barrel. (Long before the bullet reaches the muzzle!!) Therefore, the powder charge that will produce the highest velocity is the one that consists of the greatest mass of powder which can be burned in a given cartridge without generating excessive pressures. (ie,the most fuel. )

This is usually the slowest-burning powder that will produce the maximumPERMISSIBLEpressure in that gun with the bullet in question. NOTE THAT THIS IS TOTALLY INDEPENDENT of the length of the barrel!

Of course, the longer that pressure can push on the bullet, the higher the velocity will be when the bullet leaves the muzzle, so, yes, barrel length has an effect. BUT, under normal circumstances, NO POWDER is still burning when the bullet exits the muzzle, unless the powder was loaded to a density insufficient to permit normal burning - (too little powder....)

For more definitive info on this subject, I refer you to this months' HANDLOADER Magazine. Read about Phil Sharpe's actual experiments on barrel length vs MV..... It is pretty eye-opening for most people!

Thanks, Might have to go get that mag.