Thread: Projectile vs barrel length

So, I will try to explain in a different way, all the figure I will put here is fictional to a 308 caliber and you just "transfer your imagination to other calibers.

Imagine a drag race track, it is what I will call "the barrel", then you have the cars and I will call it "projectiles" and now you have the engine that I wil call "the powder".

You have a race track as long 260 meters(26" barrel) and a light little car (120grains projectile), you will load it with a "fast explosive engine) that will push this little car very fast thruout the 260 meters race track, why? Because it is a light car and the extreme velocity will take a short time to "burn" and take it all the way to the destination and still have enough "horse power" to take it further if necessary. The "down turn" of it is the track is too long so the explosive start and will only last and be effective for the first 200-220 meters (20-22") of the track but hold the speed further than that.

Then, you have the same track with a heavier car (190 grains) and need a more powerful engine to push it for the length of the hole track, so you get an engine (powder) with slower start but it will "push" the car with extreme power for a longer distance optimising the length of the track and the weight of the car.

Moral of the story: if you use the fast powder in a long barrel it will "work" for Just a percentage of the barrel, if you use a slower powder it will work for the hole length of a long. Artel but it won't be effective for a shorter barrel because, as the bullet already exit the muzzle the powder will still be burning the excess.

I will clarify my idea when I get home if necessary.

Cheers

Mac