a reloading question

[fogducker]

ok it,s that time of the month for a dumb question
when reloading i see in the manual,s that theheavier the bullet get,s the less powder you use....you would think the heavier the bullet the more powder you would need..
can some one explain this to me?i know it,s the way to do it but i do not understand why

 

[Gatehouse]

It's about pressure.

Heavier bullet will increase pressure, larger doses of powder will increase it too.

 

[SDC]

Exactly; putting a heavier bullet into the equation increases the pressure, so if you put a heavier bullet AND a larger powder charge into that limited volume, it's going to boost the pressure so much that something's got to give somewhere.

 

[Rifleboy]

There are limitation like bullet length against the length to rifling of the barrel, length of the magazine and also pressures.

Fore example, .300WSM come in short bolt action (most of the makers use 1-10" twist) and is perfect with bullets between 165-180gr, however if someone reloads and like heavier 220gr bullet something has to suffer and in this case is the velocity (powder) taken by the longer bullet.
In my opinion, they should make this caliber in 1-11" or be more generous with the bolt size.

 

[ricciardelli]

Say what??

 

[joe-nwt]

er, never mind!

 

['Boo]

There are limitation like bullet length against the length to rifling of the barrel, length of the magazine and also pressures.

Fore example, .300WSM come in short bolt action (most of the makers use 1-10" twist) and is perfect with bullets between 165-180gr, however if someone reloads and like heavier 220gr bullet something has to suffer and in this case is the velocity (powder) taken by the longer bullet.
In my opinion, they should make this caliber in 1-11" or be more generous with the bolt size.

What are you talking about??

 

[guntech]

ok it,s that time of the month for a dumb question
when reloading i see in the manual,s that theheavier the bullet get,s the less powder you use....you would think the heavier the bullet the more powder you would need..
can some one explain this to me?i know it,s the way to do it but i do not understand why

It is because modern smokeless powder burns progressively. That means when you fire the cartridge as the powder begins to burn the pressure increases and the powder burns faster and as it burns faster the pressure increases more and it burns even faster.....

if you were to draw a graph of powder burning rate and start out with a gradual curve upwards, very quickly the line would be drawn almost straight up.

....so if you have a hot load for a given weight of bullet and increase the powder charge or the bullet weight you will exceed the safe working pressure very quickly.

Never try and figure out loading data on your own - always consult the data in a published reloading book.

 

[Rifleboy]

[QUOTE='Boo]What are you talking about??[/QUOTE]

Take two bullets in .30-06

150gr Part and 200gr Part

Load both with same powder like H414/55gr and what you gonna see.

First the pressures with 200gr gonna exceed the max pressure of 58800psi by 4000psi,
second seating the longer bullet gonna be a chalenge with some powders and some rifle designs

With 150gr Part for .30-06 the pressure is going to amount only to 45000psi way less then Pmax for .30-06

Here is an example for 200grain

 

[Rifleboy]

Take two bullets in .30-06

150gr Part and 200gr Part

Load both with same powder like H414/55gr and what you gonna see.

First the pressures with 200gr gonna exceed the max pressure of 58800psi by 4000psi,
second seating the longer bullet gonna be a chalenge with some powders and some rifle designs

With 150gr Part for .30-06 the pressure is going to amount only to 45000psi way less then Pmax for .30-06

Here is an example for 200grain

http://www.imagestation.com/picture/sraid200/p0ba4a3e20972fdb4e206614a0422f7f4/f07c7382.jpg

I hope this graph helps
Greetings,
Peter

 

[fogducker]

ok ..got it..thanks all
cheers
Don

 

[joe-nwt]

Take two bullets in .30-06

150gr Part and 200gr Part

Load both with same powder like H414/55gr and what you gonna see.

First the pressures with 200gr gonna exceed the max pressure of 58800psi by 4000psi,
second seating the longer bullet gonna be a chalenge with some powders and some rifle designs

With 150gr Part for .30-06 the pressure is going to amount only to 45000psi way less then Pmax for .30-06

Here is an example for 200grain

See what happens when you get the software before the experience?

No offence, of course.