More powder for smaller grain bullet?

[Walkalong]

Rule3 was just trying to help. If anyone was being negative it was me. I have always considered this a simple concept and one that my first reloading manual explained in a simple to understand way. To me anyway.

The heavier bullet builds pressure faster because it takes more energy to get it moving from a standstill. That build pressure faster, so for the same powder you must use less of it. With a slower powder than one used with the lighter bullet you build pressure more slowly, get the heavy bullet moving, then get more velocity because of the greater amount of energy in the larger charge, within pressure limits of course.

Run into a big beach ball and watch it jump away from you. Run into a big ball full of water and see who is affected more, you, or the ball? You just built up a lot of pressure upon collision, where with the ball of air, it moved away never letting the pressure build up.

That's the same reason slower powders can get more velocity with bullets, instead of running full speed into the ball, you ease up to it and steadily increases pressure until it gets it moving. That's a great exaggeration of course, but is the basic idea.

 

[Lost Sheep]

Why?

This forum is called "The High Road" for a reason. We aspire to a higher moral character than some forums.

We don't always achieve it. But we do try.

illegitimi non carborumdum

Lost Sheep

p.s. When I find a question that has been asked and answered, I try to post a link to the best of the previous threads. Some questions will repeat over and over, for as long as there are new participants to handloading. Personally, I don't mind.
edited to add: New participants to shooting and reloading is a good thing for the continued existence of those activities

 

[Lost Sheep]

Pressure

Hinted at, but not pointedly, is the fact that all smokeless powders operate within a specific (and different for each powder) pressure range. Above or below that range, performance can me erratic which can be merely frustrating or dangerous.

So, you want whatever charge of powder to be within that powder's performance envelope.

A heavier bullet's inertia allows a lighter powder charge to get into that pressure range. A lighter bullet's lesser inertia takes more powder to get into that pressure range than a heavier bullet requires.

Also, the weight of the powder is included in the weight of the ejecta discharged, so can be partially included with the weight of the bullet.

Welcome to the forum and thanks for asking our advice.

Lost Sheep

 

[buck460XVR]

Some questions will repeat over and over, for as long as there are new participants to handloading. Personally, I don't mind.

I don't really mind either. As for the "use the search function" and the "Google is your friend" aspect, sometimes it's easier just to ask a simple question and get a simple answer. Kinda what these forums are all about. In the same amount of bandwidth as it takes to chastise a newbie for asking a question that has been asked before, it can be answered. If it wasn't for the same questions asked over and over again, there'd be very few new posts on any gun forum. If there were no more "what gun for bear?", "what's the minimum caliber for deer?", "can I use magnum primers in place of standard primers?" and "the dumb guy at Wal-Mart!" threads, this place would become a ghost town.