How to pick powder??

[bench]

I called alliant today about the RL17 I wanted to use for my Weatherby 240 Magnum and was told it was a bit to fast and they said to use RL19 because it is a bit slower on the pressure curve

So I related to burn rate but they related to the pressure curve.
So how does one find that info for different powders and different bullet weights
I hope I explained that correctly as I am way over my head
Is their a chart that explains pressure curve vs bullet weight.

 

[jonbearman]

Quickload supposedly can provide you with the imfo but is user unfriendly unless you are real into computers only from what I have read on this site. Which reloading manuals do you have?

 

[XTR]

I've read a comment in the past that discussed choosing a power by "burn rate" and that it's not necessarily tied to the peak pressure and rate of pressure increase, which is what you are actually trying to control.

 

[CatShooter]

I called alliant today about the RL17 I wanted to use for my Weatherby 240 Magnum and was told it was a bit to fast and they said to use RL19 because it is a bit slower on the pressure curve

So I related to burn rate but they related to the pressure curve.
So how does one find that info for different powders and different bullet weights
I hope I explained that correctly as I am way over my head
Is their a chart that explains pressure curve vs bullet weight.

It is a complex subject, so don't worry about being over your head.

First off, you and the guy at Alliant were talking about the same thing from opposite sides.

For a given cartridge and bullet weight, faster powders will have shorter pressure curves, and slower powders will have longer pressure curves.

You can use very fast powders, but you will have to reduce the amount (and therefore the performance of the load) because equal weights of fast powder will produce very high pressures.

And in the same sense, powders that are too slow for the cartridge/bullet combination, will not be able to reach full pressure so full performance cannot be attained.

To sum it up, for a given cartridge, heavy bullets need slower powders because the bullet is in the barrel longer and present more resistance to acceleration, whereas, lighter bullets need faster bullets because they are in the barrel for less time, and offer less resistance to acceleration.

For any combination, there will be a range of powders, some on the fast end of the spectrum, and some on the slow end... most manuals will offer you a choice of those powders that are reasonable to use.

 

[MrMajestic]

QuickLoad is your friend.

 

[savagedasher]

Burn rate is rated off a gr weight . Ball powder will have a different fill then stick powder. OL will tell you close to the % amount of fill.
Hunting I like 90+%of fill. Target I like 100% plus fill.
My Dasher on QL is 100.9% full.
Without a long drop tube with a slow pour I can't seat the bullet with low neck tension. Larry

 

[artbosco]

I called Alliant today about the RL17 I wanted to use for my Weatherby 240 Magnum and was told it was a bit to fast and they said to use RL19 because it is a bit slower on the pressure curve

So I related to burn rate but they related to the pressure curve.
So how does one find that info for different powders and different bullet weights
I hope I explained that correctly as I am way over my head
Is their a chart that explains pressure curve vs bullet weight.

Personally, I don't care about burn rates or pressure curves. All I want is the best load for my rifle or pistol's cartridge. Whether I start with a particular bullet or a particular powder, it doesn't matter.

Keep doing what you just did.

Call the powder and/or bullet techs at their respective companies when you want the latest info on loads. They test, test, test, test and retest for you, the customer. Ask them to email you some loads. They've never turned me down and I've usually received the mail within ten minutes.

Take advantage of THEIR healthy research budgets and inter-industry competitiveness for your dollars. Continue what you just did and you'll be head and shoulders above the crowd, way above the crowd. .

 

[MagnumManiac]

I was shown/taught to read a few or even several reloading manuals, particularly the powder and bullet manufacturer you're using, and look for the powder that produces the highest velocities in all manuals checked. This powder will nearly always be the most efficient and give the highest load density. In fact, any powder giving the top 3-5 highest velocities should work the most efficient per grain to velocity.
Burn rate charts are a very LOOSE guide as to what powder will work in a given cartridge. It should only GUIDE you to similar burn rate powders, if H4350 works well in one case, then IMR4350 & 760 should also work well. One simple fact remains that should dissuade anyone from using them to extrapolate loads from, BURN RATES ARE NOT CONSTANT FROM ONE CARTRIDGE TO ANOTHER, some powders even perform much faster or slower in certain case capacities and case shapes, such as straight walled rifle cases, fast powders burn slower in these style cases.

Hope this helps.

Cheers.