Correlation between bullet weight and powder burn rate

[Trigger71]

I'm deciding on a powder for a load work up for 10mm.  I have on hand 135gr Nosler and 155gr Speer JHP.  I have a  large variety of powders to choose from and wondering about a correlation between the light weight bullets and the burn rate of various powders.  Is there a connection as far as rule of thumb? 
When I move to loading 180/200gr, would a slower powder be an advantage?

[The_Shadow]

Well the longer barrel lengths yield more velocity from almost any given pistol powder.  With the heavier bullets to slower powders give a good push and the faster powders can spike quicker in pressure.
I think the powder's volume for case fill is an important factor for accuracy more than the need for the highest velocity.  That being said those solid copper/brass bullets tend to be as long as some of the heavier cup and lead core as well as cast bullets.  That leaves very little room for some powders and a good balance of burn rate verses the usable case capacity is needed to work within the pressure parameters.  Therefore 10mm can work across a wide variety of powders with all of the bullet weights.

[Trigger71]

Thank you.  My angle is to not simply accept a manuals recipe, but understand the principals behind it.  It seems the 10mm has such a wide variety of uses, bullet weights, velocities, that the options (compared to other cartridges) are a bit overwhelming.  If I can get a baseline of principals, I will be more confident on load development. 

In reference to my other thread about the Delta's chamber, I am leaning towards a heavier bullet and a slower powder for a more stable and controllable pressure.  Would there be any validity to that?

[Graybeard]

In reference to my other thread about the Delta's chamber, I am leaning towards a heavier bullet and a slower powder for a more stable and controllable pressure.  Would there be any validity to that?

Not necessarily, in my experience. Best accuracy comes from consistent velocity, which comes from consistent pressure yield. Slower powders yield more velocity, but not necessarily more pressure. As Shadow mentioned, faster powders peak faster. You may get to the same max pressure from a powder like Bullseye as you do from Longshot, but the Longshot load will yield more velocity.

All powders have their own characteristics when it comes to burn rate and ignition. Some work well over a wide range of bullet weights, like Power Pistol, and some don't. That's not even factoring in the variables between guns, such as barrel length, bore diameter, lock time, etc. But that's why most of us hand load. Figuring out which powders, bullets, work best for us in our guns.

The type of bullets can also affect powder performance as well. Cast bullets will always seal to the bore better than a hard FMJ. You can see the difference in high speed video. Much more ejecta leaves the bore prior to the bullet with FMJ than cast bullets. Loading manuals always list lower charges for cast bullets than jacketed of the same weight.

So to sum that all up, consistent pressure/velocity/accuracy comes from matching the right bullet type/weight to the characteristics of the powder and primers you use.

[CtYankee]

The most important rule of thumb is: Slow velocity, fast powder; fast velocity, slower powder. I'm assuming you have a  semi-auto, most of the "experts" I've read say that fast burn powder peaks before the slide starts to move, mid burn powders keep pressure on the slide until the bullets leaves the barrel. One the "experts" is an person on Rugerforum.net who was a gunsmith for 50 years. Power Pistol was developed for semi-autos, but I have found it works very well in revolvers (I have a 10mm revolver) and use it for everything, even 45 Colt. It works for a broad range of bullet weights and velocities. Very slow magnum pistol powders are unusable in semi-auto cartridges, you can't fit in enough powder in to gain any advantage - in fact, somewhere on this forum I read a post by a guy that tried using H110 and that was his conclusion.