Just a tidbit for some of us to digest on. I was looking at the powder burn rates on Hodgton.com and came to find out, in larger fire arms, that slower burn rates seem to generate more fps. Maybe psi but I have no way to test that. Now are my observations true?

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that slower burn rates seem to generate more fps.

welllll...not exactly....

What you'll find is that the ratio of bore diameter to combustion chamber size is the critical issue....

For example....the 17 Remington operates quite well with H-414 because the bore diameter divided by the combustion chamber size is small.....but in the .458 Winchester where the bore size is relatively large and the space requiring filling by burning gasses is quite large as the bullet moves down the barrel....then one needs a faster burning powder to fill the quickly expanding "boiler room"

If one moves to the .460 weatherby where he has a very large case capacity to hold a lot more of the slower burning powder then one can actually make use of the slower burn rates.

The relationship between powder burn rate and case size is misleading as the caliber is actually more important....

Generally speaking.....as the caliber goes up, one needs a much larger boiler room to make use of the slower burn rates....and it's not always available.

that explains a bit on the rifles I shoot. 30-06 6.5X55 are my 2 main ones 6.5 be my all time favorite!
It seemed to me in these I would be using slower burn rates to push more fps.

My post was extremely over simplified.....and frankly the relationships are exponential as volume increases with the square of the bullet radius...further..the faster one fires a bullet the volume again increases faster.....

It's worth noting but as for me that's the end of it.....find a sound manual and go by it!

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Originally posted by James Kain:
that explains a bit on the rifles I shoot. 30-06 6.5X55 are my 2 main ones 6.5 be my all time favorite!
It seemed to me in these I would be using slower burn rates to push more fps.

Funny you mention that as both the 30-06 and 6.5X55 do well with slower burning powders.
Slower powders are, of course, at their best when pushing heavy bullets. It's also worth noting that both calibres will do well when fed anything form IMR 4895 to IMR 4831!

Well now we can see how I came up with that "observation" when that's all the most I load for besides my M1 Carbine that shoots pistol powder. I need more dies :P Well need a bunch of stuff but dies to start. Also a concentricity gauge.

Funny thing is, most people who want to get in to shooting the 6.5mm bullet that I have met want to shoot smaller lighter bullets. Then here I am and maybe never will see me shoot anything under 140GR or maybe as low as 130GR. Before I took my rifle to the smith I was checking out the 160GR RN from hornady and my own hand cast in the ball park of 165GR. But when its back, i m starting with a clean slate to start the hole thing over.
So I see more fun doing the thing we love hand and had reloading and that is....

Sorry about that I should be asleep so I ramble..worse then normal

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Originally posted by vapodog:
My post was extremely over simplified...

And easy to understand, plus correct.

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....find a sound manual and go by it!

Going outside what the Powder Manufacturers have Tested is not a good idea. Some folks actually believe they are smarter than the Factories with $$$Millions$$$ invested in Test equipment. But, it always catches up to them eventually.