Determining how much slower a powder is via published load data ?

[LAKEMASTER]

I was gifted 8 lbs of 800x

I'm having trouble finding info on load data for 3006

Is there a way to figure out how much slower one powder is to another?

For instance. My CBH#4 lists
40s&w
150 gr bullet
5 gr unique@ 980 fps
6.8 gr 800x @1085 fps

200 gr bullet
4.5 gr unique @ 882 fps
5.7 gr 800x @ 916 fps

Do these numbers mean. 800x is ~15 % slower then unique.

If i wanted to roughly match load data like this how can i calculate it.

[JSnover]

800X seems like more of a pistol/shotgun powder (IMR website won't even recommend a load for it in 30-06). You might be able to convert but you might be better off trading it for something else to feed your rifle.

[Hick]

If you look in the Lyman Cast Bullet handbook your will see loading data for fast powders such as 800x. 800x has a burn rate somewhere in the vicinity of Herco and SR 4759 (use at your own risk). In any event, max loads for 30-06 with these powders is small-- order of magnitude 17 grains. Great if your goal is cast shooting at fairly low velocities, and if you are careful not to double charge. For general use, though, and higher velocities, 800x is not a good choice-- you need something lots slower, like 4064.

[runfiverun]

800-x is slower than herco.
but herco is a good starting point for using 800-x in places it's not listed.
800-x doesn't meter well so it's often overlooked in many uses.

[LAKEMASTER]

I guess i was trying to future out a substitute #.

Like if my book says 15 gr unique - i subsitute 17 gr 800x.

[runfiverun]

I have tried to do a direct half way to this half way to that comparison before and found out I was much better off by using the faster powders data and just starting half way through it.

I see a lot of powders in the herco area that flip flop back and forth between one step faster and one step slower throughout their cartridge range so it's hard to predict anything other than the faster powders data is the one to use until I see it acting like the slower one.
you can add more powder but it's hard to step back from a mistake.

I know we are only talking about 30/35-k here but your also looking for accuracy.

[paul h]

Burning rates are relative, not absolute. Which is to say that while powder A may be faster burning that powder B in cartridge X, operated at a certain pressure, if you switch to cartridge Y powder B may be faster burning when operating at a different peak pressure than powder A. Also some pistol and shotgun powders are susceptible to pressure spikes when used in rifle rounds with lots of air space.