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POWDER BURN RATE

here's a link to Powder Burn Rate Chart in case someone is interested...

http://www.reloadammo.com/burnrate.htm

CVC
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POWDER BURN RATE

What is the value of the information - how do you use it?

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POWDER BURN RATE

If for example you were using reloader 19 but it wasn't giving you the performance you expected,H4350 and IMR 4831 bracket the Reloader and have proven their reliability and stabilty for decades... so check out some data for these powders.
Slower burning powders are considered "magnum powders" and perform better in 24" and longer barrels, so the IMR 3031 can't come close to the IMR 4831, etc, etc.
Just a reference chart to save a few steps..

CVC
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POWDER BURN RATE

Ok, that makes sense. If I understand it correctly, for example, I have a .243 rifle that I will reload for which I will reload cartridges.

I might look at a manual, pick a powder and load and find that I didn't get the results for which I hoped. Now, with the information you provided, I might decide to go with a slower burning powder since the barrel is 26".

Am I on the right track?

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POWDER BURN RATE

Yes, you're correct.
Shorter barrels like he Rem 600., 18.5" have little use for a slow burn powder. Most magnum rifles have either 24" or26" barrels and factory loads are slow burn for max performance.(test barrels are usualy 26 inch for magnums)
22 inch barrels all seem to have a mind of their own when it comes to choosing a powder type/charge but handle most powders with a degree of grace and dignity.

Now comes the fun of picking the right bullets, powder and charge weight for you and your rifle. The charge weight is the one you will spend more time on. Always start at minimum charge.....

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POWDER BURN RATE

Another thing to look for reguarding burning rates is in magnum cartridges. A light chg of medium burning powder's can actually jump pressure badly in the magnums. I'd heard why long ago but have forgotten. I did use some medium powder in a light chg to blow out some 7mm mag cases once. It did! Almost wreaked my rifle too!

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POWDER BURN RATE

Barrel twist is another factor that can play hell with pressures. Coupled with different bullet weights, it can get beyond confusion why some charges behave the way they do.

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POWDER BURN RATE

Ideally, you want a powder/charge that has 100% burn as the bullet is leaving the barrel.
I get the best result with the slower powders in 22" to 26" barrels. H414, H4350, H4831, H1000, Reloder 19, 22, 25, Win WMR.
H414 is not a slower powder but it does well with light for caliber bullets. Example: 55gr / 243 win stays well within pressure levels and approaches 4000 fps.
243 win, 25-06, 260 rem, 6.5/284, 270 win, 270 wsm, 308 win, 30-06 spr, 300 wsm, 338-06, 325 wsm, 338 wm.

I first discovered this when I was going through a Hodgdon reloading annual and noticing the pressure extremes between the powders for the same bullet. How the pressure in the slower powders was more gradual, yet producing high velocities. The pressure in the faster powder jump up very quickly. Leaving very little room for other variations on the round.

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