I would like to see quantified, objective data presented behind his powder burn rate claims.
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Go look at any reloading manual. For any given cartridge and bullet weight there’s an optimum powder that gives a maximum velocity within accepted pressure limits. There will be faster and slower burning rate powder that still function.
Bring your chronograph and firearms and come on out and we can test as many as you want.
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The manual will list one powder that is max velocity within safe pressure limits for all barrel lengths? (for a given bulllet weight)
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No. Vihtavuori for example might test in a 4” barrel.
My offer is for you to come out and stroke the handle on my reloading press and try different powders and chronograph the velocity in your firearms.
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I’m just looking for someone who makes claims about powder burn rate in different barrel lengths to back up those claims with data.
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Charts with relative burn rates are listed with on a lot of reloading sites:
And it would stand to reason that with a shorter barrel, you would need a faster burning powder because you want all of that powder to burn before the bullet exits the barrel. Any powder that fails to ignite before exiting the barrel can no longer contribute to bullet velocity (but may increase muzzle flash).
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I suggest searching around the reloading forums, you might find that assumption incorrect.
Which is why I simply ask those (esp posting articles) who make a claim to have numbers behind it.
Things aren’t always what you expect.
Edit: For example, you have to get into average pressure over the length of the barrel, vs peak pressure, and a fast powder might peak high and early and drop off while a slower powder might have more “area under the curve”. It is almost like comparing a peaky high HP engine in a car to a torque monster that makes power everywhere and has a lower peak but still pulls harder down the 1/4
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Very true. But I read it simply as wanting to make sure all the powder burns in the time it takes before the bullet exits the barrel, therefore desiring a faster burn rate. Maybe I misread that.
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The second to last sentence mentions powder burn rates so I believe a person could optimize a load for a given barrel length.
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Which would be advantageous when using barrels shorter than the common length barrel or test barrel length.
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It’s hard to tell taken out of context but I believe you are referring to where I say a slower powder may result in higher velocity due to greater average pressure over the length of the barrel, even in a short barrel, when compared to a powder that spikes a high pressure fast but has less on average over the course of the bullet’s path through the barrel
There is a lot more to internal ballistics than peak pressure
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There’s a point of diminishing returns. I was trying to find a different email from Hodgdon but I already deleted it.
People who get a carbine for a pistol or revolver cartridge sometimes think they can utilize the additional barrel length for a substantial velocity gain. It just doesn’t happen because of the expansion ratio and limited cartridge capacity.
It’s on my list of things to test, but it seems logical that using a fast powder in a short barrel wouldn’t have the same velocity penalty as a slower powder.
And if that’s not at least part of the equation, then how do you explain the “short barrel” factory loaded ammunition?
It would be easy to test if it was just a bullet alloy hardness difference by pulling factory bullets from short barrel and standard ammunition. Load them over the same charge and gel test for comparison.
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Different bullet design that’s intended to open reliably at lower velocities.
Could even be…slower burning powder?
Marketing.
That’s what I’m talking about in the last paragraph of my post above.
I don’t know what all goes into bullet design as it relates to expansion but I’m willing to bet it’s more than just the hardness of the metal(s) used.
Still, would be interesting if a person could pull bullets from say “gold dot” and “short barrel gold dot” both from Speer in the same caliber/cartridge and test some of them in calibrated ordinance gel going the same velocity (might not even have to pull them if you play with barrel lengths and distance to the target).
Not sure that will tell us anything about powder burn rates vs barrel length directly though
If the pulled bullets displaced the same volume of liquid in a laboratory beaker, and if they showed similar expansion and penetration when fired at the same velocity, I would call them close enough to be the same. If the volume displaced is less then I would assume a denser softer alloy was used.
Assuming they test reasonably similar in volume and penetration and expansion, powder burn rate is the next logical thing to investigate.
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For me it would be cheaper and easier to do a 90 round test over a chronograph. Pick three powders. Fast, medium and slow from one manufacturer. Test in three different barrel lengths. Record the average velocity of ten shots through each.
I wouldn’t have to buy factory ammunition to disassemble or calibrated gel for testing. And my interest is in the relationship of powder burn rate and bbl length.
I just mentioned comparing
Pulled bullets from short barrel vs not as another way to validate the findings.
Having owned and shot many 45’s over the years in training and competitions i always had the best reliability and accuracy with 230gr.
I have 2 45’s in my collection one a custom built 1911 and the other a Glock 21 that both have upwards of 100k on them. The 1911 still runs great and super accurate but the Glock has definitely seen better days as far as accuracy.
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Lost me at a 300fps velocity increase (in a .45) form .3” of barrel-I’m calling BS here. On the planet where I live you’d do well to get an extra 300 fps from a .45 with 3 full inches of extra barrel. At .3” the difference in velocity should be less than standard deviation between rounds.
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