150gr Powder Max Load Question

[reelamin]

I'm new to this muzzle loader hunting.  I have been reloading for decades...yes I'm old but I still can not find and answer to this question.   Why does 150gr seem to be a maximum load with muzzle loaders....but you don't see bullet weight factored in.   Center fire always and I mean always you see a reduced powder volume the heavier the bullet.  This is with the same powder not different powders.  Why do you not see a reduced powder charge for muzzle loaders even though the bullet weight increases and decreases?  Ballistically/Pressure speaking...something is wrong somewhere.  There is no way 100gr of powder with a 250gr bullet creates the same pressure as 100gr of powder with a 350gr bullet.   So, we should be able to load more than with a 250gr than a 350gr and maintain the same pressure level...right?

[Dan-o]

Having shot thousands of max loads thru my muzzleloaders, I'm confident in stating that I don't know.

Tagging.

[reelamin]

The "Typical 150gr is Max" load?  Serious question...really trying to figure this out.  Gotta wonder why Muzzy companies dont publish pressure data....I know they have the equipment and are using it.   

Having shot thousands of max loads thru my muzzleloaders, I'm confident in stating that I don't know.

Tagging.

[Buckblaster]

I'm with you, I'm big in reloading too, and have wondered the same thing. 

[Killmore]

I would venture a guess and say it probably has something to do with how the pressure is achieved?

[Sabotloader]

I would venture a guess and say it probably has something to do with how the pressure is achieved?

Pressure and liability...

[reelamin]

Probably...but barrels, actions, are proof tested for a maximum pressure capability.  Regardless of how it gets to maximum it is still the maximum.  For example the 40 S&W pistol cartridge has a very "spikey" pressure curve compared to the 9mm and 45ACP.  A lot of the first pistols were having some parts beaten up due to the pressure curve/unlocking/locking rate.  This had nothing to do with the pressure rating of the barrels or brass just how quickly and at what pressure the gun was moving at. 

I would venture a guess and say it probably has something to do with how the pressure is achieved?

I don't know how to quote two people on the same reply.
Sabotloader....no question it comes down to liability in todays world.   I know I'm overthinking this like always....but there has to be a legitimate explanation based on science/ballistics/pressure. 

[reelamin]

So, I fired off a few emails and Ramshot replied super fast.  I messed up on my first email so I got some clarification.   Needless to say for me they were very timely in their response but also generalizing the answer and not really being clear. 

I sent:
Hello I have a question I can not seem to find a solid answer for.   I have been reloading centerfire for +40 years and just started muzzle loader last year. I have been using your powder with great success. I can not understand why powder weight/volume is exactly the same for a bullet of 245gr and 250gr. I have never experienced a heavier bullet with the same powder weight charge without severe pressure issues. Why is it different for your powder....well any black powder/substitute black powder? Does the pressure not increase the heavier the bullet used over the same powder charge?

They replied:
In Blackpowder powder weight (grains) does not equal volume. They are two different types of measurements.  I know everyone says that they use “xxx” amount of grains in their Blackpowder rifles but they are incorrect, they should be saying volume. As all Blackpowder measure are in volume.

So with Blackhorn 209 yes you will see a pressure increase, but it will not have severe pressure issue as you stated. Remember that Blackpowder is different than smokeless powder.  Yes you will have a pressure increase using BH209 but it will not be severe. But also you will not see a pressure of performance increase if you add to much powder to the rifle. As the powder column gets longer, you have less barrel length for your bullet to travel and pick up the energy from the powder before it exacts the barrel. Thus you gets lots of unburnt powder.

I sent:
Don,  I am so sorry.  I read your reply and it did not make as much sense to me as I expected.  I then re-read my email and I am an obvious idiot.  I sent two different bullet weights of 245 and 250gr.  I intended to use 245 and 350gr for bullet weights.   My question is the same in regards to the 105gr difference in bullet weight.   Sorry for the error.

They replied:
Ron,

No worries. Even with the 105gr difference you will not see severe pressure. You will also still use the same load data 80 volume to start to 120 maximum.  Blackpowder is designed not to produce the massive pressure wave you see with smokeless powder. The max pressure you should see using Blackhorn 209 are around 30,000 psi.

[Oh Mah]

Because the muzzle loader can handle it due to the fact that the "case" if you will is thick steel and not thin brass.the difference in pressure is not enough to become dangerous between the weights of different bullets.

[T-Bone]

In black powder loads, more is usually not better. In fact, the trade off for that line of thinking is usually a lot of unburned powder, more recoil and poor accuracy. Muzzleloaders kill by kinetic shock from a heavy piece of lead; thus, trying to turn your muzzleloader into a .220 Swift is not a wise choice.

In my T/C .54 cal, 90 or 100 grains (by a B/P powder measure; ie. volume) is  plenty and very accurate.

[CP]

Thus you gets lots of unburnt powder.

That's what I've found; once you hit a certain point adding more powder only makes more smoke and flame and actually slows down the bullet as the mass of unburnt powder adds to the weight on the bullet.  I don't know what is happening with pressures but my SWAG is pressures are limited as well to well below safe levels with modern muzzle loaders.

[andersonjk4]

I would guess, and this is only a guess, that the pressure difference between a 245 grain bullet and a 350 grain or even a 450 grain bullet is really not that much different.  The pressure is created by the friction of the bullet in barrel.  In a ML the friction of the bullet coming out of the barrel isn't much more than the friction pushing the bullet down the barrel.  And the friction difference between the lightest bullets vs. the heaviest bullets is pretty negligible because the difference in length for the short fat ML bullets is very little.   The relative lack of bullet friction in a ML doesn't allow a bunch of pressure to build behind the bullet and therefore you get to a point where adding more powder doesn't get you an appreciable gain in pressure and therefore velocity and results in a loss of efficiency (un-burned powder). 

[reelamin]

Thus you gets lots of unburnt powder.

That's what I've found; once you hit a certain point adding more powder only makes more smoke and flame and actually slows down the bullet as the mass of unburnt powder adds to the weight on the bullet.  I don't know what is happening with pressures but my SWAG is pressures are limited as well to well below safe levels with modern muzzle loaders.

Good thought, I have heard the same thing and agree in theory but disagree in experience.  My experience over the years....(very limited with muzzle loader) is I have never found that point where I don't continue to gain velocity and pressure before I run out of case capacity or parts start coming apart regardless of the powder choice (center fire).   I have experienced the same with muzzle loader even if it is not burning all the powder.   The average velocity gain per 10gr powder increase is less and less but where is it? 

You have reached that point so what was your data just before and after that point?  Super interested in knowing where that is.   I dont want to load any more powder to find out where that is with a muzzle loader.  I have loaded well past "maximum loads" and continued to gain velocity.  Sure it is less efficient not as accurate...but it is still gaining velocity.

This may be one answer that is hidden in the vaults of who knows where and why.   Enjoyable discussion as usual.

[kselkhunter]

Barrel length is also a factor in terms of unburnt powder.  For example, a CVA Accura LR has 6" more barrel length to burn powder than an a CVA Wolf.

[CP]

Thus you gets lots of unburnt powder.

That's what I've found; once you hit a certain point adding more powder only makes more smoke and flame and actually slows down the bullet as the mass of unburnt powder adds to the weight on the bullet.  I don't know what is happening with pressures but my SWAG is pressures are limited as well to well below safe levels with modern muzzle loaders.

Good thought, I have heard the same thing and agree in theory but disagree in experience.  My experience over the years....(very limited with muzzle loader) is I have never found that point where I don't continue to gain velocity and pressure before I run out of case capacity or parts start coming apart regardless of the powder choice (center fire).   I have experienced the same with muzzle loader even if it is not burning all the powder.   The average velocity gain per 10gr powder increase is less and less but where is it? 

You have reached that point so what was your data just before and after that point?  Super interested in knowing where that is.   I dont want to load any more powder to find out where that is with a muzzle loader.  I have loaded well past "maximum loads" and continued to gain velocity.  Sure it is less efficient not as accurate...but it is still gaining velocity.

This may be one answer that is hidden in the vaults of who knows where and why.   Enjoyable discussion as usual.

In my rifle using triple seven, 300gr bullets and musket caps - that point is between 110 - 120 gains (vol) depending on temperature.  I back off to 100g with no noticeable loss in vel.  That's my load:  100g 777, 300gr  .429 bullet, green sabot.  Maybe there is something better and faster but I haven't found it.