Propellant burning Rates changed?

[Alk8944]

From a different thread:

Originally Posted by DWalt

"From personal experience (I worked at Hercules before it became Alliant), if the canister powder's name is the same, so will be the ballistic performance. Canister propellants made for sale to hand loaders are blended to produce very similar ballistics performance forever even though the formulation may have changed slightly. i.e., barring any degradation due to age or poor storage, Bullseye or Unique made in 1920 will perform very similar to performance of the same powders made last week. That does not mean that reloading recipes remain constant forever."

Everyone who believes that propellants like 2400 and Unique have changed need to read and understand this! Several years ago I had a conversation about exactly this subject with one of the engineers at Alliant. What he said was "If we had changed anything about a powder we would have called it something else!"

Nothing else makes any sense!

2400, Unique, Bullseye and other Alliant propellants made today are exactly the same as when they were made going back clear until they were originated by Laflin and Rand! Except for 2400 that wasn't introduced until the 1930s.

Published loading data from the 1930s, '40s, and 50s is just as valid as it was then using todays manufactured propellants of the same name as earlier.

The frequently repeated story that burning rate of current powders is different than 50 years ago is absolute B.S. Manufacturing processes may have changed over time, but they still produce propellants functionally identical to those same propellants made long ago. Anything else is internet myth!

 

[rwsmith]

Could you imagine the liability......

...if a powder company makes "Whatsit" powder and changed the specs on it and somebody blew up their gun using 'old' data for "Whatsit" powder?

 

[Rule3]

The powders may be the same, but the tested load data may vary


Which was stated in the original post by DWalt but not highlighted by this OP.


"That does not mean that reloading recipes remain constant forever."


Look at some of the data in nuclear Speer#8 manual!
Problem is may of the bullet are different.

 

[alwslate]

The difference in load data between manuals like the Speer #8 and more recent Speer and other more recent manuals is due to pressure testing to a pressure point. It is not due to changes in bullets or powder burn rate changes.

 

[mike campbell]

Alliant Green Dot has changed.

It is not "internet myth."

Many handloaders of shotshells noticed a difference big enough to detect just by shooting. It helped that many had used the same recipe for decades.

Some handloaders resorted to the chronograph to verify their suspicions. I have personally loaded over 1,000 lbs of Green Dot thru the same bushing over a 25+ year timespan. I've chronographed that load a couple of times a year and noted differences concomitant with lot changes of the powder and primer brand....to be expected. After collecting the data for 25 years I felt confident that the more recent results, coinciding with new green cap used on recent 8lb kegs, are statistically significantly different.

A few handloaders went so far as to have loads pressure & velocity tested by independent laboratories which confirmed a "new, hotter Green Dot."

I find the conclusion irrefutable. YMMV.

P.S.

When Alliant changed Red Dot they didn't change the name. They just called it "Now 50% cleaner burning!"

 

[Sevens]

It’s silly for me to comment about how a propellant may or may not have changed over many decades, I have neither the scientific knowledge or insider experience to even comment. I’m just a guy who has been loading and burning powder for 35 years.

To even suggest that hundred year old load data is still valid today across the board is a reckless thing to say, especially if the audience includes new handloaders might take this and run with it.

Modern equipment in far more advanced ballistic laboratories have made pressure testing irrationally more accurate than it was generations ago when some of this data was published.

Here in the year 2024, it’s ludicrous to suggest with the colossal volume of quality data sources available that someone should pull loads from a manual compiled during the Great Depression.

It’s especially ludicrous to choose this particular hill to die on if your only true goal is to try to sound like an authority in an internet forum argument.

 

[cmj8591]

I'd bet that a powder like Bullseye, that has been around for over 100 years, has had it's formulation changed many times over it's lifetime. I'd also bet that the burn rate for Bullseye made in 2024 is very, very close to it's burn rate over it's history. It would be liability suicide to substantially change the burn rate and still call it Bullseye. The differences that we see in data from old manuals to new ones is more about changes in how the data is collected than anything else. The fact that we sometimes see lower maximum charges than we used to is more a reflection of increases in efficiency in components and guns.

 

[rockquarry]

I'm an expert on nothing and certainly don't know the answer here. I've seen this matter surface more than once. Comments and experiences have some worth but we often don't know how much worth. Not really evidence in the strict sense.

None of this matters to the experienced, competent handloader as he knows the right way to safely work up a load. By experienced and competent I make reference to someone who took the time to read and fully understand manuals written and edited by knowledgeable persons rather than those who received a (substandard) handloading education from the Internet.

 

[DWalt]

Note that there is a difference between powders sold to reloaders and powders that are sold to ammunition manufacturers. Powders sold to reloaders are blends from various different powder manufacturing lots, and they are tested to ensure fairly consistent established pressure and MV standards. Propellants sold to ammunition manufacturers may have more lot to lot ballistic variations, but that is of little consequence to them. That is because they will test each lot of powder in their ballistics labs to arrive at a charge weight that meats their ammunition performance requirements.

 

[WR Moore]

I happen to be exploring a new powder for LR precision rifle. I'll mention a phrase about burn rates I ran across whilst consulting different data sources: Burn rates of a given powder may differ depending upon what caliber/pressure level it's being used in.

I mention this because I'm discovering that internal capacities between brass cartridge brands and/or product lines within a brand seem to get really puzzling. I may end up with a cheat card for load data for the different types of brass.

 

[rwsmith]

Powder 'burn rate' charts.....

I happen to be exploring a new powder for LR precision rifle. I'll mention a phrase about burn rates I ran across whilst consulting different data sources: Burn rates of a given powder may differ depending upon what caliber/pressure level it's being used in.

I mention this because I'm discovering that internal capacities between brass cartridge brands and/or product lines within a brand seem to get really puzzling. I may end up with a cheat card for load data for the different types of brass.

Powder burn rate charts are RELATIVE only. Not absolute by any means.

Also, I think that Speer #8 was an anomoly, a mistake, errata. Guns are proofed at like +30% so they weren't going to blow up a strong, modern gun, but the USERS realized that some the loads were too potent and weren't good for our precious firearms. I have a 1970 Sierra reloading manual that has really HOT (read 'hunting') loads. I've ventured into some of the areas that are higher than what is 'normally' published, but I don't care to explore the maximum. Just too raucous.

Also, the varying burn rates is why we don't extrapolate or guesstimate powder loads for different calibers. And if components don't exactly match (mine NEVER do anymore) we drop the load back and start working up again.

Again also, Alliant announced that it was changing the formulation of Unique to burn cleaner, but the loadings have not changed.

 

[cmj8591]

Note that there is a difference between powders sold to reloaders and powders that are sold to ammunition manufacturers. Powders sold to reloaders are blends from various different powder manufacturing lots, and they are tested to ensure fairly consistent established pressure and MV standards. Propellants sold to ammunition manufacturers may have more lot to lot ballistic variations, but that is of little consequence to them. That is because they will test each lot of powder in their ballistics labs to arrive at a charge weight that meats their ammunition performance requirements.

Manufacturers have a completely different way of selecting a powder for any specific load. A manufacturer will start with a velocity and pressure specification for a certain bullet weight and the powder manufacturer will tailor a powder to meet those specifications. They can do that because they have the ability to test as they go and they have the economy of scale to make it economical. Reloaders like us come at it from a completely different direction. We start with a known burn rate and then adjust our loads by the amount of that powder that we use. Although the powder that comes out of a factory round may look like a certain canister powder, the chances are that it's not. The canister powders that we get from the LGS are manufactured to a certain burn rate but there are some variables involved that change the burn rate even from lot to lot of the same powder. Not to mention the variation that occurs in the reloading process itself. If you are using data from a modern loading manual and shooing a modern firearm, that variation is not going to come into play for you from a safety standpoint. They engineer the variation into the data.

 

[dogdoc]

Lot to lot variation in powder is normal. At top loads it makes a difference but unlikely to cause any damage. Most guns have a huge safety margin.

 

[scooter123]

Alliant Green Dot has changed.

It is not "internet myth."

Many handloaders of shotshells noticed a difference big enough to detect just by shooting. It helped that many had used the same recipe for decades.

Some handloaders resorted to the chronograph to verify their suspicions. I have personally loaded over 1,000 lbs of Green Dot thru the same bushing over a 25+ year timespan. I've chronographed that load a couple of times a year and noted differences concomitant with lot changes of the powder and primer brand....to be expected. After collecting the data for 25 years I felt confident that the more recent results, coinciding with new green cap used on recent 8lb kegs, are statistically significantly different.

A few handloaders went so far as to have loads pressure & velocity tested by independent laboratories which confirmed a "new, hotter Green Dot."

I find the conclusion irrefutable. YMMV.

P.S.

When Alliant changed Red Dot they didn't change the name. They just called it "Now 50% cleaner burning!"

It's quite possible for a powder to have the internal ballistics change without any change in the burn rate.

For example if the manufacturing process or formula is changed there can be a corresponding change in the Density. When that happens if you don't change the volume of the powder measure you are using you can see a large change in the produced velocity. It' something that drives me a bit nuts in the Shotgun World. Every time loads are discussed it's "you should use bushing X for that load and bushing Y for this load". Ask them how many grains you get with Bushing X and you get a blank stare. What is really scary about this is that current bushing tables can be 10 or 20 years out of date and I've talked to some folks who are using bushing tables published back in the 1950's because it's what their father used. Folks you need to get a scale so you know the weight of that powder charge because relying on bushing tables is potentially dangerous.

 

[WR Moore]

While Speer #8 is world famous for some of it's loads, they're not the only ones with some data that might raise eyebrows-and possibly some gun parts.

When the 125 gr JHP.357 bullets first came out Hercules put out a fresh data sheet that featured loads for the bullet. The .357 Magnum data startled me. Was really close (same?) to data for the .44 Magnum with 250 gr hard cast lead. I did some comparative volume calculations and decided there just HAD to be a mistake. Hercules came out with a revised data sheet within a month. I kept both for years but they unfortunately disappeared during one of my moves.

 

[mtgianni]

In every manual or guide is a warning to work up a new load every time you change a powder lot number of the same name. It is the single best reason to buy larger containers or multiple bottles.

 

[cmj8591]

It's quite possible for a powder to have the internal ballistics change without any change in the burn rate.

For example if the manufacturing process or formula is changed there can be a corresponding change in the Density. When that happens if you don't change the volume of the powder measure you are using you can see a large change in the produced velocity. It' something that drives me a bit nuts in the Shotgun World. Every time loads are discussed it's "you should use bushing X for that load and bushing Y for this load". Ask them how many grains you get with Bushing X and you get a blank stare. What is really scary about this is that current bushing tables can be 10 or 20 years out of date and I've talked to some folks who are using bushing tables published back in the 1950's because it's what their father used. Folks you need to get a scale so you know the weight of that powder charge because relying on bushing tables is potentially dangerous.

Something as benign as a change in humidity or temperature can change the density of the powder. I used to shoot trap with guys who loaded thousands of rounds without checking to see what their bushing actually was throwing. It's not such a big deal with a shotgun because they operate at a relatively low pressure but when loading near maximum loads for center fire, it's important to know what your measure is actually throwing.

 

[alwslate]

I used to load a lot of mild plinking .38 spl loads with long gone Win 452AA ball powder. When changing from an empty one lb can to a new one I found that to get the same velocity from a new can as the old I might have to adjust the charge weight by 1/10 grain. Not exactly a big deal.

 

[mike campbell]

It's quite possible for a powder to have the internal ballistics change without any change in the burn rate.

For example if the manufacturing process or formula is changed there can be a corresponding change in the Density. When that happens if you don't change the volume of the powder measure you are using you can see a large change in the produced velocity. It' something that drives me a bit nuts in the Shotgun World. Every time loads are discussed it's "you should use bushing X for that load and bushing Y for this load". Ask them how many grains you get with Bushing X and you get a blank stare. What is really scary about this is that current bushing tables can be 10 or 20 years out of date and I've talked to some folks who are using bushing tables published back in the 1950's because it's what their father used. Folks you need to get a scale so you know the weight of that powder charge because relying on bushing tables is potentially dangerous.

None of this post applies to me or the change I referred to.

 

[pistolpete10]

My guess is some of the older recipes were overload back when. I shot 21.5 2400 behind a 245 SWC as my most accurate load in the early 80s, find that load in a current manual or Alliant's website. Either it was an over load, no pressure signs or gun damage from it or the powder was changed. An explanation from the powder company wouldn't hurt.