9mm pressures

[Bird]

Got back from the range after shooting 9mm in my cz75bd for the first time.
I fired 20 rounds each of .357'' dia bullets, coal of 1.118'', mp bullet 124 2r design(actual weight with lube is 129.5g ). Loads were 4.0 unique, and 3.9 of 231. No problems with anything except a little leading in the first 3/8 of barrel.
Later, checking over the 40 fired case, half of them had flattened primers, and half looked the same as other fired brass I picked up at the range for comparison. My 40 cases got mixed up, and I do not know which charge was making more pressure.
Any guesses?

[BMW Rider]

231

[ACC]

231

Not 231. 3.9 grains is the minimum charge weight in 4 different reloading manuals that I have. It is more likely that his cases are just a bit short. Been there done that.

ACC

[BMW Rider]

Not 231. 3.9 grains is the minimum charge weight in 4 different reloading manuals that I have. It is more likely that his cases are just a bit short. Been there done that.

ACC

You're probably right about the flat primers, but the Bird asked which made more pressure. I'm still thinking the faster powder (within 0.1 grains) stuffed in the same small space (same OAL) will make more pressure.

[Ford SD]

Got back from the range after shooting 9mm in my cz75bd for the first time.
I fired 20 rounds each of .357'' dia bullets, coal of 1.118'', mp bullet 124 2r design(actual weight with lube is 129.5g ). Loads were 4.0 unique, and 3.9 of 231. No problems with anything except a little leading in the first 3/8 of barrel.
Later, checking over the 40 fired case, half of them had flattened primers, and half looked the same as other fired brass I picked up at the range for comparison. My 40 cases got mixed up, and I do not know which charge was making more pressure.
Any guesses?

I used Gordons reloading tool 9mm lee 357- 125g cast and oal of 1.118 4.0 unique, and 3.9 of 231 .... its not exactly your load but close

I am Not sure of the results ???? what i See is 231 load is the higher Pressure

What I can not understand is the 231 load = 17000 psi and a velocity of 962fps and ]this should be a mid load and not showing pressure signs are you getting bullet setback and that is increasing pressure ?

If you get bullet setback to app 1.081 you are in the 25k range and getting in to the hot range
if set back (is even shorter) you will be getting even flater primers

[Bird]

The bullets are not setting back. I have dismantled some test rounds, and it took 4 good whacks with an inertia puller to free the bullets. The rear band of the bullets have even been squeezed down 0.001'' to a diameter of 0.356'' with a 50/50+tin alloy mix. I just made an expander plug to fix that.
I took a look at the hornady data site, and they say for a 130 grain berrys bullet of 0.356'' and an oal length of 1.150'' a 3.9g charge of 231 gives 27,600psi.
My bullets are not plated, but I am running 0.001'' larger dia, and 0.032'' shorter loa, which is a lot.
I think I will drop the charge down to 3.6g of 231 and see what happens.
Any suggestions are appreciated, as I am not that familiar with small cases with small charges.

[Dusty Bannister]

CUP and PSI are not the same unit of measurement. What does your Lyman Cast Bullet handbook give for data? That will keep you from an unpleasant surprise a lot easier than loading cast bullets with plated data. The resulting size of your cast bullet at .356 is quite likely why you are having a bit of leading issue. Good that you can resolve that issue.

[Bird]

Dusty,
My Lyman 45th does not give pressures, or loads for 231, but I should be well in the safe zone with Unique.

[Dusty Bannister]

My Lyman 47th edition is 30 years old. Your data source is even older than that and due to manufacturing changes by the powder makers may be unreliable with newer production powders.

[racepres]

My Lyman 47th edition is 30 years old. Your data source is even older than that and due to manufacturing changes by the powder makers may be unreliable with newer production powders.

The only answer here I object to.
No mfg of powder would make such a change. More margin?? Maybe. So, perhaps, less pressure/grain. But not much. Less than lot to lot Im betting! $0.03

[Pirate69]

For what it's worth, using QuickLoad, a 129.5 grain bullet, 1.118 COAL, and a 4.6" barrel. 4.0 grains of Unique gave 17,132 psi and 941 fps. 3.9 grains of 231 gave 20,908 psi and 964 fps.

[Dusty Bannister]

The only answer here I object to.
No mfg of powder would make such a change. More margin?? Maybe. So, perhaps, less pressure/grain. But not much. Less than lot to lot Im betting! $0.03

This is a link to an article that discusses reformulation of several powders. Toward the end, it talks about 2400 being close but not the same after reformulation. Many reloaders caution against the use of out of date data. My comments are only a concern for safety of the individual reloading with old data and perhaps new powder.

https://gundigest.com/gear-ammo/relo...still-relevant

[Larry Gibson]

I've pressure tested side by side comparisons of Hercules 2400 and Alliant 2400 in the 357 and 44 magnums. Given the same equal loads loaded at the same time and tested back to back other than normal test to test and lot to lot variations I've not found any measurable difference between them.

The differences in old data and new data is simply a product of much better psi measurement using transducers than with the older CUP method. Also, the adoption of SAAMI standards as the "rule" in numerous court lawsuits has dropped the "max load" data in numerous cartridges.

[TD1886]

I've pressure tested side by side comparisons of Hercules 2400 and Alliant 2400 in the 357 and 44 magnums. Given the same equal loads loaded at the same time and tested back to back other than normal test to test and lot to lot variations I've not found any measurable difference between them.

The differences in old data and new data is simply a product of much better psi measurement using transducers than with the older CUP method. Also, the adoption of SAAMI standards as the "rule" in numerous court lawsuits has dropped the "max load" data in numerous cartridges.

Recently I bought a whole can of the old Hercules Unique. I also have a new can of the current Alliant Unique. Using the same gun, same bullet, same load (volume measured) shooting over the chrono showed the old stuff to be much more potent. There was quite a difference in the velocity with the older Unique being hotter. Grant you this is not quite the testing you have done, but the chrono isn't going to lie. I attribute it to maybe the old Unique seem much more dry then the new Unique. When weighing the volume measured Unique the newer one is heavier. Do you think that is possible if older powder being more dry burns differently toward the fast end say like dry leaves burn better then wet ones?

[barnetmill]

Quote Originally Posted by Larry Gibson View Post
I've pressure tested side by side comparisons of Hercules 2400 and Alliant 2400 in the 357 and 44 magnums. Given the same equal loads loaded at the same time and tested back to back other than normal test to test and lot to lot variations I've not found any measurable difference between them.

The differences in old data and new data is simply a product of much better psi measurement using transducers than with the older CUP method. Also, the adoption of SAAMI standards as the "rule" in numerous court lawsuits has dropped the "max load" data in numerous cartridges.

Recently I bought a whole can of the old Hercules Unique. I also have a new can of the current Alliant Unique. Using the same gun, same bullet, same load (volume measured) shooting over the chrono showed the old stuff to be much more potent. There was quite a difference in the velocity with the older Unique being hotter. Grant you this is not quite the testing you have done, but the chrono isn't going to lie. I attribute it to maybe the old Unique seem much more dry then the new Unique. When weighing the volume measured Unique the newer one is heavier. Do you think that is possible if older powder being more dry burns differently toward the fast end say like dry leaves burn better then wet ones?

I imagine you would have to duplicate Larry Gibson's loads exactly and see what you results are. I believe the original Unique is a double based powder: goggle factoid says-Unique is a double-based powder composed of 20 percent nitroglycerine and nitrocellulose. We or at least I do not know what was done. To be safe when using data for the older powder I would stay at least 10% short of the modern published max loads.
If they changed the formulation the nitrocellulose formulation might make a difference depending how it is loaded. Also older powder can deteriorate leading to unpredictable changes in performance.

I wonder if the new formulation burns any cleaner leaving less residue behind compared to older batches.

[justindad]

Listen to Dusty.

[TD1886]

Quote Originally Posted by Larry Gibson View Post
I've pressure tested side by side comparisons of Hercules 2400 and Alliant 2400 in the 357 and 44 magnums. Given the same equal loads loaded at the same time and tested back to back other than normal test to test and lot to lot variations I've not found any measurable difference between them.

The differences in old data and new data is simply a product of much better psi measurement using transducers than with the older CUP method. Also, the adoption of SAAMI standards as the "rule" in numerous court lawsuits has dropped the "max load" data in numerous cartridges.

I imagine you would have to duplicate Larry Gibson's loads exactly and see what you results are. I believe the original Unique is a double based powder: goggle factoid says-Unique is a double-based powder composed of 20 percent nitroglycerine and nitrocellulose. We or at least I do not know what was done. To be safe when using data for the older powder I would stay at least 10% short of the modern published max loads.
If they changed the formulation the nitrocellulose formulation might make a difference depending how it is loaded. Also older powder can deteriorate leading to unpredictable changes in performance.

I wonder if the new formulation burns any cleaner leaving less residue behind compared to older batches.

Alliant claims it's cleaner. They said they cleaned up some of their powders. I take that to mean shotgun/pistol powders.

[Larry Gibson]

Recently I bought a whole can of the old Hercules Unique. I also have a new can of the current Alliant Unique. Using the same gun, same bullet, same load (volume measured) shooting over the chrono showed the old stuff to be much more potent. There was quite a difference in the velocity with the older Unique being hotter. Grant you this is not quite the testing you have done, but the chrono isn't going to lie. I attribute it to maybe the old Unique seem much more dry then the new Unique. When weighing the volume measured Unique the newer one is heavier. Do you think that is possible if older powder being more dry burns differently toward the fast end say like dry leaves burn better then wet ones?

You might try that again using weighed charges instead of "by volume". Different lots of the same powder can have different densities.

As an example; my powder thrower set to throw 22 gr of Hercules 2400 will throw 22.8 gr of Alliant 2400. Thus loading "by volume" in the 44 Magnum under a 429421 the Alliant 2400 at 22.8 gr would, no doubt, give higher psi and higher velocity than the 22 gr of Hercules 2400.

[Larry Gibson]

Alliant claims it's cleaner. They said they cleaned up some of their powders. I take that to mean shotgun/pistol powders.

Yes, cleaner, but not different in performance.

[TD1886]

You might try that again using weighed charges instead of "by volume". Different lots of the same powder can have different densities.

As an example; my powder thrower set to throw 22 gr of Hercules 2400 will throw 22.8 gr of Alliant 2400. Thus loading "by volume" in the 44 Magnum under a 429421 the Alliant 2400 at 22.8 gr would, no doubt, give higher psi and higher velocity than the 22 gr of Hercules 2400.

I'll go ahead and try that.