When is Red Dot not Red Dot?

almost 40 years difference in materials and technology

Your loads of 3.5g will be fine. 3.1g under a 158g bullet is a pretty soft load and so long as you have a modern gun, a little over 16k psi isn't going to harm it.

Old data was not as accurate as modern piezo transducers which can pick up much higher peaks than old equipment.

You might be at max with a pocket 38, but a mid range or larger frame 38 will easily handle it.

BTW, the Alliant web site says a Speer 158g LSWC takes 3.4g max Red Dot @ 793 fps.

Been using the 1970s Hornady loads since the 70s

I had posted about this same thing several months ago, I have been loading the 38 SPL with 4.6G of Red Dot under a 158G SWC for over35 years..
Yes its a pretty warm load and chrono's for me at around 1000, fps.
Having loaded and shot thousands of with no real pressure signs or issues, However, I use mine in my SW and DW .357s, These are built to handle the higher pressures.
I don't know what you are planning in using these in but if its an older 38 Spl, it may well be over pressure.
I don't want to preach but you should have really started at a lower charge and checked velocity and pressure signs.
I take all the reloading manuals as a guide only, and usually start pretty close to the start load and then move up in 2/10 grain increments until I reach an accurate load that shows no signs of over pressure. I always use a chrono and personally feel that you should always use one when working up new loads.
As I said earlier I use that 4.6G and love it, but it is too warm for an old 38!
One last point, I have noticed that all the modern manuals have really cut back on charge weights for most powders. Personally I think its a fear of litigation and they have cut way back in the loading tables. Some earlier responses said that they felt it was due to improvements in the powder, I don't buy that as the Red Dot from 30 years ago, chrono's the same as new powder I buy today.
As for your dilemma? if you are going to use it in a modern .357 it will be fine, but in an older 38, I would advise to pull them and use a modern load recommendation, then you can chrono and work up a load that you are comfortable with from a safety and recoil factor.

Alliant's load site lists 3.4gr of Red Dot for 793fps with 158gr lswc, and the +p load is 3.8gr for 846fps. I would try some of the loads that you have loaded, and see how they shoot. If the cases do not stick, it should be safe. Starting loads are 10% less according to Alliant's site.

I'm well aware of the older manuals running hotter charges, and would only use them for a cross reference. Red Dot was reformulated a few years ago to burn cleaner, and is the main reason for the change in max loads. I use the different powder manufacturers/distributor data at their sites as my go to info. It is the most up to date data that you can find.

www.alliantpowder.com

www.hodgdon.com


NCsmitty

Not only is there "drift" in the powder formulation over the decades due to new chemical manufacturing processes, but the methods of measuring chamber pressure have also changed drastically in that same time. If this weren't so, then we'd all be loading with the books from the 1940's.

Use the 1970 book only if you're loading 1970's powder. On the other hand, if you're loading powder you bought last week, then use last week's load data.

I disagree that the Red Dot burn rate has changed over the years.
Because it hasn't.

If it had, there would be a lot of blown up shotguns, from shot-shell reloaders still using the same powder bushings they have used for 50 years.
And there isn't.

What has changed is, better pressure testing methods.
And Alliant & Speer have combined load data after Speer became the property of the same conglomerate, Alliant Techsystems Inc. in 2001.

As such, new Alliant data is only shown with Speer soft swaged lead bullets.
And the pressure & velocity they will stand is what determined the new lower max loads..

I don't know what bullet Hornady shows in your 1979 manual, but it might have been a real cast lead bullet that will take higher pressure & velocity.

rc

They started using piezo-electric pressure sensors instead of copper crushers. The piezo sensors showed spikes that were briefer than the copper crushers could react to. The electronic sensor can graph the pressure curve as a waveform in real time and show spikes that are only milliseconds wide. The copper crusher shows only that the copper was deformed, and a very short high spike won't get picked up reliably.
The spikes they saw were well above safe levels.
Then they reduced Red Dot data to more liability-friendly load levels.
I've got an old Speer #8 which shows some really aggressive loads for Red Dot in small frame guns.

I disagree that the Red Dot burn rate has changed over the years.
Because it hasn't.

Click to expand...

I agree fully...

I have canisters spanning 40+ years, and statistically it's the same stuff...

My oldest Red Dot (and it has more than 2# in it):

Ooo, Ooo, can I play?







IMO the reasons for the difference in data is simple: Lawyers.

Load data changes over time, sometimes up and sometimes down. Occasionally it can be explained by differing components and changes in measurement equipment. The early Hornady books listed data much hotter than the Sierra and Speer manuals of the same time. This has now changed somewhat with the current Hornady data being a bit lower than the current manuals from the other two.

The earliest "free" pamphlet I have from Hercules 1975 (now Alliant) listed 3.6grs of Red Dot behind a 158gr LRN as the max load. There was no +P rating in existence at that time so that was the equivalent of +P in those days. Current loads listed by Alliant and their corporate sister company Speer have increased the loads for Red Dot and Unique over the older Hercules data a bit.

Wise reloaders used the higher end early Hornady data for heavy frame .38's and .357 mags.

I think 5.6 gr Red Dot and a 158 gr .38 Special is too much. You don't even see that much Unique listed for a 158 gr .38 and it is a much slower powder.

Jeff Cooper said 5 gr Red Dot and a 160 gr SWC would "get the .38 up off its knees" but was "contributing to the delinquency of handloaders."

Evan Price says:

"The piezo sensors showed spikes that were briefer than the copper crushers could react to. The electronic sensor can graph the pressure curve as a waveform in real time and show spikes that are only milliseconds wide. The copper crusher shows only that the copper was deformed, and a very short high spike won't get picked up reliably.

Which is true but I disagree with the part about:

"The spikes they saw were well above safe levels."

Those spikes, not apparent until the change from crusher to transducer, had been there all along, ever since any particular powder was introduced. They weren't blowing up guns then and it is hard to see how an oscilloscope trace makes them dangerous.

But I still think 5.6 gr Red Dot is too much.

Oh, yeah, an old Handloader's Digest pointed out that there were nine different grades of Red Dot, numbered 10 - 90.
Only Red Dot 30 was sold retail, the other eight burn rates limited to OEM ammo companies. Wonder if Hornady accidentally got some bulk Red Dot of a slower grade.

1kperday,
Shame on you. That stuff should have been burned up decades ago. My powder might last me a year before I shoot it up. What do you think you have there, wine?

All the "____ Dot" powders were reformulated two years ago with slightly different results. My experience is they are not equivalent.

The newer powders may be less sooty and burn a little cleaner, but if the new Red Dot was not the same burn rate and energy as the old Red Dot they would call it something else. Powder companies know that old powder from 40 years ago is still out there and people are still looking up data for it.

I got into a heated argument a few months ago with some guy on a forum trying to tell me that the new 2400 was hotter than the old 2400 because charge weights were less now than in the 70's.

Guys, I just picked up some Promo, for which Alliant says to use Red dot data. Anybody know if old data or the new Red dot data should be used?

Matt Dillon, when I initially tested Promo using Red Dot load data by weight (as indicated by Alliant), I used current Alliant load data with Lyman #49 and referenced 2004 Alliant load data for 9mm/40S&W/45ACP jacketed/plated/lead loads.

For 45ACP 200 gr SWC, I used current and 2004 load data along with Lyman #49 and settled with 4.0 gr - http://www.thehighroad.org/showthread.php?t=578444

For 9mm 125 gr RN, I used Lyman #49 and 2004 load data and settled with 3.8 - 4.0 gr - http://www.thehighroad.org/showthread.php?p=6480163#post6480163

For 40S&W 155/180 gr FMJ/TCFP, I used 2004 load data - http://www.thehighroad.org/showthread.php?p=6509911#post6509911

Thanks so very much for thes references!

Old or new, all mine runs the same:

All those giant cans of Red Dot have got me drooling. I LOVE Red Dot. I would run 3.5 to 4.2 with 158 gr. Red Dot is a great light-medium load powder.

@jim watson... True a brief milliseconds wide spike would probably be ok and in fact a lot of guns were not blown up...butWe max pressure means do not exceed so the data had to be changed.

So I increased it again and again finally stopping at 4.0 grains, still with no signs of excessive pressure.

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If you ever see over pressure signs in a .38 spl you have gone way beyond the .357 mag level and over 2x the max level.

rsrocket1 said:

1kperday,
Shame on you. That stuff should have been burned up decades ago. My powder might last me a year before I shoot it up. What do you think you have there, wine?

Click to expand...

LOL I've burned up that can of red dot a year ago... and 2 more lbs of the newer stuff since. I'm working on the Herco now.