Surplus powder loading data?

[swheeler]

The 7383 was used in the 50 cal spotter tracer rounds-M48A1 and M48A2, and in the practice round-T249E2.
IMR-4831 was/is used in the HPT cartridge-T251.
The above information taken from TM 43-0001-27, dated June 1981.

7383 had 3 lots as far as I know. RAD-78L, DUW 48001 and DUW 48000. From chronying loads in 06 and 308, comparing to HP WHites velocities I determined I had DUW48000 lot. All three lots had same warning(I guessed for flash over)

CAUTION Do not underload this powder

[TCLouis]

I think mine is yet another Lot #

[oneokie]

7383 had 3 lots as far as I know. RAD-78L, DUW 48001 and DUW 48000. From chronying loads in 06 and 308, comparing to HP WHites velocities I determined I had DUW48000 lot. All three lots had same warning(I guessed for flash over)

CAUTION Do not underload this powder

My post was in response to Jim's post asking which cartridges use which powder, IMR7383 and IMR 4831.

[shadygrady]

well i am glad the info got here i have over last few years seen it refured to as a 3 base so i finally got involved its a slower type 4831 bulky single base powder my only use of it was with the 50 bmg sabot proj with a 30 cal fmj going about 4300 fps filled the case to top[ press sabot in shot over chrony for a fast reading of 4300

[wiljen]

Something is still amiss. The # you gave (10534781-3) shows the NIIN as assigned 10/12/1977 (way too late to have been in original M48a1 loads) and it being produced by a manufacturer number that is associated with Hercules powders, not IMR. I have given a sample of 2 lots I have here to a friend who works at a large chem plant and he is going to test them for me and we'll have a definitive answer.

[Jim]

Thanks, Will. Lookin' forward to seein' the results of that.

[swheeler]

Wiljen; Getter done, I want to see the results too. I am wondering did anyone get jugs of this with lot numbers on them, seems like Lindstrum had bought up a bunch that didn't have lot numbers, IIRC.

[Rifleman]

Mine didn't have a lot number on it either.

[swheeler]

Mine didn't have a lot number on it either.

same here

[swheeler]

I think mine is yet another Lot #

Would you post the lot number for all of us and who you got the powder from?

[swheeler]

Would you post the lot number for all of us and who you got the powder from?

Guess TC was mistaken about the different lot #, hum?

[Rifleman]

Thanks guys, I know the 7383 has been a bit of a mystery to some, especially if we haven't worked with it much. I think I will stick with 860, 870, or 872 for the big capacity J word stuff, and try 7383 with a 311299 in my '03A3.

[swheeler]

I think mine is yet another Lot #

Thanks for the PM Louis, yes 48001 is one of the lot numbers, am surprised you got some with a lot number on it. Scot

[swheeler]

Something is still amiss. The # you gave (10534781-3) shows the NIIN as assigned 10/12/1977 (way too late to have been in original M48a1 loads) and it being produced by a manufacturer number that is associated with Hercules powders, not IMR. I have given a sample of 2 lots I have here to a friend who works at a large chem plant and he is going to test them for me and we'll have a definitive answer.

Anything yet?

[wiljen]

nope, this was an as can betwixt and between so we wait.

[swheeler]

patiently waiting, thnx

[wiljen]

I found out some interesting facts.

1.) Per the tests I had run neither of us (myself or Shady) was 100% correct. It is a double based propellant, not triple. But the two bases are NitroCellulose and Nitroguanidine. It does not based on the tests contain NitroGlycerin.

2.) One of the chemists at the plant I used to test used to work up the road at Radford Arsenal that made the Rad78L lot and shed some light on it.

3.) The number assigned to it being associated to Hercules and the RAD78L lot are correct in that it was produced at Radford Arsenal in Virginia (now owned by Alliant, then Hercules).

They were experimenting with Nitroguanidine at the time to try and cure some of the problems that plagued early 5.56 ammo. The hope was to maintain pressures while lowering flame temp and improving velocity but it was found to be unsuitable for use due to the added bulk.

All the lots tested for me did contain between 4 and 6% Nitroguanidine along with Nitrocellulose and DiNitrotoluene. Two of the lots also showed trace amounts of Dinitrobenzene which is likely a biproduct of DNT creation.

[swheeler]

Thanks Will

[felix]

You might say it is triple base because of the three energy components. If you include the possible byproduct as an energy producer (I don't know if so), that would be a fourth. Toluene by itself would be a deterrent, and nitro-ing it would at least make it contribute something. Obviously, they were looking for a flatter ignition curve in the 223. How it got into the spotter round business is beyond me because of the gigantic expansion ratio as compared to a 22. Fun and games mixing and matching were prolly required to save time to production of the rounds by whomever was going to do it. ... felix

4831? You got to be kidding me, unless the chemists used that formulation as a starter. 4831 always was a single base, and maybe they did use some toluene inclusion as a deterrent of sorts. Very interesting to say the least. Live and learn. ... felix

[johnnybar]

Here's the question that was sent to a vendor:
I have 22-250, 243w, 6.5x55, 270w, 7mmRM, 300wby, 7.62x39, 7.62x54r and 8x57 calibers. I am guessing that IMR7383 would be more versatile than WC860 or WC870 but, I would like your recommendations on what cartridges can be loaded to factory or near factory velocities with each powder. I have researched the shooting forums a little and read that IMR7383 has a narrow pressure band and can spike suddenly just over it's sweet spot during load developement. In your experience, is this the case?

Does this answer from the vendor sound consistent with you guys experiences with your lots?
"The IMR7383 pretty much duplicates ballistics obtainable with H4831, but with less charge weights. It should do fairly well with all your listed calibers except for the 7.62x39"

I wonder why the spikey question wasn't addressed?