Surplus powder loading data?

[WineMan]

This is one of those "my turn" replies. Have a jug of IMR 7383 (Lot 48000 GiBrass). Got it before really reading up on a couple of years ago. After reading it seemed to tedious to play with although I did make up some 200 grain 311284 loads for my M1 Garand and it functioned fine with 42 grains (75% fill) and gave 1,850 fps. Fast forward to today and finding some slow powder is not in the cards. My main squeeze these days is a K31 for silhouette and that is where the slow powder is going (IMR4350 lately). The bullets are J-word pulled M118's and as near as I can see they are Match King 175's due to the hollow points and weight. They have to be deeply seated and I have an OAL of 2.835" for the K31. I did my homework (thanks for all the work everyone!!!!). This is the lot that is supposed to use IMR 4831 data less 15% which would have been 42 grains max. I worked up to 44 grains of this lot of 7383 (80% fill) with the deep seating, the bullet is just on the powder, not compressed though and a CCI 200 LRP. This load ran across the chrono at 2,150 fps, good looking primers and only a couple of unburned kernels in the barrel. My normal load is 47 grains of IMR 4350 with CCI 200's and it makes 2,400 fps. I am already over the recommended maximum load but no sticky extraction or other pressure signs. I am probably at 3.3 cc at this load. I would like a bit more speed but I am not sure it is in the cards at this point.

Dave

[cowboybart]

I have used the RAD-78 and another lot that is unmarked. It has performed well in my 260 Encore but not my 260 AR. It worked well in a friend's 270 WSM.
I originally started loading it by "volume". I would set up my powder measure to throw the desired amount of IMR4831. Remove the 4831 from the powder measure and fill it with the RAD-78. I then started going by weight and would use 15% less than IMR4831.
I haven't crono'd anything but the 260 Encore shoots into 1/2" and has a half dozen antelope to it's credit.

[Tom4570]

Got my shippment of 7383 last week from gibrass lot number 48000 which is said to use imr 4831 data minus 15 %. Now my question is if going to use military brass should I also reduce another 10 to 15%? I'm wanting to load this powder in 308 winchester, 243 winchester, and 7/08 remington. Anyone have any suggestion's? Tom

[200grain]

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.

"Triple-base powders use a solvent-based process similar to the double-base powder process (Meyer 1987; Radford Army Ammunition Plant 1987). Nitrocellulose and nitroglycerine are premixed with additives prior to the addition of a nitroguanidine solvent mixture. The nitroguanidine is incorporated into the overall mass without dissolving in the other materials. The final mixture is then extruded, cut, and dried."
https://archives.fbi.gov/archives/ab...002/mccord.htm
https://www.nrafamily.org/articles/2...s-of-gunpowder

"Double and triple base powders contain nitroglycerin (NG) in addition to [nitrocellulose] NC, and triple base powders also contain nitroguanidine (NGG). The energetic materials facilitate the explosion, where NC is the base charge, NG increases the powder’s energy, and NGG reduces the flame temperature. In addition, NGG regulates the relationship between the powder’s energy and flame temperature[4]"
https://stars.library.ucf.edu/cgi/vi...11&context=etd

"Standard propellants for guns and small rockets, for the most part, are made by a solvent extrusion batch process. Procedures differ somewhat according to whether the product is a single-, double-, or triple-base propellant. A generalized procedure, however, starts with the proper grade of dewatered, alcohol-wet NC. If nitroguanidine is to be added for triple base, half of the required amount is blended with NC at the start. If the product is double or triple base, this blended mixture is wetted with a solution of nitroglycerin–acetone and then is mixed further. In the case of triple base the other half of the nitroguanidine is added along with any other ingredients of the formulation. Sufficient solvent is used to make a colloid that will extrude properly. Single base is made similarly by mixing additives and ether–alcohol solvent with NC. Before extruding, the colloid is pressed and otherwise densified. Extruded strands are sectioned to proper grain length, dried, and coated with graphite."
https://www.sciencedirect.com/topics...nitroguanidine

"To further lower the flame temperature and the stress in the loading chamber and barrel during the ballistic cycle, a certain percentage of nitroguanidine(14) is added to DB formulations. The resulting propellant is called Triple Base [17] (Fig. 4)"
page 377, 3. Double Base Propellant, bottom right hand corner
https://www.ingentaconnect.com/conte...6?crawler=true

"6.3. Muzzle-Flash Regulators - The muzzle-flash is due to a post-combustion of gases, carbon monoxide, and hydrogen, resulting from the combustion in the chamber. The incorporation of compounds able to liberate an important quantity of inert gas during the combustion will avoid this post-combustion. The incorporation of nitroguanidine, the principal constituent of triple base propellant, is able to play this important role."
page 381-382, 6.3. Muzzle-Flash Regulators
https://www.ingentaconnect.com/conte...6?crawler=true

"The triple-base propellant found suitable for our composition contains from 50 to percent nitroguanidine having a specific surface of from about 9,000 to 22,000 sq. cm. per cc., preferably above about 12,000. The nitroguanidine is dispersed in 16 to 23 percent nitrocellulose, which is gelatinized by about 16 to 21 percent nitroglycerin, or other suitable liquid explosive nitric esters such as triethyleneglycol dinitrate, diethyleneglycol dinitrate and butanetriol trinitrate. The dialkylphthala'te plasticizer is present in the composition at a concentration of about 4.5 percent and the diphenylamine stabilizer is present in a concentration of about 1.5%."
https://patents.google.com/patent/US...?q=C06B25%2f18

"Other energetic materials present at military facilities include 2,4-dinitrotoluene (2,4-DNT), 2,6-dinitrotoluene (2,6¬DNT), nitroglycerin (NG), perchlorate, nitrocellulose (NC), nitroguanidine (NQ), and pentaerythritol tetranitrate (PETN). NC, NG, DNT, NQ and perchlorate are used in several different types of artillery, mortar and rocket propellants, in the form of single base (NC/2,4-DNT), double base (NC/NG), triple base (NC/NG/NQ), and composite (ammonium perchlorate containing) propellants (Refs. 59, 2, and 13)."
https://www.epa.gov/sites/production.../epa-8330b.pdf

"Depending on gunpowder's composition (active components), they can be classified as: i) single-base gunpowders, which contain mainly nitrocellulose, ii) double-base gunpowders, which contain nitrocellulose and other explosive substance (nitroglycerin, dinitroethylenglycol or dinitrotoluene), and iii) triplebase gunpowders, which are composed by nitrocellulose and two other explosive substances (nitroglycerin or dinitroethylenglycol [or dinitrotoluene from above] and nitroguanidine)."
https://www.researchgate.net/publica...MAL_PROPERTIES

[alamogunr]

I just discovered this thread because the last poster found it and posted. I'm saving it just in case senility overtakes me and I order some. I'm not a big experimenter so don't need to be fooling with anything that has as much variation as this powder seems to. WC860 is the limit of my experimentation.