Surplus 7383 single base powder

[USMC87]

I saw where Jeff Bartlett lists his supply of 7383 as new production single base powder, All the posts I see on here lists 7383 as triple base. If in fact it is single base will it be safer to work up loads with instead of triple base? I want to use it in 243, 308, 270 and 30-06 with jacketed bullets and cast bullets when I get around to it if possible. I'm on the fence with this powder and need a nudge to buy some.

[Maven]

Replied to your PM, USMC87.

[WineMan]

I use it in 30-06 under 200 grain 311284 or 311299 both with GC. With 42 grains of my lot# the M1 cycled perfectly and tossed cases to 1:00. No filler and over the Chrony they move 1,800 fps +/-. I have found that since it is bulkier than IMR 4831 find what LEE dipper holds a safe load of IMR 4831 and dip the 7383. This puts you in the -15% zone recommended by JB. My experience is that it likes to be at full power. I have never gotten into the "Grumpy" compressed powder zone that others have reported.

Dave

[Yodogsandman]

Castpics has some info on it...

http://castpics.net/dpl/index.php/reloaders-reference/surplus-powder-data/196-the-basics-of-7383

http://castpics.net/dpl/index.php/reloaders-reference/surplus-powder-data/198-will-s-7383-data

http://castpics.net/dpl/index.php/reloaders-reference/surplus-powder-data/197-jim-s-7383-data

[Ricochet]

I'll tell you exactly how the "triple base" story got started. Back in the late 1990s-early 2000s my friend Linstrum told me in private E-mails of the great results he was getting with basically full case loads of 7383 in various military cartridges of the .30 caliber to 8mm class. At the time Hi-Tech had a lot of it in 7 lb. jugs for $28, so I got in a good supply. I found it to shoot well in cartridges including .30-06 with 150-180 grain jacketed bullets, .22-250 with 55 & 60 grain jacketed bullets, and later with cast bullets in 8mm Mauser, 7.5mm Swiss (of both the more modern 7.5X55 and the original 7.5X53.5, GP90 sort of load for the old 1889 Swiss rifle), and in the .300 Weatherby Magnum with cast loads. I noticed some quirks about this powder right away. It is about 7/8 the bulk density of other IMR tubular powders, and a noncompressed full case load won't come close to factory load velocities in the .22-250 or .30-06. In trying to push this I loaded some compressed loads and quickly discovered the sharp pressure rise that occurs when you compress it, perhaps due to fractured grains burning faster. You can get away with some compression, but be very cautious. The powder doesn't burn completely at less than full loads in the previously mentioned cartridges (other than the .300 Weatherby where I only tried it for reduced loads, about 2200 FPS with the 200 grain "30 HBC" boolit. In .45-70 so much of it doesn't burn that a somewhat compressed case load with 340 grain boolits was giving me velocities around 1200 FPS and jammed the action of my 1895 Marlin with unburned powder grains. Took a while to get all of that out. This led to the observation that most extruded powders have a gray surface from graphite coating, but when partly burned so the surface is burned off the inside part is usually yellowish or greenish and translucent, but the 7383 grains are jet black through and through. It's got either graphite or carbon black pigment mixed in it. Now to the point of this story. When this stuff is fired, the powder gas has a pungent odor of ammonia! I have never smelled this from any other powders. From rifle loads that burned most of the powder, the ammonia smell is all in the cloud blown out of the muzzle, while the freshly fired cases and bores smell like ordinary smokeless powder. With the abortive .45-70 loads that barely burned the powder, I got ammonia smell on opening the action. So I figured that the ammonia had to be coming from a surface coating that quickly burned off and got blown down the bore to come out first, while the remaining powder burning didn't produce it. Speculating about what could make the ammonia, I thought that the coating of the grains might have nitroguanidine in it, as NQ is said to deflagrate with a lot of sooty smoke and ammonia among the gases, producing no flash in the process. So I thought that could explain why they would try that since this powder was used in the .50 caliber spotter rifle fired before the main barrel of the 106 mm recoilless rifle. If there was such a coating on the grains, that gas would emerge first from the muzzle, reducing muzzle flash, which would reduce exposure to the enemy of where the spotter shot came from before the big bang. I could find absolutely no reference anywhere to nitroguanidine being used as a coating on small arms powders, or in any other way for that matter. It's a well known ingredient in triple base artillery powders, of course. So all of this is pure speculation on my part. Linstrum and I were carrying on lively E-mail discussions about all this. He told me that nitroguanidine on slow heating decomposes with hydrogen cyanide as one of the products. So I scattered grains of 7383 on the surface of the solid lead in my casting pot and watched as it slowly heated. The 7383 grains burned off with much less flame than other IMR powders I've done this way. Each produced a strong puff of very yellow smoke. I don't think I've ever smelled any real bitter almonds, but the smoke had a peculiar smell like stinkbugs that I thought might be the cyanide odor that's described as like bitter almonds. So that encouraged Linstrum and me to think that there likely was nitroguanidine in the coating. Somewhat later Linstrum posted a thread on here about 7383 that's been widely read and is one of the first things that comes up if you Google IMR 7383. In it he strongly warned that one should be very careful with this powder because it is a "high energy triple base powder!" I think that was a jump beyond the evidence I just laid out. The stratification of the ammonia gas in burning in the gun suggests that whatever makes it is in a surface coating only, NOT mixed into the matrix of the powder as would be the case with a triple base powder. So there you have it. I would LOVE to hear from someone with real historical knowledge of how 7383 was produced and its ingredients, or if someone with access to the proper lab facilites would do some qualitative analysis of its ingredients. Linstrum and I could be completely wrong about the nitroguanidine hypothesis. But if so, I want to know what makes the ammonia smell! Meanwhile I still have a good bit of this and will keep right on using it as my mainstay powder for cast boolits and moderate jacketed loads in midsize rifle cartridges and will probably use it again as a reduced load powder in the .300 Weatherby. The ammonia smell bothers some of my neighbors at the range, but not me. :mrgreen:

[NuJudge]

I've gotten strong ammonia smell from 748 shot in .223 ammo in an AR. During a rapid fire sequence it can really be a problem.

[Maven]

Yes, it does emit an ammoniacal odor when fired, but not I wouldn't call it nostril stinging.

Ricochet, Nice to see you're alive and well!

[MT Gianni]

Loved that background Ricochet.

[madsenshooter]

I boost the lot I got from Jeff with a high nitroglyercine flake powder placed 2/3 up the powder column to simulate the flash tube that the spotter round has. It's a flashless powder, another property flashless powders have is less smoke, less than most smokeless powders. There's nitroguanidine there, but it doesn't go off right unless temp and pressure get up to about the same as would come from a 50BMG primer. When it burns clean, with little smoke, there's very little if any, ammonia smell. In 30-06 and 30-40, a magnum primer alone won't get it going right. Overcoming that coating is the peakiness that others have reported. Though different lots also account for some of that. I'm not recommending that anyone else boost it, one could easily double charge the booster and might lose more than their gun. It works with the capacity of cases that I am using, other cartridges might not like it so well. The OP was looking for someone to talk him over the fence, I can't do that. If you do get some, be careful with it is all I can say.

[nekshot]

If you have doubts don't mess with it. If you can use the info here with confidence then its a decent powder. I like it!
Good to hear from you Ricochet, always appreciated your info when you share.

[ez4545]

This is a timely thread. I am dealing with the last items I inherited a couple of years ago when I lost my dad and then my brother. I dealt with everything but the powder because it was fine in my brothers freezer.Now, I need to move the powder before Christmas.

i know for sure there are 4 or five unopened jugs of 7383 and others. My dad kept his powders in my brothers freezer too but he shot mostly bullseye. I know my brother had other unopened jugs too so I'm hoping to find some cool commercial powders too.

I was going to pass a couple of the jugs to a friend but his health is so bad he doesn't leave the house anymore.

He worked with powders in the military and I saw him do things I would never try. He got one of the jugs of 7383 I got in a group buy and he shot most of it up. This is crazy but he has a pedersoli mod 94 muzzle loader. I looked it up on line and it says it has a "magnum" chamber.

What that means I don't know. He had been using 25 grains of 7383 and a.490 round ball. I've seen this gun but I wouldn't try it. I looked at his rifle after he had several trips to the range and I couldn't see any problems. But then again I don't have a magnaflux or xray or anything to really see what was going on with it.

I looked through my brass and it looks like my mausers will be fed a steady diet of 7383 for a long long long time:veryconfu I can't think of a single reason for me to use it in a muzzle loader :shock:

fun stuff

Bill

[Ricochet]

Bill, a 3.4 cc Lee dipper of my 7383 under a 175 gr GC group buy boolit that's similar to the Lee 175 gr works well in all of my 8mm Mausers. With longer, deeper seated boolits like the 8mm Max I have to reduce the charge so it's just close to a capacity load. I think 2.8 cc fits there, it's been a while since I've loaded any of those. I use CCI #34 primers and get pretty clean burning with that. My next experiment in 8mm is going to be paper patching "Fat Thirty" boolits. I've been patching up some of those from .315" to .323" to emulate the original GP90 bullets for the 1889 Swiss rifle, and figure they'd be good for the 8mm as well.

Good to see all of you guys, too!

Hey, Nujudge, it's your boolit I'm patching up for the 7.5X53 Swiss. :smile:

[Ricochet]

Hey, if you search this site for "chemical analysis 7383" you'll quickly find that wiljen had three lots of 7383 analyzed a few years back, when I was absent from the board. Each lot contained 4-6% nitroguanidine. I was right! He talked to a guy who was working at the plant when this stuff was made, and he said they also experimented with nitroguanidine hoping to come up with a powder for 5.56mm ammo that would make it easier to get the velocity they needed without burning up M16 barrels.

[madsenshooter]

Big thing to watch out for is the different lot #s. What I have said about boosting is with the lot Jeff has now. The difference in the lot #s seems to be the percent nitroguanidine. Lot 48000 seems to be the higher percentage. In my Krag a boosted nigh smokeless load with some oversize 190gr match bullets is pretty high pressure, Krag max. 168gr J-words is a more reasonable load. I haven't worked with the load enough to see what effects different temps and such might have on it.

[ez4545]

Thanks Ricochet!
Awesome I have a good selection of lyman and lee molds for my 8mms. I have some new remington brass in 8mm I've been sitting on for a long time. Now that I have a good use for 7383 I might have to talk my son out of some of his 30-06 brass he has a lot and a good bit of it is lake city match once fired.

Thanksgiving lunch is at his house so when I'm done playing with grandsons, I'm going to buy a bunch of that brass to convert it to 8mm. I absolutely love the Lee dippers. I did a test years ago scale vs Lee dipper Volume measure was just as accurate for me as the scale was. I use the dipper a good bit still.

Happy Thanksgiving

[TCLouis]

OK, we have 3 lot numbers of this and several others, why don't we agree to have them listed fastest to slowest and post "Our" lot # when we talk about a load.

When I applied Jeff's 4831- 15% in all the cartridges I load it always matched the powder weights in the manuals for 4064 listed data.

Have yet to extensively try it or do any Chrono work to see where it leads.
My lot is 48001.

I have asked several times and have yet to get an response about how touchy it is as one approaches the max loading.

Is it sensitive at 1 grain, 0.5 grain increase or what in a mid sized case?

[madsenshooter]

I was digging around in some govt paperwork the other day, and found that the primer used for the spotter round was not the standard 50BMG primer. Exactly what the difference was, I can't say, couldn't follow up on the specs. We know there was a flashtube involved. I spotted an odd 30-06 round the other day, the primer looked to be about as large in diameter as a 50BMG primer, I'll see if I can find anymore info on it. TC, in what way to you mean it matches 4064, velocity-wise? I am getting that, but only if boosted and burning clean. I would say that once I get to the no smoke stage, the powder is producing the pressure it was designed to. I've been limiting my testing to jacketed, as it takes a pretty tough alloy to survive the 38,000+psi.

[swheeler]

OK, we have 3 lot numbers of this and several others, why don't we agree to have them listed fastest to slowest and post "Our" lot # when we talk about a load.

When I applied Jeff's 4831- 15% in all the cartridges I load it always matched the 4064 listed data.

Have yet to extensively try it or do any Chrono work.
My lot is 48001.


Louis a bunch of it sold didn't have lot#'s

[Hardcast416taylor]

This is not good for me. I was given a `repackaged` 1 lb. jar of this powder by a friend several years back with no information as to what it is meant for nor what lot # it may be from. Any suggestions as to what calibers I might try this in, or just use it for fertilizer on the flower bed.Robert

[madsenshooter]

It would no doubt be some potent fertilizer. I'd start with Jeff's recommendation of 4831 data minus 15%, starting with a regular primer, next a magnum primer, next increasing the charge until you get something usable. I just noted TC and I have different lots, so his, "it equals 4064" may be right on for his lot. I know TC is a very careful and observant reloader. I have some 150gr FMJBTs loaded with equal weights, 4064 and 7383 (lot 48000) + the kicker charge. I'll try to get out soon to see how that goes. Firing both with a CCI #34 primer, which is meant to fire ball powder. I see parashooter debunked the myth that they have a thicker cup to prevent slamfires, they have an anvil that's not as tall, so not as close to the back of the cup, less sensitive, but a tad more room for priming compound.