Data chart for IMR 7383

[Jim]

I know this horse has been beaten to death for years. I just came from Castpics and noticed there's no data posted on this powder.

Would y'all be interested in submitting established load data and compiling a chart?

7383 is still out there and is still available. I've got some data, but I know others have loads I don't.

I admit it is a very tricky powder and things can go south quickly if it's over charged. However, if it's used with a good starting reference point, it can produce some decent shooting.

What say the court?

[felix]

It is good, Jim. Speed can range from 4064 to about 4350, depending on bore size in particular. Best used in case full allotments as usual, which is 38 grains in 308, 41 grains in 8mm Mauser. Maven has used it in 243 with some reasonable success as well, and I think he was using condoms to build the required pressure to burn the stuff cleanly. ... felix

I do think someone researched the formulation of this powder to being of triple base design. Therefore, I would NOT jump start a load using a faster normal powder with this powder. The reason being the burn-at- pressure balance will be upset and very well make the whole power composition loose its normally designed progressive curve and go bananas. ... felix

[Jim]

Felix, I'll admit I wouldn't make a pimple on your back side for what I know.[smilie=l:

However, I've loaded this stuff in rifle calibers from .223 all the way up to .45-70. It took me a long time, but I found loads for several calibers and several boolits in each. I even worked up a load for .45 Colt, if you can believe that.

I was just thinking if each member that has successfully developed data submit their records, maybe we could establish a chart, of sorts, for others to refer to.

As for a write up, well, that's been done a thousand times over.

[felix]

That is OK by me, Jim. You can include both of those loads contributed by me above. They will work for any medium thru heavy boolit in the two bore sizes. Adding more powder in bigger cases would be OK as far as the powder alone is concerned in those two bore sizes. ... felix

[Jim]

I sent a list to Wiljen. He said he may add some of his own to it and publish it on Castpics.

[TCLouis]

when I read that it gets pressury fast towards max loads I sit back and did nothing.

Fast as in 0.1 grain increments, 0.5 grain, 1.0 grain ? ? ?

Compiling a chart would be very appreciated by me.

When I applied the percent reduction mentioned by Bartlett, it ended up matching 4064 in every cartridge/bullet combo I was interested in.

[MT Gianni]

Please include lot numbers when submitting loads. They seemed to vary a lot.

[hicard]

I've used 40 grs with a 245 gr bullet in a 358 Winchester and 45 grs in a 35 Whelen with good results.

[Ben]

I use 40 grs. of IMR - 7383 in commercial .308 Win cases formed into 358 Win. with the Lyman 358318 HP, weighing 262 grs. with lube and g/c.

Shoots great.

You have to " settle " the powder a bit to get the bullet seated without compression. I've always read that compressing IMR - 7383 isn't good, so ..........40 grs. is as far as I've taken things.

Ben

[wiljen]

Sometimes very mild compression is acceptable, but not more than that. My finding is as soon as it burns clean, quit upping the charges. At lower pressure than it likes, you get unburnt garbage. The minute you don't get that garbage, you have hit the sweet spot and any further increase only serves to get you in trouble.

[Ben]

wiljen

Yes, you're " on target " with everything that you're saying. I'm in full agreement with you.

Ben

[sundog]

30-06 / 168 SMK or Hdy BTHP / 50.0 gr of IMR 7383 / 2395 fps (chrono'd) and deadly accurate at 200 yards. SD in single digits and ES in the teens.

powder needs to be 'settled' (tap the case several times) just a little so it will not compress.

In the several rifles in which I have used this load little or no copper fouling was found, even after 80 plus rounds for high power. What I did get though was the first several patches coming out extremely black. This powder leaves a different kind of residue then 4895/4064.

[MT Gianni]

I have a lot of notes by Roger Bartsche from Accurate reloading about '03-04. They are not mine and I have not been at that sight often enough to know if he is still around. They could go on cast-pics but it is a collection of data complied by someoneelse. I don't know how the intellectaul properties run with that.

[Jim]

Wiljen and Sundog, obviously, like me, have shot a lot of this powder. Both know what they're talking about.
As for Roger, several years ago, he went on a rant about how dangerous this powder is. He even stated that he would like to see it outlawed.
Like Wiljen and Sundog, I've been burning and experimenting with it for years.
I have about 45 lbs on hand. That oughta' last me a coupla' more weeks.:roll:

[Maven]

MT Gianni, Roger and I corresponded with each other about IMR 7383 on the AR Forum years ago, mostly because of the lack of [reloading] data provided by its milsurp distributors. I know he wrote to them complaining of that and the liability issue it posed. However, once the AR Forum became a subscription only website, I stopped posting there and have since lost touch with Roger. Be that as it may, here is some loading data for milsurp 7383 (no longer have the lot no.):

.243Win.: 7383 isn't a candidate for CB loads in this cartridge. However, it works extremely well with Hornady 87gr. BTSP's and 85gr. Sierra SP's. If you're not sure of the "speed" of your lot of 7383, start with Lyman et al., starting loading data for IMR 4064 or H 380. Chronograph these if possible. Actually, it's imperative to do so. I did and found that my 7383 was closer to IMR 4350 and used that data as a basis for load development with those 2 j-word bullets. 39.5 -41.5gr. worked perfectly: At least 3,000fps and better than m.o.a. accuracy from my Ruger #1. In warmer weather, cut back to 40.5gr. as 7383 is sensitive to high[er] ambient temperatures.

.30-06: Using 7383 as IMR 4350 with 125gr. Sierra SP's, I chronographed 55gr. IMR 4350 against 55gr. IMR 7383. The former -> a mean vel. of 2,545fps +-23fps, whereas the latter -> 2,697fps +-22fps. I never tried IMR 7383 with CB's in this cartridge. Accuracy, btw was outstanding.

7.5 x 55mm Swiss (K-31): My friend Vly tried 7383 in his K-31's, but we had only a small no. of chronographed loads to work with. Some time later I decided to try 38.5gr. 7383 with Ly. #311466 (sized to .309" and seated to the rifling). Mean vel. (n = 20) was 1,967fps +-21fps. Accuracy was as good with this powder and CB as it has always been. In short, you can adjust this powder charge down to 37gr. or up to ~40gr. if using different weight CB's.

8 x 57mm Mau.: I tested Hornady, Sierra, and Speer 150gr. SP bullets with 50gr. 7383 (heavily compressed!) While accuracy and velocity were excellent, I DON"T RECOMMEND that charge. Mean velocity was 2,449fps +-17fps, which is essentially the same as I've obtained using Ken Waters' "pet load" of 48gr. IMR 4064. IMR 7383, however, IS quite user friendly with heavy (195gr. - 205gr.) CB's in this cartridge. 38-40gr. works quite well for me.

[Jim]

Thanks, Maven! that's good data.
Y'know, I forgot to credit you with your knowledge of this powder. Do forgive me!

[Jim]

Thanks, Maven! that's good data.
Y'know, I forgot to credit you with your knowledge of this powder. Do forgive me!

[Maven]

Jim, No offense taken/not a problem at all!

[rongaudier]

Sometimes very mild compression is acceptable, but not more than that. My finding is as soon as it burns clean, quit upping the charges. At lower pressure than it likes, you get unburnt garbage. The minute you don't get that garbage, you have hit the sweet spot and any further increase only serves to get you in trouble.
This is interesting. I ordered a case (42 pounds) of 7383 to use in my 30-06. Today I fired some of my cast bullets (powder coated and gas checked) over 40-43 grains and 1980-2050 FPS. Plenty of unburned powder on my cleaning patch after each shot. I'm thinking of bumping the load up to 46-47 grains and see what happens. I'm looking for that "sweet spot" you are talking about.

[Yodogsandman]

[smilie=b: Please be careful. Use good safe loading techniques like working up slowly.

[rongaudier]

[smilie=b: Please be careful. Use good safe loading techniques like working up slowly.
I hear ya, but I'm beginning to think the 7383 is one of those powders that are too bulky to overload (uncompressed) enough to blow up the gun. I have heard it can be "peaky" and that compressed loads are a no no. But from what I've been reading as long as I stay under 50 (can't fit more than that anyway) I should not have problems.

[JohnH]

This is interesting. I ordered a case (42 pounds) of 7383 to use in my 30-06. Today I fired some of my cast bullets (powder coated and gas checked) over 40-43 grains and 1980-2050 FPS. Plenty of unburned powder on my cleaning patch after each shot. I'm thinking of bumping the load up to 46-47 grains and see what happens. I'm looking for that "sweet spot" you are talking about. I'm shooting 49 grains of 7383 of an unknown lot number (bought this jug at least 7 years ago) in a 30-06 with a Sierra 150 Game King and am getting 2600 FPS. It is accurate, just at the clean burn stage.

[rongaudier]

I've got a box of SMK 190s I'm thinking of trying over 48 (if it will fit). I've been using AA2700 and RL22, but am looking for a more cost effective alternative. My 42 pounds of 7383 is all from the same lot, so theoretically, once I get it dialed in I'll be good to go for awhile. Thanks for the info.

[ballistim]

I have an OLD lot bought from Pat's & found it worked great in midsize cartridges, especially my 30-06. I found that using the same volume-not weight of IMR4350 loads listed worked out very well & were accurate. I'm pretty sure that what is available now from Jeff Bartlett is a different burn rate but am intending to pick up some to try it out.

[ballistim]

I'm shooting 49 grains of 7383 of an unknown lot number (bought this jug at least 7 years ago) in a 30-06 with a Sierra 150 Game King and am getting 2600 FPS. It is accurate, just at the clean burn stage.

http://tapatalk.imageshack.com/v2/15/01/06/0d7f674fdbce603387bb6a292b2be11a.jpg

I shot this coyote at 265 yards with the above mentioned bullet & 46.5gr. 7383 in my pre-64 M70 '06 several years ago. I aimed at the top of his back above the shoulder & it dropped right into the kill zone and he went about 10 yards & dropped. Groups with this load shoot at less than 1" at 100yds., have often had 5 shot groups less than 1/2". Most accurate load in this rifle hands down, and friends stopped looking down on surplus powder after seeing this in person.

[madsenshooter]

I have been using Jeff's lot #48000 in 30-40 and 30-06 using magnum primers. A case filled to the base of a 203gr spitzer, no compression, in the Krag, left me a lot of unburned powder & black smoke. So I put 3.5gr of high nitroglycerine powder that burns at Blue Dot rate under the 7383, reduced the 7383 the same amount and tried again. Unburnt powder went away and the smoke out the muzzle was light gray. I've shot 168gr match bullets out of my 06 that were loaded in the same manner. The holes in the target were very black on the edges, may need a tad more booster in 06.

Here's what a lot of folks are missing. Nitroguanidine is an explosive. It has to explode and not burn in order for the flashless properties to be brought forth. The nitroguanidine explodes and the gases produced by that explosion keep the nitrocellulose from burning with a flame.

It has to reach a certain temperature before that explosion occurs. Around 500F. You can't get there with a LRM primer! If it goes at a lower temp there is some difference in the gases produced. I'm waiting on a copy of the full article on researchgate so I can be more exact in what I'm saying concerning that.

I've also loaded a few rounds in both 30-40 and 30-06 with the kicker near the middle of the case. That ought to come close to duplicating the flashtube found on the 50cal spotter round, without the necessity of the tube. But it's winter and the rounds are just sitting here looking at me.

It isn't a powder for Joe Average to play with, especially not with jacketed bullets in an old rough throated milsurp rifle. With it's slow burning nature, and a nitroguanidine explosion waiting to happen.... that's an invitation for SEE. Some of what I've said above isn't going to be the same for all lot #s, I think the percentage of nitroguanidine varies. Reason for no compression is the fact that the nitroguanidine coating is fragile. Compression breaks the coating, allowing the nitrocellulose to start burning with a flame. Then the temp gets up to and above nitroguanidine's explosion point, but not until pressure has already started to rise. Quick peak when the nitroguanidine does go off.

I should also mention that I contacted a fellow on another board who got some in country experience cleaning the spotting rifle the round was used in. He didn't recall any black fouling.

[rongaudier]

Latest trip to the range 47 grains of 7383 Under a 190SMK = 2300 FPS (+/-) from my 30" barrel custom Savage 30-06. Shot consistent under 1 MOA from 200 yards prone on bipod. At that loading, still a little dirty, but NO unburned powder. Now this isn't the most accurate or efficient load I've ever shot from this rifle (58gr RL22 and 210VLD@ 2800FPS Groups<1/2MOA), but I'm quite contented to use this as a practice round and will try it out next in my 03A3 and Garand. Unfortunately, I don't have conclusive data on the cast boolit load yet as I had chambering issues with it today. For some reason I did not have them seated deep enough DOH! BTW, 47GR 7383 filled the case up to just above the bottom of the shoulder. Probably not possible to fit much more in a 30-06 case without compressing (which is supposedly a no-no). I saw absolutely zero signs of over pressure.127559

[Lloyd Smale]

cool thread. At least the first page anyway. Some old timers that have left and passed that used to be friends. there knowledge is still here though

[wmitty]

Yep, we have been diminished.

[JonB_in_Glencoe]

I have been using Jeff's lot #48000 in 30-40 and 30-06 using magnum primers. A case filled to the base of a 203gr spitzer, no compression, in the Krag, left me a lot of unburned powder & black smoke. So I put 3.5gr of high nitroglycerine powder that burns at Blue Dot rate under the 7383, reduced the 7383 the same amount and tried again. Unburnt powder went away and the smoke out the muzzle was light gray. I've shot 168gr match bullets out of my 06 that were loaded in the same manner. The holes in the target were very black on the edges, may need a tad more booster in 06.

Here's what a lot of folks are missing. Nitroguanidine is an explosive. It has to explode and not burn in order for the flashless properties to be brought forth. The nitroguanidine explodes and the gases produced by that explosion keep the nitrocellulose from burning with a flame.

It has to reach a certain temperature before that explosion occurs. Around 500F. You can't get there with a LRM primer! If it goes at a lower temp there is some difference in the gases produced. I'm waiting on a copy of the full article on researchgate so I can be more exact in what I'm saying concerning that.

I've also loaded a few rounds in both 30-40 and 30-06 with the kicker near the middle of the case. That ought to come close to duplicating the flashtube found on the 50cal spotter round, without the necessity of the tube. But it's winter and the rounds are just sitting here looking at me.

It isn't a powder for Joe Average to play with, especially not with jacketed bullets in an old rough throated milsurp rifle. With it's slow burning nature, and a nitroguanidine explosion waiting to happen.... that's an invitation for SEE. Some of what I've said above isn't going to be the same for all lot #s, I think the percentage of nitroguanidine varies. Reason for no compression is the fact that the nitroguanidine coating is fragile. Compression breaks the coating, allowing the nitrocellulose to start burning with a flame. Then the temp gets up to and above nitroguanidine's explosion point, but not until pressure has already started to rise. Quick peak when the nitroguanidine does go off.

I should also mention that I contacted a fellow on another board who got some in country experience cleaning the spotting rifle the round was used in. He didn't recall any black fouling.
Have you shot those loads yet ? (with the kicker in the middle of the case).
Also, would you consider that load with a cast boolit, like the NOE 311299, which is around the 200gr, depending on alloy.

[Patricklaw]

Have you shot those loads yet ? (with the kicker in the middle of the case).
Also, would you consider that load with a cast boolit, like the NOE 311299, which is around the 200gr, depending on alloy.

Ditto this question. Any updates?

[PewProfessional89]

I have been experimenting with IMR 7383 to work in my AR-15 chambered in 300 blackout with a pistol length gas system. It doesn't run the gun on it's own... not even at 106% case fill with a lee 230 gr. boolit. So I did some reading and found that people were "duplexing" this powder and wc860 in 45-70 govt. with some good results. So I called Jeff Bartlett and placed an order for a couple jugs of BR-5 (Unique equivalent) and IMR 7383. I started off by trying a case full of 7383, which didn't work, then I added 1 gr of BR-5 to the bottom of the case and reduced the 7383 by 1 gr. and put it on top of the pistol powder before seating the 230 gr boolit. I kept the case fill at around 103%. After some trial and error and shooting several rounds with my butthole puckered really tight, I managed to get 3.2 gr. BR-5 below 9.3 gr of IMR 7383 to run my gun and push the pill out at an average velocity of 1248 fps. with a standard deviation of around 12 fps. More experimenting is needed, but I made a rather rough looking video of my trials and results. The video includes chronograph data.

https://www.youtube.com/watch?v=EdxzWY3_o0g&t=845s

[Rapidrob]

While an old thread, I've been using this powder for many years. With most surplus rifles calibers and larger bore rifle this powder works very well. I have won matches with my loads and had no unburnt powder left in the bore. Accuracy has been impressive.
My favorite loads are 40 grains under a 140 grain SPBT .264 bullet in the 6.5 Swede.
44 grains under a 195 grain SPFB .323 bullet in the 8MM Siamese
Both loads shot to the sight settings.

[tarbe]

I have used 7383 in a handful of cartridges.

My fireform load for .348 AI is 60gr with a 200gr Hornady. Nice mild 2,250 fps, but enough pressure to make the new profile.

I am going to do some experimenting in the 30-30 soon. Looking for a decent plinking load with the 150gr Berrys. Appears 32gr is about where compression will start...so that will establish the maximum.

[tarbe]

30-30 Win
30gr IMR 7383 (Lot 48000)
150gr Berrys plated bullet
Wolf primer
FC case
2.55" OAL
Light Lee factory crimp
20" Marlin
Ave 1,615 fps ES (5 shots) 16fps

Will try to chrono some this weekend from a 26" M94


Tim