IMR 7383, what's it compare to?

[georgeld]

I just got some new surplus 7383 I've never heard of these numbers and can't find it listed in any books.

The Data sheet with it says a full 223 case only makes about 2600fps.
That's too darned slow for this cartridge.

It looks like 4831 to me. But, does anyone have a comparison between these two, or else loading charts for other than .223 and 50BMG with this powder??

Thank you,

[Linstrum]

Hi, georgeld, here is a copy of a post I made back in 2006, although when others post something here take a good look at what they have to say, too, a lot of folks have good useable data. Your best bet is to use the search function for this particular forum because there has already been a lot of threads and space devoted to 7383. To answer your question, it really doesn't resemble any powsder except itself but some generalizations can be made that range from IMR4064 to IMR4350. It is my favorite powder BUT I ALSO RESPECT IT!

~:/+\:~:/+\:~:/+\:~:/+\:~:/+\:~:/+\:~:/+\:~:/+\:~:/+\:

July 4, 2006. The main thing to remember about IMR7383 is that it is a HIGH ENERGY TRIPLE BASE PROPELLANT that goes by different rules of loading density than the normal single and double base propellants that we are normally used to. The third ingredient is nitroguanidine, which supplies both the increased energy content and confers its flashless characteristics. It also makes it very "peaky" when approaching its upper load limits, giving absolutely no warning like the single and double base propellants do that a high pressure excursion is about to happen. This cranky nature is a very unfortunate characteristic of this otherwise quite useful powder. The reason why it is flashless is because it was designed specifically as the propellant for the .50 cal spotter rifle used to aim the 106 mm recoilless rifle. For the purpose of aiming a cannon by "spotting" it is a good idea for the spotting rifle to be flashless to keep the enemy from seeing the muzzle flash and returning fire before the main 106mm cannon has a chance to be fired, which is not flashless. As soon as the 106mm cannon is fired, the crew leaves immediately. I have fired my .30-06 700 ADL at night and instead of getting blinded with a large bright muzzle flash like IMR4895 makes, all I saw was a faint dull red streak emanating from the muzzle. There are at least three lots of IMR7383 that I know of and their characteristic are all different, so what goes for one lot will not work for another and it is a good idea to start off conservatively using IMR4064 loading data at first, then once you get the feel of it you can creep the load up using IMR4350 data BUT STOP AS SOON AS THE POWDER BURNS CLEAN because you are already into the danger zone even though you are not getting any signs that you are there. This lack of approaching high pressure is what makes the stuff so cranky. I use IMR4064 data myself and have had good results. Also, it is not the best cast boolit powder around, although I get reasonable results in my French 36 MAS with the 180-grain .309 cal Lee. Since the French cartridge is practically identical to the 7.65 Argentine/Belgian Mauser, it should work just as well in that rifle/cartridge combination.

I am not trying to discourage using IMR7383 by any means, just be careful. I like the stuff so much that it is my main powder now, I have bought over 100 pounds of it since it became available.

Maven has what I think is really good info for the stuff and I also go by his recommendations since the caliber cartridge it is used in also has a lot to do with its behavior.

[Buckshot]

............I've used it in cases from the 35 Rem to the 6.5 Swede. It did well in the Swede. Was decently accurate in the 35 Rem but posted large ES's. For the price a person can afford to fool around with it if they have a few different cartidges they reload for. Chances are, in at least one t will shine. As Linstrum said, do your workup with a chronograph and pay close attention to pressure signs and indications.

.............Buckshot

[georgeld]

Great, thank you much, appreciate it.

I'm out of 4831 now and still need to load some 7mmags and 300Win's.

Would one of you fellows be kind enough to give me a starting load for these in
175 gr, and 200gr in the 300win?

Would save me a bundle of work since I have only two lbs of it. By the time I work up a load, will be low on powder again.

Who has it and for what price have you found? In Dec or Jan it looks like I can spend $3-500 on supplies again.

Thanks much, IF you don't want to post the loads here, send 'em to my e/mail.

[Ricochet]

Don't have any loads for you in 7mm Rem Mag or .300 Winchester Mag, but if I were doing it I'd follow Linstrum's advice to work up the load as if the stuff was in the range of 4064 or 4320.

I found it in 150 grain .30-06 and 55 or 60 grain .22-250 loads to behave as a slow burning powder much like 4350, in that a full capacity charge weighed about the same and gave about the same velocity as a minimum charge of 4350. I thought it couldn't be overloaded in such medium sized cartridges and got complacent. Works out that way for me in 8mm Mauser with the bullets I've loaded, even with the big old 8mm Maximum bullet that weighs something like 253 grains as I've cast it. (And will only allow a 2.8cc charge in the case.) But I learned since that where larger charges can be accommodated in the case, where the sectional density of the bullet goes up significantly, the powder is crushed by compression, or other factors that raise pressure such as the bullet seated well into the lands come into play, that the pressure rises very suddenly and it definitely CAN be overloaded. I can also attest that 3.7cc of it in a 7.5x55 Swiss under a 200 grain cast bullet crimped and seated against the lands is TOO HOT! The powder was only used in one application, the .50 caliber spotter rifle for the 106mm recoilless rifle, the cartridge for which is a shortened case based on the old .50 BMG. It looks like a 7.62x39 next to a .308 in comparison. 7383 replaced 4831 in that cartridge, giving the same velocity and pressure with charge weights about like you'd expect if the powder burned like 4350 there, but the maximum working pressure of that cartridge was only 38000 PSI. The powder's optimized for this medium pressure range, and its burning rate apparently goes up steeply as the pressure rises above it. You're on your own developing magnum loads for it. I've used it for mild loads with a 200 grain cast bullet at 2200 FPS in the .300 Weatherby; that's 4.3cc of it with a magnum primer. I can't recall exactly how many grains that equates to, I measure volumetrically generally.

7383 is not a normal IMR powder. There is a substance in it that generates ammonia gas on firing, and that substance is in the powder's coating as the ammonia is in the exhaust gas blown out the muzzle and not present in the residual gas in the bore or case normally. Only time I've smelled it left in the gun is when I tried it in the .45-70 and it barely burned the coating off the grains. The substance most likely to be used in a propellant that burns with an ammonia smell is nitroguanidine. It was most likely used in the coating on this stuff to suppress muzzle flash in the spotter rifle. It also makes lots of sooty carbon when it burns, and is made with carbon black all the way through the powder grains unlike other IMR powders which are translucent inside, likely to facilitate steady burning at lower pressures by enhancing absorption of radiant heat. But I've never been able to find any official data on the powder's composition. It's a mystery powder.

It's not "the best powder" in terms of maximum velocity for anything I have. It doesn't directly compare to any other powder, and its burning rate seems to be variable. But it is a very useful powder if its quirks are taken into account and it's loaded carefully. It can give very good accuracy in the right loads, and it is very inexpensive.

There is an old series of messages on the Accurate Reloading board from a fellow who blew up a rifle in, I believe, a 6.5mmx.300 Weatherby Magnum wildcat chambering using 7383. Be careful and reasonable. You're a ballistic experimenter when you use ANY surplus powder. You have to work the same way as the load developers in the books do, with the handicap that you probably don't have pressure measuring equipment. Don't take anyone's word on the Internet, including mine, as gospel for what you can shoot safely. It's up to you.

[Ricochet]

That curious ammonia smell from IMR 7383, BTW, gets me inquiries about what kind of powder I'm burning nearly every time I shoot at the range with others present. "It's old military surplus powder" is sufficient explanation. They all look at me like I'm a little batty, and if anyone's shooting at a bench near me they usually move away.
:mrgreen:

[Jim]

I usually identify it as a "milsurp" powder and let it go at that.

[georgeld]

Thank you, I've printed that info from the link out and will study it once I get back from hunting and have time with no demands to meet.

[wiljen]

I'm out of 4831 now and still need to load some 7mmags and 300Win's.

Would one of you fellows be kind enough to give me a starting load for these in
175 gr, and 200gr in the 300win?



If you are getting ready to stock up on surplus powders, I'd buy some 860 or 872 if available. Both are slower than 7383 and probably a bit better suited to the large magnum cases.

80gr of 860 behind a 175gr in the 7mm Rem gives about 2950 fps.
100gr of 860 behind a 200gr bullet in the 300 Weatherby yields right at 3000 fps

Although both of these can be bested by other powders, I haven't found any of those powders at <$7 a lbs.

I like 7383 in midsized bottleneck cases. I like 860/872 in the large magnum cases. And I hope for the day wc852 returns.

[Ricochet]

I'd think we've pretty much seen the last of WC852.

I got some real complaints from the black rifle shooters down the line last week about the stench of my 7383 muzzle exhaust. Funny thing, though, when I got to shoot one of the black rifles with a suppressor on it, the breech blowback the suppressor induced stung my eyes and smelled of ammonia just like the 7383 I was burning in my Persian Mauser. They were shooting some military surplus .223 ammo.

[Jim]

Makes ya' wonder, don't it, Ric?

[Ricochet]

Yep.

But I can't just say "Yep." and click "Submit Reply." Board says that's too short to post.
:???:

[Ricochet]

80gr of 860 behind a 175gr in the 7mm Rem gives about 2950 fps.
100gr of 860 behind a 200gr bullet in the 300 Weatherby yields right at 3000 fps
I've found that 80 gr. of WC860 under a 175 gr. Hornady spire point gives 2960 FPS average in near freezing weather in my 26" M70, and gives stubborn bolt opening in hot summer weather. A little on the hot side. After discovering the hot weather pressure signs, I've backed down a bit.

100 grains of WC860 in the .300 Weatherby under the 200 grain Speer at just under 3000 FPS in my 24" Vanguard shows no pressure signs, but the powder has to be shaken to fit in my fired, neck sized Remington cases, compresses hard, and has bulged some of my cases just below the shoulder enough to keep the bolt from closing without a little post-loading squeeze in a full length sizing die with the expander ball removed. (Not running the die all the way down, just until the cartridge will chamber easily.) 97 grains is about the max that fits comfortably. That's about what I get with two 3.3cc Lee dippers struck off level with a knife, too, but this Ball powder works well with my RCBS Uniflow measure. The loading manuals usually stop with H870 and AA8700 at 93-95 grains, due to the compression and probably because they use new, full length sized cases with a little less capacity. I don't think enough can be crammed in to cause an overpressure situation with any bullet up to the 220 grainers, at least with the standard Weatherby freebore. YMMV, though.

That missing list of WC Ball powders I had said that the relative burning rates of WC860, WC870 and WC872 are 82, 81 and 80, respectively. Close enough to be basically interchangeable; likely the lot-to-lot variations exceed the differences in the specified burning rates. They're also the coolest burning of the Ball powders, with flame temperatures of 2700-2750K. (From memory.) WC870 was spherical, and the other two are flattened spheroids rolled between calendars to a particular maximum thickness to make the burning rate more uniform, and use a bit more deterrent because of the higher surface to volume ratio of flattened spheroids vs. spheres. I think the WC870 had 5% deterrent, WC860 7%, and WC872 7.5% by weight. (Deterrent is dibutyl phthalate.) 10% nitroglycerin for all of them, as for nearly all of the Ball rifle powders.

[georgeld]

Wow, what a can of worms I opened up asking that simple, short question! love it, thanks guys.

Soon as I get my head out of it and get the inletting, finishing done. Am building a .358 U/M on a 1917 Enfield action that had been filed on, barrel shortened etc. So it wasn't in collecting condition. Just what I like to start some project with. This will make my third '17 sporter. Nice '06, 300 Win and this .358 U/m.

Building it mostly to test my theories about reducing recoil. 26" Douglas, .870" at muzzle. Should be around 11# when finished. Just about right for a kicker imo. Do believe some mercury will be in this one.

After going thru shoulder surgery a few yrs ago am not as tough as I used to be. After going to 200gr in the .300win, and burning 30 two weeks ago from the bench am thinking about putting some mercury in this one too.

Anyone have experience with them? They work as well as claimed? I've never tried one yet, do have one on hand for the 358 though.

Would one of these 800# you mentioned work better all around for the big guns than 4350, 4831, or 870??

Thanks again. Skunked on antelope, truck troubles again opening day. They were run out by the time I got back and roundup time had started too.

[Ricochet]

Would one of these 800# you mentioned work better all around for the big guns than 4350, 4831, or 870??
They're equivalent to H870, which is relabeled surplus WC870.

I've seen no sign of the hard calcium carbonate fouling that H870's known for with the WC860 I've been using, though. I think it was made after the lime fouling problems were noted in M16s in 1964-5 and they reduced the chalk content of the Ball powders. WC870 is older.

I've had my right shoulder reconstructed, but I batter it with the big Magnums.

[james snodgrass]

I,ve been shooting 7383 in a 30/30 contender 14" with 32 grs and a 155 lee gc and get 1600fps. It is a compressed load , It does seem to leave some unburned kernels but not bad. I,ve also shot it in 308 with a 200gr lee gc 36grs for 1600 fps from a 14"barrel. WC 860 I,ve shot in a 458 Lott a case full with any 500 gr cast bullet gets about 1750 fps from a 24" barrel, I,ve also shot it in a 270wsm with a 140 win failsfe I trickled through a very long drop tube and managed to get in 83 grs for 3340 fps without pressure signs that is about a120 fps faster than factory loads.

[felix]

That 7383 powder compares to none that we typically use. It is a triple base powder, and therefore very rare amongst handloaders. ... felix

[Jim]

George,
It's becoming my experience that nobody's on the fence with regard to 7383. Dedicated users swear by it and the non-informed masses swear at it. A few years back, one guy started a campaign to "educate" everyone to the "dangers" of this "unpredictable" propellant.
I've used it, with varying success, in .223, .243, .270, .308, .30-06, .303, 8MM and .45-70. I've been told it can't/couldn't be done, but I even worked up a load with it for my .45 Colt Vaquero and my .45 Colt Henry repro!
I've got a few7 # jugs of it and use it extensively and will continue to do so until I run out and/or can't get anymore.

That's my story an' I'm stickin' to it.

[Ricochet]

That guy who was "educating" us about the "dangers" of "unpredictable" 7383 is the one who blew up a custom 6.5x300 Weatherby wildcat. No info posted as to what sort of load he tried with it. I wouldn't have thought it a promising powder for such an overbore cartridge anyway, other than for reduced loads as I use it for in the .300 Weatherby.

[nelsonted1]

I've used it extensively in all my military calibers. Works very well with jacketed bullets, not so good with cast. The world beater is a max load in my NEF 38-55 and the lee 375 plain base bullet. I'd used 8 grains of Red Dot and Unique at about 950 fps and was very happy until I tried 7383. 7383 ran it up to 1500 or so. I was just amazed at how well it shot!

TED

[nelsonted1]

Got more to add to my 38-55 and 7383.

A friend gave me a bread loaf of bees wax to use in BP revolvers. Since I had a bunch of discs I'd cut out to use between the balls and powder I thought I'd use it in the 38-55. All kind of questions whirled through my head ie too much lube, will the disc stick to some and not others screwing up accuracy. I tried them and like I said, I was amazed at how they shot and every time I looked down the barrel I was happy.

Question was that I never addressed was what would happen if I put those beewax discs in a .308 or 30-06 and full case of 7383.

Anybody tried a beewax disc between powder and bullets in rifle calibers?

[Reload3006]

George,
It's becoming my experience that nobody's on the fence with regard to 7383. Dedicated users swear by it and the non-informed masses swear at it. A few years back, one guy started a campaign to "educate" everyone to the "dangers" of this "unpredictable" propellant.
I've used it, with varying success, in .223, .243, .270, .308, .30-06, .303, 8MM and .45-70. I've been told it can't/couldn't be done, but I even worked up a load with it for my .45 Colt Vaquero and my .45 Colt Henry repro!
I've got a few7 # jugs of it and use it extensively and will continue to do so until I run out and/or can't get anymore.

That's my story an' I'm stickin' to it.

Bringing up an old thread but I just bought a bunch of this from Jeff Bartlett. His site says use 4831 less 15% I am hoping to use this under a 180gr condom in 06 and behind a 100 condom in 243 am I fixn to blow myself up? is this a reasonable powder for the uses I am planning provided I keep on my chorny and start really low. ..... ? advise is very much appreciated. It sounds like a powder one can really love if its respected.

[singleshot]

There's a few more threads around here regarding 7383 that are more recent. That being said, I'd start with starting 4064 or 4350 loads and work up slowly as stated many times. Nobade and I have used it successfully in 7.62x54r and 160-170 grain PP'd boolits. (I got the idea from him and bought a big pile of the stuff.)

[Maven]

Reload3006, Have a long look at these posts: http://www.google.com/cse?cx=001951264366462437169%3Aggn3vg-bjum&ie=UTF-8&q=IMR+7383&sa=Search

[9.3X62AL]

This powder still gives me the fantods. I have some, and it has sat unused since I got it. I might screw up the courage to try it eventually, but not today--or soon.

[rongaudier]

I have been playing with it in my custom 30-06 Savage. Worked up to 51 grains which is about as much as I can fit in the case with 190 SMK. So far I'm pretty happy with the results. I'm not getting the kind of velocities I got with other powders, but I've managed sub 1" 5 shot groups at 200 yards. I got a whole case of it, not sure what I'll do when I run out.

[Artful]

I've managed sub 1" 5 shot groups at 200 yards. I got a whole case of it, not sure what I'll do when I run out.

CRY? I would

[freebullet]

I have been playing with it in my custom 30-06 Savage. Worked up to 51 grains which is about as much as I can fit in the case with 190 SMK. So far I'm pretty happy with the results. I'm not getting the kind of velocities I got with other powders, but I've managed sub 1" 5 shot groups at 200 yards. I got a whole case of it, not sure what I'll do when I run out.

You can buy more. I think most folks read about it and are scared away like a couple of the above posts. I've been tinkering with it little by little with cast. I'd say in most cases smaller than say 308 it's more like black powder. It's one of the few powders that's never sold out through king zeros rein of terror.

[rongaudier]

Yea I think I'll order another case. Hopefully it will be the same lot. I've read as you have I'm sure, that there can be considerable variance lot to lot.

[Linstrum]

Dang! I'll be running out of lead before I'll be running out of powder, something back 15 years ago I never would have thought possible! Darn anti-gun nuts.

There were three lots available when it came on the market about 15 years ago, but I don't recall what the reported variations were. Being a non-canister grade military powder with only one use, it may have quite a spread in burning rate. But for things like .223 Rem/5.56 NATO, .308 Win, and .30-06, I wouldn't worry about it. Just work your loads up, remembering that by the time the powder is burning clean without any "mummies" (charred grains) you are right at the edge of being into dangerous pressure range and need to back off a grain or so, and happy powder burning! The one MAJOR designed-in characteristic no one seems to be aware of is its flashless property. In my post from 8 years ago, I did mention that in my 24" barrel Remington 700 BDL .30-06 that it gives a barely visible dull red-orange streak at night. Without going into a lot of detail, this property may have its advantages for some applications; like for those of us who hunt at the very first light before dawn and are last into camp after sundown, this would have the advantage of not blinding one's self from muzzle flash when follow-up shots are required. When I found out that this powder was flashless I couldn't wait to test it, but testing it after dark where I normally shoot was not a good idea because of upsetting the neighbors by making them wonder who was out there shooting a big loud high powered rifle in the dark. So I went to a lonely remote canyon a few miles from where I live at probably 2 AM in the morning and tested it. It was a warm cloudy moonless night, which was perfect! I selected a road cut embankment as my backstop, turned off my headlights, and fired 4 rounds. I ejected the empties onto the passenger seat, and then went home. As noted, the muzzle flash was just a dull red-orange streak that at 50 or 100 feet would not be easily noticed even when looking directly at it from the side, which for its intended purpose in the .50 caliber range-finding spotter rifle of a 106mm recoilless canon would be perfect!

rl 1,239

[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

[Nobade]

Yep, I have tried duplexing 7383 in my 358 win. It actually worked pretty well, using the 295gr. 358009 NOE bullet. A straight case full of 7383 produced 1900 fps, and duplexing it with .3cc of 10B101 brought it up to 2100 fps with very good accuracy. I was also sort of worried about what would happen, but didn't see any unusual pressure signs in 50 rounds. Not that I would recommend duplexing this powder in anything where it could build significant pressure, but the 300 BLK and the 358 win are practically straight cases so much more forgiving.

-Nobade

[BCB]

I purchased a 7-pound keg of it in 2003 for $27.02. A few of us went together and bought 6 kegs of various powders from Bartlett…

Anyhow, I probably still have 6+ pounds of it left!!!

Having read quite a bit about it on this site, I had mixed reviews—some encouraging and some scary…

So, I have messed with it some in the 223, 30-30, 7-30, and recently the 6.8mm SPC with the NOE 279-124-FP. Bingo—I finally found a use for it…

It worked fairly well with the 311041 in the 30-30 but I found WC-860 or WC-852 were better…

I am shooting 23 grains of it in the 6.8mm and accuracy is as good as I can shoot. I have limited the distance to 250 yards on life-sized steel groundhogs. Smacks them center position most of the time with the proper holdovers…

My keg, LOT # RAD78L 47985, has a burn rate slower than IMR-4064. Yet, it is not predictable to be at or near IMR-4350 all of the time. It is absolutely cartridge specific as to its burn rate…

Still, I guess it does have its uses if the uses are to be conservative expectations. I’m certainly not going to “hotrod” it as even performance engines have parts that go through the block…

Good-luck…BCB

[usbp379]

Bartlett still has this powder in stock and I'm wondering about getting some to try in 6.5 Creedmoor with a 140- or 147gr BTHP. Anyone already tried this application?

[sargenv]

After reading up on the previous older statements.. it's designed for pressure in the range of hot 30-30 ammo (38,000 psi), the 6.5 Creedmoor works at a bunch higher pressure (Max pressure @ 62,000 psi).. so while I have no experience loading this stuff, be careful :)

[Nobade]

Bartlett still has this powder in stock and I'm wondering about getting some to try in 6.5 Creedmoor with a 140- or 147gr BTHP. Anyone already tried this application?Don't bother. Just get some H4350 and you're good to go. You'll never get full velocity before you run into pressure problems.

[usbp379]

Don't bother. Just get some H4350 and you're good to go. You'll never get full velocity before you run into pressure problems.Yeah I was just looking at a couple places that are offering "Black Friday" sales.

The 7383 is still probably a little cheaper per cartridge but it isn't like I'm running a belt fed.

Sent from my SM-G930P using Tapatalk

[Elkins45]

7383 hates cases with skinny necks. The fatter the hole the happier it is. I wouldn’t use it in anything smaller than a 30 caliber because it the pressure curve gets really steep really fast.


My keg, LOT # RAD78L 47985, has a burn rate slower than IMR-4064. Yet, it is not predictable to be at or near IMR-4350 all of the time. It is absolutely cartridge specific as to its burn rate…

Still, I guess it does have its uses if the uses are to be conservative expectations. I’m certainly not going to “hotrod” it as even performance engines have parts that go through the block…

Good-luck…BCB

Much wisdom here IMO.

[Maven]

Well I hate to disagree with you, Elkins45, but my unmarked lot of 7383 works great in my .243Win. and my .30-06, with jacketed, not cast, bullets. Its burning rate is somewhere between IMR 4350 and IMR 4381 (?, i.e., the next slower IMR propellant). Here are the particulars:

Rifle: Ruger #1, 26" bbl., .243Win.

Case: Typically Remington, but also Winchester

Bullet: 85gr. Hornady BTSP or Sierra SP

Powder: IMR 7383; no lot markings on jug

Charge: 40.0gr. - 41.0gr. When ambient temps. are >80 deg. F, the 41.0gr. charge is not recommended due to elevated pressure. These loads -> 2,950 - 3,100 fps from my 26" bbl.

Primer: WLR

Accuracy: 1 m.o.a., often less.


To be sure IMR 7383 is an odd duck, but if you use a chronograph to develop your loads and watch for pressure signs (and heed them!), e.g., difficult extraction, flattened primers, it is quite usable/predictable. It likes higher pressure or rather full case loads, but not compression, which means it burns cleanest with jacketed bullets rather than cast in my experience.

P.S. I also use it in my Type 56 SKS (22.7gr. - 23.0gr.) with a C. E. Harris designed 160gr. gas checked cast bullet and Win. LR mag. primers (~ 1.650fps), but I get unburned powder in the magazine. Extraction is excellent, as is accuracy, btw.

[Nobade]

Similar experience here. Worked up J loads for the 243 in the winter in WV. Moved back to NM, and shot one in the summer. That was dramatic! Won't do that again. My 30-06 loves a case full of the stuff under a RCBS 165 SIL. Shoots lights out with that. But it's got a 1:14 twist barrel and shoots faster than normal '06 rifles. Probably a bit much for 1:10 barrels.

[BCB]

I just took a quick look at some of my records for IMR-7383…

I had chronographed 4 different loads that I stay with using this powder…

My lot, LOT # RAD78L 47985, is slower than IMR-4064…

I used QL to attempt to determine which powder was closer to the actual burn rate of my IMR-7383 and got the following results…

6.8 SPC…~Reloder 17
30-30 Winchester…~CFE-223 or AA-2230
7-30 WATERS…~Reloder 17
308 WINCHESTER…~H-4350

I shot the charge of IMR-7383 over the chronograph and then used QL to determine what burn rate it would be by inputting IMR-4064 numbers into the QL and then adjusted the burning rate factor to get the actual velocity that my chrony recorded.

Example: 30 grains of IMR-7383 gave the same velocity as 30 grains of H4350 in the 308 Winchester. I did try that and the velocities were close enough to say it slower than the IMR-4064 recommended to start with. The other ones were verified except the 30-30 Winchester load as I had no CFE-223 at that time—years ago…

As I previously mentioned, this powder’s burn rate seems to be cartridge based. I did try it in the 270, but I shot one round and I pulled the bullets on the other few—I didn’t like what I heard, the primer, smoke for about 10 feet in front of the barrel, and just a “gut feeling”…

The results above were done with only one weight bullet/boolit per cartridge. Other weights might make much more of a difference in burning rate. Too tedious and time consumer for me to even care about that, due to the limited use I have for it…

Good-luck…BCB

[Moleman-]

Used it in 223, 308, 30-06 and 303 for mainly low cost plinking rounds. Still have two and a half milk jugs of it out of 8.

[Elkins45]

Well I hate to disagree with you, Elkins45, but my unmarked lot of 7383 works great in my .243Win. and my .30-06, with jacketed, not cast, bullets.

SNIP

Charge: 40.0gr. - 41.0gr. When ambient temps. are >80 deg. F, the 41.0gr. charge is not recommended due to elevated pressure. These loads -> 2,950 - 3,100 fps from my 26" bbl.



You make my point for me. If a load is so touchy I have to check the thermometer before I shoot then I want nothing to do with it.

[tarbe]

I am thinking about getting 7383 to use in 450/400 Nitro Express, 470 Nitro Express and 450 Dakota (not full loads in this one...say 40k psi and lower only).

I currently use 85gr of IMR 4831 in the 450/400 with 400gr bullets (Ruger No.1) and 105gr of same in the 470 NE with 500gr (Searcy double rifle).

Any thoughts?

Thought I would drop the above loads about 15% and creep up using the chronograph for a reality check.

Tim

[johnly]

Should work fine for that application. I used it in my 20 bore years ago. 120 grains pushed a .622 diameter 1030gr cast base with authority.
Always wanted to wack a pig with that bullet, but my shoulder gave out before then.

[JonB_in_Glencoe]

There is about 16 good threads about 7383.
I have a couple unopened jugs. About once a year, I go down the rabbit hole hole and read all the 7383 threads.
One of these days, I'm gonna crack the seal on one of those jugs.

[MT Gianni]

Jon check it out in straight wall cartridges or in those with a very slight bottleneck.

[Lloyd Smale]

i know this is an old thread but i looked alot at it in the past. Never actually used it but it sounds alot like aa3100 which is accurate mrp. Ive used that in everything from the 243 to 300 wby with good results. Its pretty much the same burning rate as 4831

[JonB_in_Glencoe]

Jon check it out in straight wall cartridges or in those with a very slight bottleneck.

Mostly, I think about 7383 in my 45-70. But I fear my lightweight Ruger #3 isn't gonna be fun to shoot with the suggested requirements of those who have used it (heavy boolit with a full case of powder). I do have a Pre-64 Win mod 70 in 30-06, that would be better shooting with that formula. But like I said, about once a year I think about it and read these threads, then move on to other, better thoughts.

[MT Gianni]

Yea it is a 90% or greater loading in most cases.

[samari46]

Dug out my copy of load data.
Bullet weight 833 grains
Powder IMR 7383
Powder charge 110 grains
Pressure 38,000 psi
Velocity 1745 fps @ 78 feet from muzzle

Frank

[madsenshooter]

I use it in boosted manner in my K31 with 168gr Tipped Matchkings. I have the slow lot, it was for the tracer round that had the flashtube and a primer even hotter than that standard 50BMG. I put the high nitro 10B101 flakes in the middle of the powder column to somewhat simulate the blast from the flash tube. In order to be flashless and smokeless, the nitroguanidine has to explode before the nitrocellulose beneath starts to burn and no large rifle primer is going to get you there with this lot. The idea being the explosion of the nitroguanidine consumes the oxygen and the nitrocellulose burns without flame. I just moved, don't have the exact recipe at hand. I've worked up to 3.9gr of 10B101. The total charge of 7383 fills the case to the base of the bullet, which I can seat to nearly max magazine length, only the tiniest bit of compression. It's a very accurate load, I've shot hundreds of them. Even used it at Camp Perry. I often get doubles at 200yd with the load.

[JonB_in_Glencoe]

I use it in boosted manner in my K31 with 168gr Tipped Matchkings. I have the slow lot, it was for the tracer round that had the flashtube and a primer even hotter than that standard 50BMG. I put the high nitro 10B101 flakes in the middle of the powder column to somewhat simulate the blast from the flash tube. In order to be flashless and smokeless, the nitroguanidine has to explode before the nitrocellulose beneath starts to burn and no large rifle primer is going to get you there with this lot. The idea being the explosion of the nitroguanidine consumes the oxygen and the nitrocellulose burns without flame. I just moved, don't have the exact recipe at hand. I've worked up to 3.9gr of 10B101. The total charge of 7383 fills the case to the base of the bullet, which I can seat to nearly max magazine length, only the tiniest bit of compression. It's a very accurate load, I've shot hundreds of them. Even used it at Camp Perry. I often get doubles at 200yd with the load.

That sounds like a pretty nice trick. I bet there is some neat homemade tool to do such, like a .250 brass tube with removable piston...or something?

[madsenshooter]

No, just a funnel. Pain in the butt weighing tree charges for each case. One could probably get by with throwing them, but I was making match ammo.

[TCLouis]

I had plans of 6.5X257 or 7-08 with bullets and those plus 30-06 for boolits, but all the weird occurrences kind of dissuaded me from trying it.

Using Bartlett's 4831 - 15% proved to be 4064 data for all that I checked, but reported pressure signs were at various levels other than that made me set it aside.

I need to find bullet/boolit data to let me shoot it up!

[wolfwing]

REAL old thread, but I use it at 15% below H 4831 loads. Using IMR 4831 numbers can goof things up.

[8mmFan]

Just bought some. Seems to be the real deal, black magic, voodoo powder, after reading all of the threads on it here (there are a ton). Sounds like it’s a really, uh, “sensitive” powder?

Anybody currently using this stuff in a 30-06, .270, 7mm-08, 8x57, .243, or 9.3x62? Cast, or jacketed?

8mmFan

[Whole Bunches]

I use it in 303 British with 314299 cast and sized .314 with #2 alloy and 50/50 lube. 34.0 grains, nice accuracy and no leading in 4 303 rifles. 3.08” oal. 1700-1725 fps. All rifles liked it once it hit 1700 fps. Mild pressure with nice rounded primers after firing. Brass separated and neck sized for each rifle. Leaves unburnt powder in bore which doesn’t seem to hurt anything.

I worked up starting at 31 grains, chronographing and shooting for accuracy and point of impact until I hit 34 grains and stopped. Mild recoil at that level which I prefer.

Smell stinks from the ammonia given off. Large stick powder for which I have to weigh each charge. Fantastic powder for my purposes. Amazing that all my 303’s, 1 Martini and 3 SMLE’s, like the same charge.

[MT Gianni]

Dug out my copy of load data.
Bullet weight 833 grains
Powder IMR 7383
Powder charge 110 grains
Pressure 38,000 psi
Velocity 1745 fps @ 78 feet from muzzle

Frank

The key is understanding Franks post that this powder is designed to burn well at or about 38,000 psi. Keep your loads near that and it shouldn't surprise you. How? get some loads that show pressure and velocity of a cartridge near 38K psi and chrono the 7383 to a similar velocity.

[8mmFan]

Thanks for the info, guys. I appreciate it.

8mmFan