Imr7383

[JSH]

I know there is or was a bunch of talk on this powder. If I go with say 4350 data and CB's anything special I should look for. Oh, will be in the 06 or that is the plan.
i bought a jug of this cheap a couple of years ago and figured i might as well start to use it rather than stare at it.
Thanks
Jeff

[Ben]

Your lot and my lot may or may not be the same. I've used IMR 4064 load data. I'm conservative and don't " red line ", I've not had any problems.

I've found it best in bottle neck cases .270 and smaller.

I used IMR 7383 in some 6 mm Rem. loads with a Hornady 85 V-Max, those shot sub 1/2 ".

Ben

[BCB]

JSH,
I have used it in the 30-30 and the 7-30 Waters. I started with IMR 4064 data also. I didn't have any problems. It is actually a very accurate powder in the 30-30 using 311041 bullets shot from a Super 14". Good-luck...BCB

[Ben]

If you're fortunate enough to be shooting a cartridge that is compatable with IMR 7383 , it is wise to stock up on it. Propellant prices and gasoline prices seem to be headed in the same direction.

Ben

[Trailblazer]

I celebrated the 4th by going to the range and setting off explosives. 30 or 40 grains of IMR7383 at a time. I concurrently celebrated our Bill of Rights by exercising my 2nd amendment rights. Great morning at the range!

I tried 30 and 31 grains in the 30-30 with a 165 grain Saeco 311. The 30 grain load had a 5-3/8" pattern at 100. 31 grains reduced the horizontal spread but I still got a vertically strung 4-1/4" group. I used Winchester LR primers. Should I use magnum primers? I had a fair amount of half burned powder in the bore.

Also tried 41 and 42 grains in the 7-08 with 100 grain Sierra hollowpoints. The 42 grain load went into .9" and clocked right at 2700 fps. Very easy shooting load and it burned all the powder. I was surprised that the 7383 worked so well with the light bullet!

[Nobade]

I've been working with it in the .260 Rem, and it's just about perfect for that. It was a little peaky in the .243, good in the 7-08 with heavy bullets, and too slow for the .308.

[Linstrum]

Hi, guys,

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 105 mm recoilless rifle. For the purpose of aiming a cannon by “spotting in” 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 105mm cannon has a chance to be fired, which is not flashless. As soon as the 105mm 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. 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 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. With around 39 grains if IMR7383 it also works well using Hi-Tech’s 140-grain .308 brass tracer jackets in the French and .308 Winchester cartridges. I don’t know if Hi-Tech still has any of the tracer jackets left, they were a real sweet deal for cheap extremely accurate plinkers at 6¢ each.

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.

[Jeffreytooker]

I've been working with it in the .260 Rem, and it's just about perfect for that. It was a little peaky in the .243, good in the 7-08 with heavy bullets, and too slow for the .308.

Our shooters association has a 1000 yd HP match. I have been looking into the 280 Rem with 175 gr Match King bullets as a combination to use for this game. It works out that IMR 4350 is a good powder for this cartridge. Has anyone done any loading of the 280 with 175 gr bullets and IMR 7383?

Jeffrey Tooker
Paynes Creek Ca.

[StarMetal]

Jeff,

If I was serious about winning that 1000 match I'd build me a good rifle in 6.5-06.

Joe

[45 2.1]

Not the 280, but the 7.5x55 with 168 match bullets. A good accurate powder, but needs full loads drop tubed into the case to get good burn.

[Maven]

Here are some loads that I chronographed with jacketed bullets and IMR 7383 for both the .243Win. and .30-06:

.243Win., Ruger #1, 26" bbl. with Hornady 87gr. BTSP. Figures will be Mean vel., Standard Deviation and Extreme Spread, respectively
38gr. -> 2,638; 42; 140

41gr. -> 2.911; 37; 114

42gr. -> 3,066; 26; 85

43gr. -> 3,099; 28; 105. I consider this a MAX. Load! In fact I generally use 40.0 or 40.5gr. 7383 with this bullet or the Sierra 85gr. SP.


.30-06, Mod. 70 Winchester, 22" bbl. with 125gr. Sierra SP (all I had on hand)
55gr. IMR 4350 -> 2,545; 23; 64

55gr. IMR 7383 -> 2,697; 22; 77

Accuracy in each rifle was better than 1 m.o.a. Btw, there are better, though probably not cheaper, powders available for use with cast bullets, e.g., WC 820 and AA 5744.

[Jeffreytooker]

[QUOTE=Maven]Here are some loads that I chronographed with jacketed bullets and IMR 7383 for both the .243Win. and .30-06:

Maven:

Thank you for the reply and the information. Have you run side by side compairisons between 7383 and another powder?

I have a chronograph, Quick Load, 150 gr bullets and IMR 4350, 4064 and 7383. I can start up from mild 4350 and 4064 loads and track them going up. Then I can go back to 7383 and start up the same way.

This leads me to a few questions. First having Quick Load, I can get pressure curves for the loads I am using. When we say 7383 ranges between the boundaries of 4064 and 4350, can we believe that its pressure curve is similar (in shape, function) to 4064 and 4350? They are all IMR stick powder and should be the same base formula with deterrents and other things to control speed. If we have a similar pressure curve we should be able to compare same loads (by powder weight) and resultant velocity of 4350, 4064 and 7383. This should give us an approximate Pmax for the 7383 load. All of this to be done while watching for indications of high pressure.



Jeffrey Tooker
Paynes Creek Ca.

[Maven]

Jeffrey, No, I haven't run side-by-side comparisons of 7383 and other powders with the exception of what I posted yesterday. What I have done is examine chrono. data for IMR 4350 and 7383 in the .243Win. with 85gr. & 87gr. jacketed bullets. In that instance, 7383 was slightly slower than 4350 and you'll find it is less dense (fluffier) as well. Reread Linstrum's post about the complex and somewhat touchy nature of it before you attempt any pressure projections with QL, et al. Also, its burning rate varies by lot, which is to be expected, but also by cartridge size, bullet weight, how the bullet is seated, ambient temperature etc., which is why we treat it with care.

[Jeffreytooker]

[ In that instance, 7383 was slightly slower than 4350 and you'll find it is less dense (fluffier) as well. Reread Linstrum's post about the complex and somewhat touchy nature of it before you attempt any pressure projections with QL, et al.

Maven:

Have reread Lindstrom on 7383 and filed a copy in the folder in which I am keeping my 7383 comp data. I plan to start with 4064 at about 80%. I first have to get my new Chrony up and running. When you used 7383 did you ever get pressure signs? If so what was the first sign you had?

Jeffrey

[Ricochet]

In .22-250 with 55 and 60 grain jacketed bullets, .30-06 with 150, 165 and 168 grain jacketed bullets, and 8x57 with 253 grain cast bullets, the maximum is how much can be squeezed into the case. No pressure signs, and velocities are considerably less than maximum achievable with other powders. The bulk density is something like 7/8 that of most other IMR powders. No side to side comparison from me, but the velocities match closely with published velocities for the same charge weight of 4350 (which is always at the starting end of the 4350 loads for these cartridges, as no more of the 7383 will fit.) In large magnum cases it would be easy to fit in as much by weight as maximum listed loads of 4350, and the results might be very different on that end. I haven't ried it. If I do load any in my 7mm Rem Mag or .300 Weatherby Mag, I'll start on the low end of 4064 and work up slowly and cautiously.

I tried it once in a .45-70 with 340 grain cast bullets. Never again. Velocities were much lower than standard black powder, with a very wide spread, and the action jammed terribly with all of the half-burned powder tubes that fell back out of the barrel.

This powder is different from other IMR powders not only in having a different deterrent coating that produces an ammonia smell when burned in the rifle and a hydrogen cyanide-smelling yellow smoke when slowly heated to ignition in a lead pot (suggesting nitroguanidine in the coating), but the powder grains are black through and through. The nitrocellulose has carbon black mixed in. I think they did that to make it burn better at the modest pressures of the cartridge it was designed for, the .50 caliber spotter round used with the 106mm recoilless rifle. The powder had no other application. (The reason carbon black would aid burning at modest pressures is by absorbing infrared and light from the incandesccent powder gas in the surface layer of the powder grains, rather than letting it penetrate far into or through the normally translucent grains. Then the heating of the surface to ignition temperature is not dependent only on convection heating from contact with the hot gas.) I don't have the load data (which can be found in the back of late editions of Barnes' Cartridges of the World) in front of me, but 7383 replaced 4831 in the second version of that cartridge, in about the same weight ratio as one would see in many cartridges for 4831 and 4350, with identical ballistics, at a maximum pressure of 38,500 PSI. It would appear they wanted a more efficient and clean burning powder, that better filled the case with the lighter charge, and likely used the special coating to minimize muzzle flash.

It is a smoky and sooty powder. I like the smell.

[sundog]

50.0/IMR7383 and a Sie 168 BTHP is 2395 fps with a single digit SD and an ES in the teens. Bullet sits on the charge w/o compression. On paper at 200 I've shot several mid to high 190s/200 with lots of Xs prone with irons for high power with a heavy bbl Mdl 70 in '06. Leaves a very heavy black fouling in the bbl which appears to help reduce copper fouling, but apparently does not affect accuracy even at 80 rounds. sundog

[swheeler]

30/06, 168 bt, 50.0 IMR7383(no lot # provided) RP9.5 pr, FC brass=2380 fps ES 8 5 shots .987 @100 yds
Same load and rifle with a magnum primer(WLRM) velocity increase of 122 fps to 2502 ES 40- use a standard primer
This from 22 in Salvage rifle

[Maven]

Jeffrey, I only got pressure signs in the .243Win., probably because I was using 43gr. [of 7383] on a warm day. Those signs were flattened primers and enough case expansion to require FL rather than neck sizing in a Lee collet die. I.e., the neck sized brass was difficult to chamber. Since I use the .243 for target work, I saw no need to stress the brass or the rifle any longer and dropped the load to 40-41gr. Btw, with a BT bullet, 43gr. will force its way up and out of the case when you try to seat the bullet. Lastly, neither my cases nor my bbl's. were markedly sootier than when I used something like IMR 4064 or IMR 4350.

[swheeler]

JSH; you asked about cast and 7383 in the 30/06, so I will try to keep on the subject. Yes you can use it with cast in the 30/06, I have had my best luck when used in conjuntion with dacron filler and a standard rifle primer, the filler because it ignites very easily and I do not want it to flash over increasing the burn rate dramatically. You have to understand that your lot of 7383 may be of different speed than my lot, so be conservative and work up until you find best accuracy in your gun. Start somewhere around 35 grs and use enough dacron to keep the powder positioned against the flashmhole, this should be about 1 gr, DO NOT pack the filler into a clump, but instead drag it into the case so that it touches the powder and fills the case into the neck so the boolit compresses it when seated. I used a 200 gr -C309/200/r Lee cast of 17 BN alloy(.3105+ 50/50 lube), CCi 200, and FC 210 primers. Most accurate for me was 37.0 grs+ dacron+cci 200+wcc brass=1812 fps ES46, my lot burns clean with this loading, below this there is some trash left in the barrel(but not miuch) and at 35.0 grs group size is double.

I am currently using 7383 and this same boolit in the 30/40 Krag, boolits sized to groove dia and 2000 fps, same thing applied to accuracy- kept improving as the charge increased, it will slay something soon.

Hope this helps with your original question some, sure is easy to get off on another tangent.
Scot

[Jeffreytooker]

<<<The bulk density is something like 7/8 that of most other IMR powders. No side to side comparison from me, but the velocities match closely with published velocities for the same charge weight of 4350 (which is always at the starting end of the 4350 loads for these cartridges, as no more of the 7383 will fit.)>>>

Ricochet:

I did some density compairisons between 7383 and 4350 and your 7/8 number is right on. I actially got a bit over 85%. I ran the numbers from Swheeler against 4350 in Quickload and was within 50 FPS. I assumed 22" barrel length.

Jeffrey

[Jeffreytooker]

Jeffrey, I only got pressure signs in the .243Win., probably because I was using 43gr. [of 7383] on a warm day. Btw, with a BT bullet, 43gr. will force its way up and out of the case when you try to seat the bullet.

Maven:

I am not surprised with either the pressure or the compressed 243 load. I was checking the amount of 7383 I could get in a 7 X 57 case to the base of the neck. 40.5 gr, is to the base of the neck. The 7 X 57 necked down to 243 is the 6MM Rem. I know it has more volume than a 243 Win. You must have had it packed tight.

I have decided when I do my compairisons 40 gr by weight will be the heaviest load. 7 X 57 150PSP with 40 gr of 4064 is 2646 fps 42809 psi. With 40 gr of 4350 is 2449 fps with 31151 psi. The 40 gr of 7383 ought to work out close to the 4350 load. I will be shooting steel plates to 500M so it ought to be a good light load. As long as it rings the plate and knocks off the paint it is good to go.

Jeffrey

[JohnH]

Not sure if this is worth anything to you guys, but I'm using 7383 in a TC Encore 375JDJ rifle (26" tube). I got a chance to clock some of this last weekend and 40 grains drives the Lyman 379449 at 1711 fps and 42 grains drinves the same boolit at 1768 fps. Both loads have an extreeme spread of 40 fps.

[JSH]

Scot, thanks for the input.
John, thanks also, I may know of some one with that same combo that would be interested.
As to the 7383. I think I may give it a go in the 25-06 with FLGC's using 4064 data. Just looking for a fair to good plinking/varmint load so I can shoot this rifle more. I don't have a 25 mold nor do I want one. Swore I would never fool with casting for anything smaller than 30 caliber, then a Swede came along and a mold for it.
Thanks again gents.
BTW doesn't bother me one bit when a thread gets some what sidlined, seems like they always make a full circle.
Jeff

[Jeffreytooker]

Has anyone loaded 7383 in a 7 X 57? I will be shooting iron sights offhand with mine. I will use a Lee dipper. It throws about 39.4 gr. This should be good enough. The speed should be in the 2300+' range which is enough for steel plates. The same dipper was a minimal load in 7.5 X 55. It shot OK.

Jeffrey

[mdatlanta]

I wonder if this stuff would work with the 6.5 Swede and 140gr hunting or target (jacketed) bullets?

How hard is it to remove that black fouling someone metioned in an earlier post?

[Ricochet]

It's just soot. Comes out with normal cleaning, not too much trouble.

[Hammer47]

Jeff......Works wel in my K31 with the cheapie 150 gn flatbase surpluss [.05ea] bullet from Pat. Just bought 2K more of them yesterday. Regards...g

[Jeffreytooker]

Jeff......Works wel in my K31 with the cheapie 150 gn flatbase surpluss [.05ea] bullet from Pat. Just bought 2K more of them yesterday. Regards...g

I am loading my K31's about the same. I am using 147 gr FMJBT surp bullets. I load mine with a Lee dipper. I am at about 39 gr now. I am going to try some at about 43.

I shot my 7 X 57 with 42 gr and a 150 gr bullet. It was a good load. I have not shot it for group much. I do not think I would go any hotter. The powder is right at the base of the neck, and so is the bullet.

Jeffrey

[sundog]

Anyone want to venture a guess on how much 7383 to go with Sierra 150s in 8x57, for a K98 scout carbine? Got gifted 200 bullets a few years back (yeah, feller just gave'm to me), and I figured this would be a good way to use them up in my buddy's K98 that has a 2X scope scout. Nice setup. Bring it up to the shoulder with both eyes open and looking at the target, and the cross just kinda naturally settles over the target. Dandy.

Btw, I've been shooting 7383 in a scoped 03A3 with 168 BTHPs, and it works well, 'very well'.

[Linstrum]

Hi, sundog, since the 8x57JS is fairly close to the .308 Winchester and French 7.5x54 in case capacity, I would use loads for those as a starting point. I use 39 grains IMR7383 with a 136 grain .308 copper jacketed bullet in the French MAS 36, which would probably be okay for the 8x57JS with a 150 grain bullet since the sectional density is probably about the same as the 136 grain bullet. I'd start with maybe 35 grains the first time to see what happens and increase loads by 1/2 grain. Some load combinations with 7383 never do show pressure with a full case, but others can't be filled all the way up before having problems.

In my experience, as soon as a load begins to burn clean is when that load is at the point of having a high pressure excursion, so burning a bit dirty is okay. I don't know how temperature sensitive 7383 is, so loads worked up in cold weather may be too hot in warm weather.


rl649

[Ricochet]

I can't get enough 7383 in an 8x57 under a 175 grain boolit to cause pressure signs. 3.7 cc under a long-seated boolit works fine and gives about 2100 FPS. Seems to me like that's about 41 grains, but I don't weigh it, I dip it.

[sundog]

Thanks, just about what I've been thinking. We'll have a chrono handy, so if we get'er done I'll post the results.

[woody1]

A couple years ago I worked up a 7383 load which I settled on for Hornady 150 RN's in my 270 Winchester. The load is 48 grains of 7383, in RP brass with WLR primers. I seated the bullets to the cannelure giving a cartridge OAL if about 3.215". This load gives me 2660 fps in my Ruger 77 Mark II. As I recall, I worked up from 45 or 46 grains prob'ly a half grain at a time and the velocity progressed normally. I think I went to 49 grains and then dropped back but I'm not sure. The load burns clean and definitely shoots minute of deer to 200 yards in my rifle.

When I sighted the rifle in with this load, I used 3 shot groups with each sight setting and distance. The three shots at 100 were just a fraction under 1". Two groups at 150 were one at just under 2" and the other at 3 1/4" and strung vertically. My 200 yard 3-shot group is under 3". Admittedly 3-shot groups don't prove consistency but this is definitely a minute of deer load and I'm still using it.

Remember, there's several different lots of this powder. Work up carefully.
Regards, Woody

[Linstrum]

Hi, guys,

IMR7383 is pretty close to flashless, which I like for first light and last light situations.

I looked in my notes from years ago when I first got my MAS 36 7.5x54 French boltgun and I found that I was also using the Lee 180 grain gas check .309 with a good clean burn. The lot of powder I had back then was one of the first that Dan at Hi-Tech was selling. I recently bought more 7383 but I haven't worked up any loads with it, yet, it is a different lot than what I got ten years ago.

woody1: Do you recall how close to being full your .270 cases were with 48 grains? I don't own a .270 but I'm curious since I'm trying to determine what the case shape parameters are that lead to either good results or high pressure with 7383. Maven had high pressure in the .243, so that tells me a little; a large case capacity and small bore by comparison leads to pressure, which is no big surprise at all. I would think that the .270 would kind of be in the .243 ballpark as far as the load maxing out before the case is full.

Sundog: When 7383 works, it works darn good, and from what Ricochet posted it would appear that it is a good cast propellant for the 8x57JS since 2100 fps with a full case pushing a 175 grain boolit is not too far out of line. If you have the same lot of powder that Ricochet has then I suspect that you are in good shape with your particular bullet.

Even though it appears that IMR7383 is not a good all-around cast propellant, it does work very well in some applications. It may also be pretty good in .308 Win with a 180 grain cast boolit.


rl653

[Jim]

Hi, guys, ....
woody1: Do you recall how close to being full your .270 cases were with 48 grains? rl653

I loaded some 150 round nose FLGCs with 49 grains a few years back and I had lightly flattened primers. IIRC, the case density was about 98% or so.

[sundog]

I checked one of my 8x57 cases last night. As powder was added, the case was tapped to settle the powder (same as I do to get 50 grains in an '06 case). Loaded to the base of the neck the charge weighs 44 grains. My initial thought for this load, mentioned above, with the Sierra 150s was 40 grains, Linstrum suggested 35. I'm thinking now, even though I'll start low and work up, that even 44 grains with the jacketed 150 is not going to be too much. We'll see.

A shooting buddy has tried 7383 in his .308, and did not get results near as good as his favorite loads.

[Ricochet]

The 3.7cc loads I mentioned were full to the base of the neck or very slightly above with the powder shaken down, and I think you're right, it was about 44 grains. I had to seat my bullets out to the second band to avoid crushing the powder, which you don't want to do with 7383. I'm using the group buy 8mm bullet of maybe 3 years ago, which is similar to the Lee 175 grain but is sort of a semispitzer with a small meplat. That load is safe, but you'll see better accuracy with a bit less. (And you'll see more partially burned powder remaining, it almost burns clean with the full load.)

[felix]

I shoot 41 grains with the RCBS 32Special boolit, Corky. I use a powder thrower, so the scaled weight of this amount allows the powder to vary without getting into the boolit seating compression range. If you can see the beer can with military sights, it's a dead beer can. ... felix

[woody1]

woody1: Do you recall how close to being full your .270 cases were with 48 grains? I don't own a .270 but I'm curious since I'm trying to determine what the case shape parameters are that lead to either good results or high pressure with 7383.
rl653

Close to full but not compressed. I did go to 49 grains as a check and, unlike Jim, didn't see any pressure signs. I backed down to 48 grains as it was the velocity I was looking for and accurate enough for what I wanted. I did not shoot any of the workup loads for accuracy. Regards, Woody

[sundog]

Okay, just punched off a couple of those Sierra 150s with 42.0/7383. Very light recoil, very low flash (it's REALLY dark outside!). Several kernels of powder in the bore. This load is below where the bullet will sit on the powder charge. Me thinks that 44 grains will put the bullet on the charge and clean up the crap in the bore. Try again tomorrow...

[sundog]

44.0/7383 and a Sierra 150 Spitzer SP is the cat's meow! Meow! Shot way high from the cast boolit setting, so shooting a lower aiming point put 3 rounds in two holes at 100, less the an one inch. Buddy shot the other five we had loaded and shot about an inch and a half, and he said he pulled one. I've got the rest of the 50 rounds loaded now, and next outing to the range we will do a scope adjust (and maybe the base) and zero. 44.0/7383 will tap down to the base of the neck and the bullet sits nicely on the powder column with no space. It leaves a little trash in the barrel, but what the hey! Might even get to chrono this load next..., maybe, got get a good zero first.

[Jim]

.... Shooting a lower aiming point put 3 rounds in two holes at 100, less the an one inch. ....


That's what I'm talkin' about!!