IMR 7383, what's it compare to?

[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