A week or so ago I posted some adverse effects with IMR 7383. The cartridge was my wildcat 358X404 IMP, cast bullets Wlr primers and IMR 7383. For those who remember there was a lot of delayed ignition.( click bang). Yesterday same rifle 225gr. Nosler ballistic tip 83.5 gr. Wcc846, WLR primer The velosity ranged from 2852 to 3029 ft/sec. 1 1/2" group and some delayed ignition. Same load and primer with 250 gr.rn gas checked cast;2662to 3010ft./sec. and some hang fires . With 2 other loads of different powders ( not ball)and CCI mag. primers the velosity was constant+or- 25ft/sec. accurate and NO delayed ignition. Am I just rediscovering that some powders realy do need mag. primers, especially when the case volume is rather large? The wcc846 in the 257 bob and .270win. does just great but I am using mag primers. So you know what you see here is just me testing stuff with different receipes. The performance of the powders mentioned here were unknown to me so I thought I'd gather some info. If you have information on the performance of WCC846,Wcc844,or IMR 7383 please contiue to share Roger

I'm surprised there aren't any replies. Paul-H I believe has a quite similar posting on cast bullets and the responses have made that post one of the most informative,I have ever seen, concerning the dangers associated with delayed ignition (click bang),{hang fire} or whatever. roger

Just saw this, Roger. I think that powder's basically just a slow burning one that needs a pretty vigorous ignition and high loading density to light off well. I'm still quite happy with it in .22-250 and .30-06 in compressed loads, with excellent accuracy and consistency though the velocities aren't as high as I can get with some more "conventional" powders. I've only used standard CCI 200 primers in these two cartridges, with 55 and 60 gr. jacketed bullets in the .22-250 and 150, 165 and 168 gr. jacketed bullets in .30-06. I use tight crimps with a Lee Factory Crimp Die, as I always do. That improves powder ignition. My charges have basically been all I could get in the case under these bullet weights in these two cartridges. With heavier bullets or larger capacity cases loads would at some point become pressure-limited rather than volume-limited. But I'm seeing no pressure signs with these.

As I mentioned in the Cast Bullets forum, there is something different about this powder from any other IMR powder I've seen. I'd noted at the very beginning of my experimentation with it that it produced a good bit more gray smoke than equivalent loads of IMR 4895 or H4350. What I didn't notice the first few times out with it (shooting with the wind at my back) but later discovered is that there's a strong, distinctive scent of ammonia in that smoke. No other IMR powder I'm aware of does that. Gray smoke and an ammonia odor are distinctive characteristics of nitroguanidine containing powders, and I suspect that this powder, made only for the .50 caliber M48A2 tracer/incendiary round for the spotter rifle on the 106mm recoilless rifle, may have somehow had nitroguanidine added to it, most likely to reduce its muzzle flash. I further suspect that it's in the surface coating, as the muzzle cloud contains all of the ammonia smell. The chambers of my rifles and cartridge cases immediately after firing smell just as they do with, say, IMR 4895. (The first-produced gas from the burning powder goes down the bore first. The last powder burning in the chamber, if it doesn't contain the ammonia-producing compound, would flush it out down the bore in any application where the bullet moves a substantial distance down the bore while the powder's burning.) One more thing I noticed when I tried it in low-pressure cast bullet .45-70 loads is that half-burned grains of 7383 are jet black, not the usual honey color of the colloid inside IMR kernels. (Carbon black is used in lots of modern powders to improve combustion at lower pressures. It absorbs radiant energy from the incandescent powder gases and heats the surface of the powder grains more rapidly, instead of letting the photons shine right through the translucent colloid.)

If this powder does have a significantly different coating from other IMR powders, that could explain some of the varying results posted by different people using it under different conditions. I would REALLY like to find someone who has the original DuPont data on this powder's composition and characteristics, or someone who'd like to analyze a sample of it to see if it contains something beside the usual nitrocellulose, diphenylamine stabilizer, potassium sulfate flash suppressant, dinitrotoluene deterrent coating, and residual solvents found in "normal" IMR powders. Although IMR powders are well known for having a consistent composition (varying only in the percentage of deterrent), there are a few known exceptions like IMR 8208M, which has ethylene glycol dimethacrylate as the deterrent coating instead of DNT. (Ed Harris says that H322 was originally surplus 8208M.) I don't know why they chose that coating for that powder and at least a couple of other military powders around the same time (mid-'60s), but there's a precedent for IMR powders that don't follow the usual pattern.

Any powder chemists out there? Or curious shooters with analytical capability?

You might find some intellegent conversation on this subject with M.L. McPherson via The Varmint Hunters Association. www.varminthunter.org

Thanks for the tip, DD!

On the varminthunter site I couldn't find a link to conatact Mr. McPherson or any sort of discussions I could read. Guess you have to join to reach those, which I haven't done. I did find his business web page, but he says he doesn't have time to answer any questions other than specific ones about anything other than getting him to rework a lever action rifle. I respect that; I'll send him a snail mail and maybe he'll be interested. I'm contacting other folks I believe might have expertise about this, like Ed Harris. Haven't heard from him yet. Stan Watson, "OKShooter," says that he never worked for the Army in small arms propellants but had heard that before they adopted the 7.62mm NATO round they had experimented with propellants from DuPont that contained nitroguanidine. He thought the advantage climed for this was improved temperature stability. He didn't know whether 7383 was one of those powders or not, but the time frame's right and it confirms that they did make such powders.

John, the one that is really a head scratcher is the WCC846.
I can accept the apparent delayed ignition and need for a mag. primer to get the stuff started. Even with the mag. primer there is a difference and that is the sound it makes leaving the barrel. Now this will indicate to you as to what great depth my scientific traning goes.

Instead of the nomal kaBOOM we get a PAAAHHrRUUUUMM and a great big flash.What rifle it is leaving at the time doesn't seem to matter either. Is it written some where-- " Hey Dummy use a magnum primer with this powder."?? I know it's not on the container from which I got it.

You mentioned the black unburned 7383 as compared to the normal yellow brown color of other unburned powder;; wellll take a look at your rifle barrels and patches that come out of them when using 7383.Ever been down in a KY. coal mine? Maybe I can reduce my rising heating costs by burning all those patches. This powder is about the dirtiest I've ever used.

You also mentioned 8208. What a great powder; clean, meters nicely, adaptable to a wide range of cartridges and gives consistant results. Thanks for your interest. roger

Lots of people just use magnum primers with all Ball powders. But a big muzzle flash from them is pretty typical and nothing to be alarmed about. They're heavily impregnated with dibutyl phthalate as the deterrent, and that stuff's a flammable oily liquid that vaporizes in the powder flame and ignites when the whole mess hits the air at the muzzle, if it's still hot enough. Dibutyl phthalate is a close chemical relative of polyethylene terephthalate, or PET, the stuff plastic drink bottles are made from. Ever throw one in the fire? They burn really well!



The biggest muzzle flashes I've ever seen from guns shooting smokeless powder are produced by a powder that Jeff Bartlett sold sometime back that he called "PSA." This stuff was made by the Chinese on contract for Accurate Arms to be AA 2230, but Accurate didn't specify that it needed flash suppressant (most spheroidal powders do contain a bit of potassium sulfate), and the Chinese made it without anything to minimize the flash. Accurate felt they couldn't sell it as 2230 and dumped it to the discounters. It's great shooting stuff, but man, does it ever flash! You should see 54 grains of it go through my .45-70 revolver under a 340 grain #457122HP! I'd be tempted to wear my welding helmet to shoot it, if I could just see the target through the filter. It's only slightly less impressive through the 22" barrel of my 1895 Marlin. Haven't yet run it through the .22-250 and .30-06, but will.



I've just been out shooting 7383 over the Chrony in my .22-250 Savage 12BVSS (26" barrel) and tang safety Ruger M77 .30-06 (22" barrel.) In the .22-250 I was using the full-to-the mouth, shaken down load that averages about 36.8 grains, extreme spread from 36.4 to 37.0. I just call it 37 grains. With 55 gr. flat base FMJs (discontinued Hornady items, I think) it averaged 3416 FPS. With the discontinued Hornady TAP 60 gr. "Barrier" bullets mentioned on another thread (just a nice standard pointed softpoint with the jacket all the way to the somewhat blunted tip), I got an average of 3256 FPS. In the .30-06 using the same 168 gr. FMJBTs that you also shoot over 52 grains (full to the base of the neck in Remington brass, to avoid swelling necks with powder jammed between the boattail and neck), average was 2527 FPS. 20 shot averages in all cases. Those velocities all match very closely with published loading manual data for 4350 in equal weights. The velocity variation in the .22-250 loads is higher than I like, surely due to my unorthodox way of loading them by submerging the case in a cup full of powder and smacking it on the benchtop 10 times. I'll try backing off slightly on the load so I can get a measured charge in the case and see what it'll do. I'm experimenting with a drop tube. The velocity consistency is very tight in the .30-06 load, which was measured through my RCBS powder measure.

I just got my barier bullets. What accuracy did you get with them and also the 30-06?roger

About 1" groups with the .22-250. I'm not an accomplished benchrester, and I shoot off one of those plastic rests with a cheap scope, and no wind flags, so that's about as well as I ever do. With the Ruger .30-06, I've never gotten better than shotgun patterns with any load. That's a source of considerable frustration to me as I know it's got something wrong but don't know what it is. Yesterday 20 rounds went into an ellipse a bit smaller than my hand, the long axis oriented 45� from the aim point. I was shooting more rapidly than ideal, just trying to get done before it got too dark for the Chrony, and the barrel was staying pretty warm, which had something to do with it. But you can't use my accuracy results as a gauge to what you might get unless they're worse than usual, and actually those are very good results for me, especially with the M77. I've shot lots of 100 yard "groups" with that Ruger with the holes pretty randomly scattered all over the paper, little better than my Mini-14 ("The World's Most Expensive Plinker") will do.

As for the dirty barrels, you're right! They're as black inside as a blackpowder rifle gets.