Are we all willing to put this thing to bed or does some dear heart have more information to share? There are I believwe some loose ends to be tidied up. For example why did the 45/70 have overload problems? Depending on what replies are received I will deside to give this scynario more time to devlope or start to try and put together a comprehensive report. Anybody out there got something to say? roger

What overload problems? My .45-70 problem was no mystery. I was using a slow-burning powder in a cartridge having a high expansion ratio with a light-for-caliber bullet (low sectional density), and it only partially burned. An underload, not an overload. Can't pack enough in there to make it burn efficiently. Would've been a similar result with a similar charge weight of any powder of similar burning rate. Some folks don't mind having lots of unburned powder, and with single shots it's probably no big deal. But those slightly burned long tubular grains jammed my 1895 Marlin so the lever couldn't close.

I've already put this to bed, as far as I'm concerned.

Dirty cartridges? Residue? Unburned powder? SAY WHAT?



Hi, Maven: I'm glad you spoke up and provided the details about your experiences with what is turning out to be a real "rogue" propellant.



Here�s what I think is the bigger picture:



Perhaps it is best that those of us who use this stuff had better start over from the beginning in evaluating it and we MUST NOT rely on any load data given by any other user of this stuff because there is a high probability that it amounts to using the wrong data. IN OTHER WORDS, WE SHOULD NOT SWAP �RECIPES� ON HOW MANY GRAINS OF 7383 TO USE WITH A GIVEN WEIGHT BULLET AND WE SHOULD NOT LOOK TO ONE CANNISTER GRADE POWDER AS THE ONE TO USE AS A GUIDE. Maven, I guess that was what you were alluding to.



What we need to do instead is develop a testing method for developing safe loads for each individual jug of powder so that each individual user can safely develop loads on his own. What needs to be emphasized here is that each and every user must have some way of knowing where to stop in working up loads. The way we are doing it now amounts to using 4350 data for 4064, or visa versa, and then we get all confused and pi$$ed off because nothing shoots right, it either unpredictably shows high pressure signs or barely gets the bullet out of the barrel and leaves it full of mummy grains. It doesn�t have to be this way, either.



The three powder lots available at the time H.P. White Laboratories tested the loads for the .30-06 with 147/150 grain projectiles were loaded at 52, 53, and 56 grains respectively and used regular primers. The manufacturer of the brass and primers was not mentioned. That is a spread of close to 12% right there (using 52 grains as a baseline)! To get a better perspective on that, a 12% load difference is pretty close to using .30-06 load data for a .308 Winchester! No wonder this stuff is giving everybody fits!



I suspect that there are more than the three lots of 7383 that H.P. White Laboratories tested and are listed on Hi-Tech�s data sheet. If you remember some time back, another powder distributor (Jeff Bartlett) was selling two different lots of WC852 that he labeled WC852Fast and WC852Slow. Neither was like H-380, one being like 4064 and the other like 4350 or 4831 and this is another case like that, EXCEPT WORSE.



Maven, since you pretty much used the same methods I used to arrive at what seems to be safe load levels you are probably okay with whatever the powder is that you have. One of the criteria I used in developing my loads was stopping just at the point where the powder burned cleanly and then not going any further. Actually, my lot of 7383 was not all that dirty to begin with, nothing like Purina Rifle Chow (IMR5010), WC860, and WC872, where the cartridge case and barrel were left teaming full of tawny-colored little mummies. Nope, not at all like that!



My lot of IMR7383 weighs 12.355 grains per cubic centimeter, with the powder in the measuring container shaken and tapped gently down to maximum density and then struck level with a straight edge. I used a Lee 3.1 cc dipper that is supplied with the .308 Win and 7.62x54R reloading dies set.



Linstrum

Do you mean IMR7828?

Bill

Yesterday my cousin shouted over to my bench that he had just popped a primer in his old Ruger .270. He had never popped a primer in his 40 years as a rifle man.He was using a 150 grain psp bullet a win mag primer and 52 grains of 7383 in Federal once fired cases.

I told him to try another shot and he did and everything looked great no excessive pressure sign. The third shot looked like the last exhibit to Clark's experiment on controlled overloading. Horrible disfiguration of the case base.

All the bullets were pulled , the powder weighed and the cases measured.The powder was all a little below 52 grains and all the case measurements were within tolerances. What we found was that the round that exhibited no pressure was an RP case that had gotten mixed in with the FC cases my cousin was using. All the FC unfired case necks were much harder to the bite test than a number of other cases.

All the bullets pulled had more severe pull marking than any I ever saw.

From all the experimenting I've done I would have sworn an overload as seen here with 7383 could not happen. From everything I've seen you just could not get enough 7383 in the case to even come near max pressure. I WAS WRONG.

At some time on this forum one of our more renoun members made a comment to the affect that " If you ever succeeded in burning all that hard to ignite powder in the case you're going to find you got too much." His words have a new meaning for me today.

With 49 grains of 7383 and the same bullet and primer in RP cases we had a noticeable amount of UNBURNED powder and low pressure.

I for one would like to be able to gather all the data from those of you who have used 7383 to some large extent, analyze it, discuss it and jointly post the data and our individual thoughts about it. My E-Mail address is listed. roger

The .270 still shoots better than 3/4" at 100yd.

"Do you mean IMR7828?" No,Blue Moon. IMR7383 Surplus 50 cal. spoter cartridge powder. Some say tracer.

roger

'How about miking the bullets they sound like they might be 7mm instead of 270. " I guess I thought that would be taken for granted. We miked the bullets.Thanks ,Doug.

John, in the 30-06 and a full case of 7383 I had some unburned powder with all 150gr. bullets. Only when I got to 168 gr.bullets was I not able to find unburned powder.Again I realize there are a lot of variables that could cause a difference in our results. What Might save someone injury is if we pooled our info and jointly studied it and took some action to inform our shooting brotherhood. One story I've received so far is really scarry.

I might add that it was my intent when I originally posted this thread to get you and Paul involved knowing that you have both have reflected on your findings. roger

bartsche,

I have been shooting surplus IMR-7383 (Lot # RAD78L 47985) in the 30-30 and the 7-30 Waters cartridges. I am using it exclusively with cast bullets. I know many people indicate a burning rate of 4350 or very near that. WELL, in the cartridges I listed, it is much, much closer to H-380. SO, if your lot is the same as mine and it continues to have the H-380 burn rate in your 270 Winchester, 52 grains would be over maximum. Hodgdon lists 50 grains of H-380 as maximum for a 150 grainer. They recommend a reduction of 6% to start with so that would be a starting charge of 47 grains of H-380. I do shoot cast bullets in my 270�s but I have not had the chance to try the IMR-7383 yet. Keep us posted as to further load developments with the IMR-7383. Good-luck�BCB

Roger, As you know, I've been using IMR 7383 in my .243Win. (Ruger #1) with standard LR primers with nary a problem. However, with 85-87gr. [jacketed] bullets, I won't use more than 41.5gr. in warm weather or 42gr. in cool weather so as to avoid "pressure incursions." Accuracy is better than 1 m.o.a. and velocity is ~3,100fps, which is more than enough for my needs. In my .243Win., my lot (will have to check the lot no. tomorrow) of 7383 is virtually the same as IMR 4350. I've also used it in the 7.5 x 55mm Swiss (35gr. and standard primers) with 178gr. cast bullets with no apparent problems, but I do wish I'd chronographed them. Ironically, the only problem I've experienced with excessive pressure occurred when I used Remington factory ammo. in the .243 in March as I reported here. Coincidentally, I was thinking about using 7383 with 150gr. SP's in my 8mm Mau., using IMR 4350, or now, H 380 data as I don't have any IMR 4064 on hand; but I'll start with the min. charge listed for either powder. In any event, how much speed does one need to punch paper? Regards, ...Maven

Roger, you've already seen my data. Only things I've tried it in are .30-06 and .22-250 so far. In those I've noted the similarity to 4350 and been unable to approach a maximum load with 150-168 grain bullets in the .30-06 and 55-60 grain bullets in the .22-250. I've known it would take more careful working up in Magnum cases or with heavy for caliber bullets in others. I'm sure the comparison with 4350 is only valid under limited circumstances. Remember, that .50 Spotter cartridge had a maximum average pressure of 38,000 PSI, so maximum loads in modern rifle cartridges are running it above the pressure range for which it was designed; its burning rate will vary a bit depending on the conditions. This powder was developed especially for the .50 Spotter cartridge and never used in anything else.



Oh yeah, as for that "if you ever get it to burn" remark, that would certainly be a problem with reduced loads and cast bullets (as I found with my .45-70, in which I only tried it briefly and discarded it as unworkable due to the unburned powder), but in the full case loads in the .30-06 and .22-250 there's no unburned powder. A magnum primer is unnecessary, reduces muzzle velocity and increases velocity spread and group size in my limited testing in those calibers. A bit disappointing, because I use them with the compressed charges of WC860 and WC872 I use in .300 Weatherby and 7mm Rem Mag and hoped I could standardize on a single large rifle primer.

How about miking the bullets they sound like they might be 7mm instead of 270. I would check that. You did mention they pulled hard,
Doug

BCB, Thanks for the reply and I will keep you tuned in.I can not for the life of me understand why anyone sees a similarity between any make 4350 and 7383.Kinda like the similarity between a Clydesdale and a Zebra.Well anyway enough horsen around. roger

I found some of my old data on the IMR-7383 and IMR-4350 for the 30-30 and some data for the IMR-7383 in the 7-30 Waters. I can�t seem to locate my IMR-4350 data for the Waters. Anyhow 31.0 grains of 7383 produced 1688 fps and 31 grains of 4350 produced 1466 fps when fired from a Super 14� using a 311041 bullet. My lot of 7383 is considerably faster than 4350. Thirty-four grains of 7383 produced 2017 fps with a 287346 slug in the Waters barrel. Thirty-two grains of 7383 produced 1857 fps with the 287346 bullet. Thirty-four grains of 7383 is compressed in the Waters case. Regardless, as I previously indicated, my lot of IMR-7383 is closer H-380 than it is to IMR-4350. At least in the 30-30 sized cases. Accuracy was 1.2� or a tad less at 100 yards. Never achieved M.O.A. with the 30-30 and this powder at 100 yards. The Waters never got that good with this powder. I suspect a slower velocity might help�BCB



Just found the 7-30 Waters data using IMR-4350. Thirty-two grains produced 1696 fps as opposed to 32 grains of IMR-7383 producing 1857 fps. A difference of 161 fps in the Waters and 31.0 grains of each produced a difference of 222 fps in the 30-30. IMR-7383 is definately faster than IMR-4350 in these applications...BCB

The different velocities we're obtaining from IMR 7383 v. IMR 4350 in different cartridges is indeed fascinating: Is it due to different burning rates of the two powders or different burning rates of different lots of 7383? Btw, at least with respect to the 8mm Mauser and 150gr. SP [jacketed] bullets, the starting load for H 380 and IMR 4350 is 50gr. (Lyman #47). If you browse through your favorite reloading manual for various cartridge/bullet weight combinations, you'll find that H 380 and IMR 4350 are treated as (a) being similar, i.e., using identical starting loads; (b) H 380 being slower than IMR 4350; and (c) IMR 4350 being slower than H 380. I suppose we should conclude from BCB, et al's experiences that a given powder behaves differently (with a bullet of ~the same weight) in different cartridges and, of course, in different rifles of the same caliber. If this is so, we should expect no less of 7383. ...Maven

"Thirty-four grains of 7383 produced 2017 fps with a 287346 slug in the Waters barrel. Thirty-two grains of 7383 produced 1857 fps with the 287346 bullet."

Two grains yielded 160fps difference. BCB! Would you be interested to see what 30 grains does? All this info you are giving us is good stuff. Thank You! roger

For those following this thread here is some more information.

A number of cartridge cases were filled with 7383 up to where the neck and shoulder meet. Powder into the neck tends often to be compressed so for me only, this is a space to be avoided with this powder.
case mass
1. 22-250 Winchester 34.5grains

2. .243 R.P. 41 grains

3. .244 6mm rem. R.P. 43.5grains

4. .257 Roberts R.P. 43.5grains

5. 6.5x55 nny 42.7grains

6. 7X57 R.P. 41 grains*
* seems strange but was the same with cases from 2 lots ?

7. .284 W.W.(Vintage 1966) 52 grains

8. 7mm Rem. F.C. 61 grains

9. 30/30 PMC. 29.8grains

10..308 R.P. 40.5grains

11. 30/06 MIL 49 grains

12. .300 Win. W.W. 70 grains

13. .300 Weatherby Wby 77 grains

14. 8mmX57 R.P. 46.2grains

15. 8mmX404x2.5" R.P 375 ultra mag 66 grains

16. 8mmx404x2.5" Bell 404 65.5grains

17. .358X 404 IMP Bell 404 79.5grains

18. .270 Win. W.W. 50.5grains
It's cartridge case mass. Columating in this format seems to do what it wants. I hope you get the picture.
Today is Saterday and I'm still cleaning all the 7383 residue out of my 8mmx57 scout I shot Wed.. I guess these rough military barrels are really more suseptable to this trashy burning powder. roger