I am assuming that a reference to "4831" in a Hornady 1973 load manual would be referencing IMR4831 & not H4831?

quote:

Originally posted by Mike_Dettorre:
I am assuming that a refernce ot "4831" in a 1973 load manual would be referencing IMR4831 & not H4831?

look at bottom of page on this link*(In manuals or writings published before 1973, any mention of 4831 will refer to Hodgdon’s H4831. In older manuals, it was customary to list the powder simply as A4831†with no designation connecting it to the Hodgdon line. The reason for this is simple; prior to DuPont’s introduction of IMR 4831 in 1972, the surplus 4831 sold by Hodgdon was the only powder to carry this designation. Despite their similar nomenclature, these two powders (IMR 4831 and Hodgdon 4831) are not interchangeable and must not be confused. IMR 4831 is significantly faster burning than H4831, and may produce dangerous pressures if used with data developed for the latter.)

We a couple more questions then. None of the powders in the 1973 manual carry a designation of I or H. They simply state the number.

Whether it is 4350, 4895, 4831 or 4064 etc.

So it would seem that since IMR 4831 did not come out until 1972 that a manual published in 1973 would likely be H4831. Anyone feel free to comment on this assumption.

probably. ?? but?? Why use reloading data that old?

quote:

Originally posted by hivelosity:
probably. ?? but?? Why use reloading data that old?

This is a very good post.....data is available free on the internet and is free at every store that sells gun powder.

Lest we forget....there is also AA 4064, 4350, and 4895 etc.....

If the data is not clear which one we're talking about.....loose it!

To the extent possible never rely on a single data source. I like about 5 if I can find them and then I throw out the high and the low.

Guys I appreciate the comments...but who says that I am even relying on the data...I am just curious about the data...

Can anybody answer the question asked as opposed to pontificating...

Put it to rest the easy way. Call Hornady and ask them what they meant in their manual. They are the only one whose word I would take in such a matter. Anyone elses is just opinion.

Let's try to keep this simple. Powders designated 4198,3031,4895,4320and 4350 are all IMR powders made by Du Pont with one exception. There were two versions of 4895, the Du Pont and Hodgden's. Hodgdens was a mixture of all the surplus versions of 4895, blended to make one powder. While surplus 4895 was made by Du Pont for use in 30-06 ammo during WW-2, the burning rate varied from as fast as 4198 to as slow as 4320. Hodgden blended the whole pile to have one burning rate as close to the commercial IMR version as possible. At one time, they were considered interchangable.
I can remember buying 4895 through the NRA and each time there was a loading sheet which gave loads and said use data for 3031, or maybe 4198, depending on the lot number of the powder.
I've never been able to find out exactly when 4895 actually was originally made, but references in 1945,46 and 47 copies of the American Rifleman brought the various burning rates to light.
I have heard that the difference in burning rates of surplus 4831 and IMR-4831 was due to the age of surplus 4831 causing it to be slower burning. Supposedly, when the supply of surplus 4831 ran out due to deterioration, Hodgden had it matched by some company in Scotland so that data would stay or be very close to the same as for the surplus. I can only assume that to be correct as the load I used in a .270 with surplus stayed the same whn I had to go to the "new" Hodgden's version.
Paul B.

Lots of confusion and unfounded theories floating around out here. Let's clear some of them up.

First, in the 1973 Hornady manual, the powder referred to as simply "4831" is the original surplus powder distributed by Hodgdon. To confuse matters a bit further, this surplus 4831 was manufactured by DuPont and was one of the IMR series of powders. It was simply never previously available as a commercial powder, much like IMR-7828 was not available as a commercial powder for many years.

The next "4831" to come along was the newly-produced IMR-4831 made by DuPont. It was NOT an exact copy of the original (nor was it simply faster due to the orginal getting "slower" with age -- a discredited myth). Compared to the surplus powder, newly-manufactured IMR-4831 was significantly faster, being very little different from IMR-4350. But that's not too surprising since the surplus 4831 was sometimes referred to as "4350 DATA powder". No matter the designation or the source of the data, newly-manufactured IMR-4831 was simply faster than the surplus stuff.

Not long after the introduction of newly-manufactured IMR-4831, Hodgdon's stocks of surplus 4831 were depleted, so Hodgdon turned to ICI of Scotland to manufacture a replacement. Hodgdon and ICI did an amazingly good job of duplicating the speed and burning characteristics of the surplus powder, so newly-manufactured Hodgdon 4831 acted pretty much like the surplus that shooters were accustomed to. In subsequent years, Hodgdon has changed their supplier to ADI of Australia, who now manufactures their "H-4831". Insofar as I know, it also does a pretty good job of duplicating the surplus powder from WW II.

Now, as to 4895: Surplus 4895 stocks were gone some years before the 1973 publication of the Hornady book. 4895 was also a DuPont product of the IMR series. DuPont had, by the time of the Hornady manual, been producing IMR-4895 as a cannister powder for a number of years. Similarly, Hodgdon had long since run out of its surplus stocks and had turned to ICI to manufacture a replacement. The IMR- and H- versions of 4895 were so similar in performance that most reloading manuals of the day did not specify any difference in the two, considering them interchangable. In my experience, the two 4895's were about as close as any two given lots of the same powder, so this was a reasonable thing to do.

Since the IMR series of powders were all represented at the time of Hornady's publication by only a single powder, or in the case of 4895 by two duplicate powders, Hornady simply deleted the prefix of "IMR" in front of their numbers, as did many reloading references at the time. Not long afterward, as both reloaders and publishers became more sophisticated (and more powder variations became available), powders were identified more concisely.

As an aside on the relative speeds of the two powders, I have found IMR 4831 to be closer to IMR-4350 than to surplus 4831. Also, surplus 4831 is closer to IMR-7828 than to IMR-4831. In other words, the four powder fall into two general speed groupings: IMR-4350 & IMR 4831, then H-4831 & 7828. Please note, I'm not saying these two groupings represent identical powders, just that there seems to be more gap between the two 4831's than between them and the powders on either side of them.

I have never personally loaded with IMR 7828 (never had the need), but all the rest of what stonecreek said immediately above, I believe to be well put and correct.

(Additionally, some early [WW II]versions of IMR 4895, were so dissimilar between lots that their data immediately after the war was pretty much always published as "4895- lot # such-and-such", despite no differentiation in later year's books.)