Powder Equivalents Chart

[Riqrob]

ADI Powders (Aus) has a powder equivalent chart on their website for various manufactures that may be handy for other newbies like me to reloading.
http://www.adi-limited.com/handloade...quivalents.asp

[rcolarco]

I guess the chart has some utility for choosing a powder when the powder you really want to use is not available. However, reading such a chart as a direct powder substitution chart is fraught with peril. It only takes a cursory perusal of a loading manual to convince you that "equivalent" powders produce significantly different results in terms of velocities and pressures.

I do not believe the disclaimer at the bottom of the chart is strong enough. I would word it thus:

"Powders with different, but similar, designations are not identical with one another, nor are they directly interchangeable. Never use a recommended powder charge with a different powder without consulting a loading manual and working up the load using good loading techniques."

[ma96782]

e⋅quiv⋅a⋅lent  /ɪˈkwɪvələnt or, for 5, ˌikwəˈveɪlənt/ Show Spelled Pronunciation [i-kwiv-uh-luhnt or, for 5, ee-kwuh-vey-luhnt] Show IPA
Use equivalent in a Sentence
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–adjective
1. equal in value, measure, force, effect, significance, etc.: His silence is equivalent to an admission of guilt.
2. corresponding in position, function, etc.: In some ways their prime minister is equivalent to our president.
3. Geometry. having the same extent, as a triangle and a square of equal area.
4. Mathematics. (of two sets) able to be placed in one-to-one correspondence.
5. Chemistry. having the same capacity to combine or react chemically.

An "Equivalent" (i.e. burning rate chart) is NOT an excuse for using the "WRONG DATA."

Reloading data is very specific.

So..........did you see it?

NOTE: These tables are only approximate, showing equivalence within about 5%.

Actual burning rates can be different depending upon calibre, weapon, loading components and practices, as well as from powder lot to powder lot. As a consequence it must be understood that we cannot accept any responsibility for the use of this information in any way.

Then, did you ever read your reloading manual's WARNINGS?

This is typical..........of what you'll find in most manuals.

http://www.speer-bullets.com/reloadi...ng_safety.aspx

Stay safe.

Aloha, Mark

PS.............people also ask about switching data, H for IMR (or vis versa)..........while still keeping the same numbers.

Something to remember (Speer #10 Reloading Manual).............

LOT UNIFORMITY

Powder manufacturers strive to maintain a high degree of uniformity between lots of powder sold under the same label. This effort has been quite successful for many years, but recently, some wide lot-to-lot variations have been found in factory-fresh canister powders. These are popular powders that are widely used by handloaders. It will be noted that specific recommendations in the charge tables are often a considerable variance with earlier Speer data, and some data from other sources. These revisions were made necessary by unexpected variation in burning characteristics in lots of the same powder.

Hodgdon's H-4831 is a very popular World War II surplus powder used with great success by handloaders for many years. DuPont introduced a somewhat similar powder, IMR 4831, in 1973. The two 4831 propellants- IMR and H - are not interchangeable. Pressure tests reveal that IMR 4831 is somewhat quicker than H-4831. Where IMR 4831 is recommended in these tables, H-4831 may be substituted. However, in no case should IMR 4831 be substituted for H-4831 data recommended by earlier Speer Manuals or other sources. Excessive pressures are a certainty with the accompanying risk of damage to a valued rifle, and worse - personal injury.

The often repeated warning to reduce powder charges whenever ANY component of the load is changed, has as much - or perhaps more - validity than ever before.

WARNING: Because of variations in powders from lot to lot, and variations and differences in components, the handloader should use the data in this manual as a guide. Do not start with the heaviest load shown. Start low, and try successively heavier charges carefully, watching for signs of excessive pressure, before increasing the charge. Many individual guns will safely handle greater charges of powder than shown here, but don't start at the top. Another reason for caution is that loads safe at normal temperatures can have excessive pressure if shot in either very hot or very cold temperatures.

Most every manual will have a similar warning NOT to switch data, "just because the numbers are the same."

Most good manuals will have a powder burn rate chart (and they are available on line).

http://www.reloadbench.com/burn.html

But, always read the WARNINGS.

*** This is the approximate order of burning rates for established brands of powder from fastest to slowest. Powders tend to switch positions especially those close in burning rate, depending upon the characteristics of the cartridge and other variables. Be sure to refer to manufacturer loading data manuals for proper charges.

My bold added.




.

[Taroman]

I find the relative burning speed chart more useful in deciding if a powder has a burning rate suitable for M1 use. IMR4895 is SO hard to get in my area now that I am looking at alternatives.

http://www.reloadbench.com/burn.html

[rcolarco]

Originally Posted by krehmkej

I find the relative burning speed chart more useful in deciding if a powder has a burning rate suitable for M1 use. IMR4895 is SO hard to get in my area now that I am looking at alternatives.

http://www.reloadbench.com/burn.html

I have gotten better accuracy from 4064 and Varget than I ever got from 4895. I use Varget exclusively now.

[USSR]

Hodgdon's H-4831 is a very popular World War II surplus powder used with great success by handloaders for many years. DuPont introduced a somewhat similar powder, IMR 4831, in 1973.

No even close. IMR4831 has been around like forever, and was a U.S. WW2 powder. Bruce Hodgdon never personally made a powder in his life. He bought the surplus IMR4831 from the U.S. government after the war, repackaged it and sold it. When his supply of the surplus IMR4831 ran out, he contract with other powder companies to make it to his spec's (it is currently made in Australia). The Hodgdon H4831 is slower burning than the ORIGINAL IMR4831.

Don

[ma96782]

Originally Posted by USSR

No even close. IMR4831 has been around like forever, and was a U.S. WW2 powder. Bruce Hodgdon never personally made a powder in his life. He bought the surplus IMR4831 from the U.S. government after the war, repackaged it and sold it. When his supply of the surplus IMR4831 ran out, he contract with other powder companies to make it to his spec's (it is currently made in Australia). The Hodgdon H4831 is slower burning than the ORIGINAL IMR4831.

Don

It might be that the editors of the manual (Speer #10, page #40) missed that one. Or, that there is some amount of mis-interpretation going on (as to the statements themselves, in context to the subject).

Hodgdon's H-4831 is a very popular World War II surplus powder used with great success by handloaders for many years. DuPont introduced a somewhat similar powder, IMR 4831, in 1973.

First off........I don't claim to KNOW the official history of DuPont or Hodgdon or of the production of IMR4895 or IMR 4831. The quote was taken directly from the manual. Feel free to write to Speer about the accuracy or for a clarification.

So...........

IMR4831 may well have been in production prior to WW2. And, I believe that the US Government probably bought powder (including IMR4831) from DuPont for/during the war.

And, Yes. After WW2 large quantities of various military powders were sold off as surplus by the US Government. That powder was then, often repackaged and sold in consumer quantities by Hodgdon to hobby reloaders. Again, probably including IMR4831. Hodgdon (probably in a marketing move) decided just to change the IMR to H and keep the same numbers.

BTW, Hodgdon was incorporated in 1952. Between WW2 and the official incorporation date, he got his start by selling surplus 4895 while still working for a Gas Company.

Of note...........Hodgdon claims (in the 25th edition of their manual).............

First to market 4895, which is recognized as the most universal of rifle powders commercially available.

First to market 4831, the slowest powder commercially available fo many years. 4831 brought out the intrinsically superior velocity characteristices of many "Magnum" and overbore capacity rifle cartridges. Still the most popular slow-buring rifle powder.

Humm........."First to market." It didn't say the company made the powder. Then not to mention........the "small print" on the labels of modern Hodgdon's powders, "Made in _______." More information about Hodgdon can be found in their manual.

Anyway, back to the subject.......

Perhaps, the Speer #10 manual (in that couple of lines) was talking about an introduction of "a newer lot or re-formulation" of IMR4831 in 1973. Not to be confused with the older pre-WW2 and/or made during WW2 IMR4831 (surplus back then, sold as H4831 by Hodgdon).

So, why not change the number?

I don't know and it's not my call.

This reminds me of like how...........immediately after WW2, H4895 was "surplused IMR4895." But today, IMR4895 should NOT be confused with new production H4895. The new H4895 is NOT the exact same thing as todays IMR4895.

So, the cautions/warnings are there.

All that being said..........THE MAIN POINT IS...........

YMWV and/or things may change over time. So, it's a good idea to have "good data" and to know that there may be variations (from lot to lot) and same numbers don't mean that you can just change data "willy nilly."

Use only data from a reputable source, start low and work your way up. Because, changing one simple component can change things.

Aloha, Mark

[ceresco]

I can find no mention of 4831 in immediate post WW2 data. The Hodgdon manual states 1950 was the first time it was used. I believe Bruce Hodgdon created it, possibly from reworking some other WW2 powders. Logically--I cannot see how 4831 could have been used. The US was mainly loading 30-06 and 30 Carbine and the 30-06 had to feed the M1s. Good Shooting......

[ma96782]

I was interested too........

The initial IMR powder was IMR4198, produced in the early 1930’s. This was followed by IMR4227 in 1934 and IMR4895 in 1941 (IMR4895 was the standard for military 30-06). Advances in ordnance drove the need for slower burn rate powders. In 1942, IMR4831 was developed for 20mm cannons. This was the slowest burn rate powder of its time. Following very quickly was IMR5010 for the 50 caliber Browning machine gun cartridge.

Taken from: http://www.imrpowder.com/history.html

Anyway......since Oct 2003 IMR was bought out by Hodgdon. So, perhaps it's only a matter of time before IMR and H powders are in fact the exact same powder? Maybe?

Aloha, Mark

[ma96782]

Originally Posted by krehmkej

I find the relative burning speed chart more useful in deciding if a powder has a burning rate suitable for M1 use. IMR4895 is SO hard to get in my area now that I am looking at alternatives.

http://www.reloadbench.com/burn.html

I've given up on the burning rate chart and have went to using data found here.............

http://web.archive.org/web/200006200...rpo/M1load.htm

Aloha, Mark


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