I have always believed that a powder as manufactured is the same if it is the same manufacturer and same number. For instance IMR4350 made 20 years ago should be identical to IMR4350 made tomorrow. Red Dot made 50 years ago should be identical to Red Dot made yesterday. etc. But I have had several people (on the internet) say that powder formulas are changed by the manufacturers from time to time. Is this true? If so, wouldn't the powder be renamed or renumbered? I just can't see lawyers letting them change the burn rate without changing the label. Does anyone have a definitive answer? Thanks

my understanding is that from the warnings. that each LOT in a given powder may change. It states to reduce you load and work back up.
The disclaimer.

They do keep the same formula; usually. For example, old Unique smokes like black powder, but recent lots (last 25 years is recent to me) is clean.
They have to, for safety; As stated, lot to lot variations do occur.
War story; whilst in the Army, one of my jobs was working as a Tank Ammunition production manager. I had to order the cartridge case, (105mm), projectile, primer, propellant, and LAP (Load, Assemble, and Pack), . For the propellant, they never used the same amount from lot to lot as it was not the same; it was Blended to make it as close as possible. They might do that for small arms too, I don't know.

One example of change in formula is Hercules 2400. When Alliant started putting their label on "2400" the powder changed slightly and though it shares the same name as it's predecessor it is not the same product. I have never experienced any noticeable difference from one production lot to another of the same labeled powder that I have used, but that is not to say that it never happens. I think the manufacturers put that warning on their containers to cover themselves a little from tort liability.

The recommendation to verify results from lot to lot is a good one. The problem isn't that every lot is different. If all goes as it should every lot should perform the same. Manufacturing practices are so good you could probably go forever and never see a measurable difference between the lots you procure and use. However, source materials and manufacturing processes are not always perfect. And the powder you have may be very old or might have been stored in extreme environmental conditions. The concern is that you might get that one rare lot that is very different. Therefore, it is always prudent to test each lot.

Let me tell you a little story. We used to use a great deal of military blasting fuse. It comes in cylindrical tins that contain 500' of fuse comprised of 10ea 50' rolls. The proper practice is to conduct a test burn from each can you open to determine the burn rate for that particular can. You must know the burn rate to calculate the exact lengths of fuse to cut. Fuse from most cans burns at the same rate but every now and then you get some fuse that burns slightly faster or slower. The variations were so minor that sometimes I would catch a soldier forgoing the burn test altogether and just cutting fuse lengths based on the "normal" burn rate. What difference is a couple of seconds one way or the other?

One day I opened a can and proceeded to conduct a burn test. I watched in amazement as the fuse would at the normal rate of about 40 seconds per foot for a few seconds then, with a pop and a jump, it would jump ahead in 6" spurts. The test piece that should have taken about 2 minutes to burn took about 20 seconds! I tried pieces from every roll in the can and they were the same. If I had been using that fuse the results could have been catastrophic.

Over the years I used hundreds of rolls of time blasting fuse and I never had anything like that happen again. But it really drove home the notion that you can't blindly trust in manufacturing processes to protect you from a rare but dangerous variation. After that, I made it a practice to test every roll.

I know, blasting fuse isn't smokeless powder but the basic principles for safety and checking lots still apply. Have you never heard of certain lots of ammunition or powder being recalled by the manufacturer?

I don't know about all of them, but I know Accurate Arms (Western Powders) changed the formula for AA4350 and AA4064 in recent years. They are not the same as IMR any more, but still have the same designations. Here is the email:

quote:

Larry,
No it is not true now. Accurate 4064 and 4350 are slower burning than IMR4064 and 4350.

Don W.
CSR



406-234-0422

www.westernpowders.com
www.ramshot.com
www.accuratepowder.com
www.blackhorn209.com
www.montanaxtreme.com
https://www.facebook.com/westernpowders?fref=nf


From: Larry
Subject: Accurate Powder: Contact Us - General
Question Type: General
Question Type: 4350 and 4064 manufacture
I have loaded with Accurate powders for a long time. At one time the reloading manual stated that 4350 and 4064 were identical in every way to the IMR versions. I understand lot to lot variations. Is that still true?
Thanks for your help.

Maybe they should use "new and improved" like other products !
I remember shooting a combat match and someone said there was a different muzzle blast from start vs finish of the match. All I noticed was the early version was dirty , the later was clean.
Muzzle blast ,muzzle flash ,burning rate, cleanliness can all be changed without notice . Ammo companies always load to pressure more than velocity.
Many are improvements .Massad Ayoob has a book with the cover photo illuminated only by muzzle flash .12"x6' muzzle blast .He couldn't do that today without the modern additives !!

Grenadier's analogy is correct. IIRC you are buying a BURN RATE of powder, not necessarily a formula. So H4895 has a particular burn rate. It might be made in different factories and different countries and to slightly different formulas but the burn rate is supposed to be consistent can to can. That is why it is called canister powder.

About 10 years ago the formulation on H-1000 was changed. In a 300 Win Mag with 180 bullet the max charge was reduced by 2 grains for equivalent pressure and velocity.

quote:

Originally posted by Blacktailer:
Grenadier's analogy is correct. IIRC you are buying a BURN RATE of powder, not necessarily a formula. So H4895 has a particular burn rate. It might be made in different factories and different countries and to slightly different formulas but the burn rate is supposed to be consistent can to can. That is why it is called canister powder.

That is interesting info.

I would add that there may be variations in for instance, IMR 4831 made today from the same made 40 years ago, simply due to slight variations in supply sources of the chemical make up over time. I could easily see those sources changing several times over an extended period. Sometimes sources run out, and sometimes companies go out of business. And just like you can go from one location to another and experience differences in water quality, (which is an exaggeration to illustrate a point), there may also be minute variations in different chemical sources.

Some of Herculese/Alliant powders have changed and are so advertised, but they are supposed to have the same burning characteristics with regard to load data. the one that comes to mind is Red Dot, which they claim is improved and cleaner burning.

I hope they keep the formulas the same, but how can one know for sure.

Powders are more than just burn rate.

For example, H4831 is a single-base powder, while Norma MRP is a double-base powder (ie., MRP contains a bit of nitroglycerin). Yet, both have very similar burn rates.

Coatings are also variable. It's more than just burn rate.

MRP is more temperature sensitive and contains more potential chemical energy per grain, whereas H4831 contains less energy per grain (i.e., no nitroglycerin) but is less temperature sensitive as a result.

I specifically bought 3 large containers of Reloader 7 in the old formula ( same lot number) made in the USA. The new formula says made in Sweden? Anyway, the old stuff seems to be a bit faster burning. There is a difference.

Col. Nonte addresses this in one of his books. The manufacturers have machines and they load them qwith chemicals but they do not know exactly what will come out. Yes, they can tell you if it is going to be flake, or string like cordite or spagatti, or ball ??? After the machine has run they take a test sample and run a "burn rate" test. Most is bulk packed and sold to large ammo manufacturers who have labs and test each batch of cartridges... IF it is close to a "commercial burn rate" it is set aside and blended with similar batches and "coated" and other additives added to get it within the "commercial burn rate." This goes into the commercial cans/bottles etc. No, it is not the same from one "lot" to the next. The dumbest thing anyone can do is pull a cartridge apart and assume they can guess the canister powder it was loaded with. Stocking a certain lot is common practice. I knew a gunsmith whose son was on Gary Anderson's list for the team because he was left handed like Gary. He told me that Gary was complaining that Hodgdon had changed the 4895 he had loved and it was no longer as predictable, whatever that means. I am not fit to tie Gary's shoe laces. Yes, it is the same basic chemicals, but the exact mix varies and you must BEWARE! Happy Trails/ Happy Holidays.

quote:

Originally posted by iiranger:
Col. Nonte addresses this in one of his books. The manufacturers have machines and they load them qwith chemicals but they do not know exactly what will come out. Yes, they can tell you if it is going to be flake, or string like cordite or spagatti, or ball ??? After the machine has run they take a test sample and run a "burn rate" test. Most is bulk packed and sold to large ammo manufacturers who have labs and test each batch of cartridges... IF it is close to a "commercial burn rate" it is set aside and blended with similar batches and "coated" and other additives added to get it within the "commercial burn rate." This goes into the commercial cans/bottles etc. No, it is not the same from one "lot" to the next. The dumbest thing anyone can do is pull a cartridge apart and assume they can guess the canister powder it was loaded with. Stocking a certain lot is common practice. I knew a gunsmith whose son was on Gary Anderson's list for the team because he was left handed like Gary. He told me that Gary was complaining that Hodgdon had changed the 4895 he had loved and it was no longer as predictable, whatever that means. I am not fit to tie Gary's shoe laces. Yes, it is the same basic chemicals, but the exact mix varies and you must BEWARE! Happy Trails/ Happy Holidays.

Yes. I had a friend, now long since passed, who worked in an ammunition plant during WWII. They would get train cars of bulk powder delivered and test it to get the velocity and pressure curve needed to operate in an M1 with M2 ball then turn on the machines and load millions of rounds. It wasn't like they had the luxury of rejecting a shipment because it was different from last week's.
The stuff sold retail is, of course, much more precise because somebody might take a load from a 25 year old manual that worked fine when they used it last time and buy another pound of powder and start loading. So 4831 better be close to last years 4831 and not the equivalent of Red Dot.

Let me throw something else into this.


Over the years, we have found that the same powder, same lot, in the same rifle, give different results when used a few years apart.

And it is not very consistenat in the sense that the velocity goes dow, or up.

In some rifles, the velocity goes slightly up.

In others, the velocity goes slightly up.

I have no idea what causes this.

It could be due to the barrel??

It is just one more thing we should bare in mind when reloading.

AI User . . .

I think you missed the point.

\\Powders are 100% based on burn rate when compared to other lots of the SAME powder.

Bullseye is not 4831 nor is it MRP, but one should compare Bullseye with itself, NOT other powders for the sake of this discussion anyway.

This is a very interesting subject.
Several years ago, I contracted to the plant here in Australia that makes the majority of Hodgdon powders that are re-packaged and sold in the US.

For a CANISTER powder to be sold as it's designation number, ie H1000 (AR 2217 here) it MUST be within 3% of the ORIGINAL pressure,burn,temp,time and ALL other parameters found in a calorimeter bomb.
If it doesn't comply with ANY of these within the 3%, it is classified as BULK and is shipped as such to be blended for factory/military loading.
It is NOT blended to make a burn rate, as many believe, factory/military ammo is blended. The formula, shape, size and coatings/additives are ALWAYS the same when the powder is made, just like a cake, there are subtle differences from batch to batch.
As far as I know, H1000 was never changed, however, a certain batch of H1000 and Varget were at the extreme limit of being different in burn rate and were pulled from the shelves due to pressure issues. This has happened with many brands of powder, not just those 2.

Also, even if numbers are the same, such as the 4350 made by a few different companies, DOES NOT mean they are the same burn rate, AND, burn rates are a very rough guide that can and do change depending on which cartridge is being loaded.
Burn rates are based, loosely, on a Relative Quickness scale, now, this RQ scale is not governed and therefore differs between manufacturers. IMR rate IMR 4350 with a RQ of 100, this is their standard they measure ALL OTHER POWDERS against. Other manufacterers may choose a totally different powder in burn rate to give their powder a RQ rate of 100, in fact, ADI/Thales gives H4895 (AR 2206H here) a RQ rating of 100, totally different burning characteristics of IMR4350.

So, in essence, it's all heresay and guessing as to what 'pigeon hole' a powder belongs in.
I know from extensive testing with a pressure trace, that RE19 and RE22 will swap places in regard to which is slower burning in SOME cartridges, such as the 338WM, 30-06 and 270.

Hope this helps you understand that powders are kept within 1.5%+/- of the original burn to keep us all safe, sure, some things slip through, but, mostly it is very minor and subtle changes that we find, a few fps faster or slower is not a big deal.

Cheers.

quote:

Originally posted by Saeed:
Let me throw something else into this.


Over the years, we have found that the same powder, same lot, in the same rifle, give different results when used a few years apart.

That IS peculiar. I assume that means that the specific performance of a given box of factory ammo could also vary depending on how long it is shelved. Hmm..

The US military had/has a shelf life on ammo, powder does deteriorate. Lots of people have 30-40-50 yr old powder that is in good shape, but there are batches out there that for some reason do not last too long, even being stored "properly".
This article was what I read about it, it has some validity as far as I can tell;

http://forums.thecmp.org/showthread.php?t=157820

I shot red dot in my 20ga since 1968 then a few years back I got a new manual. I noticed max was two gr lower the what I had been using for decades.

I reduce my loading and continued on.

A little easier to search:

http://www.ilrc.ucf.edu/powder...tail.php?powder_id=1