Burning rates !

[Papa smurf]

Getting back into reloading after many years , I was concerned about the changes in burning rates of posted on this forum by some of the "experts". An email to Alliant removed all my worries about my old data . The reply was "John if we had changed the burning rate of Unique we would no longer call it Unique " . Now my only concern is some of the information posted by those "experts". There are too many people reloading that should not be ! --------------------Papa

[Maven]

Can't argue with Alliant's answer or your last sentence, Ps!

[Ola]

So what are the experts saying?

I mean, it is common knowledge that there is small changes in burning rates even between different patches of powder. But if the manufacturer is any good, the powder is always safe to use. MOST of the users don't even notice the differences.

I happen to know one European powder manufacturer that tests every patch throughly. If the burning rate is right and same through out the patch, the powder is bottled and sold to reloaders. If it is NOT, the powder sold to a cartridge company. And no, it is not Vihtavuori..)

[Papa smurf]

Ola : I'm 78 and been loading and casting since I was 15, so I have had the advantage of the knowledge of many , some have long been gone . So my question to you is just how is it that you know happen that you know ? Been there or been told ?--------------------Papa

[Ola]

I was told by a a staff member of that powder company.

As far as I know, it's not a secret of any kind. The point he was making: the powder sold to reloaders is "the best stuff" this company is able to do. The "good stuff" is sold to cartridge factories that can make pressure tests and adjust the powder charges if necessary.

[Papa smurf]

So , first you say we get the "good" stuff , now you say the cartridge factories get it . Make up my mind !

[Ola]

Sorry. :)

We get the BEST.

Factories get the "usable, ok, good BUT NOT PERFECTLY spot on" stuff. Because the factories can determine the properties of the patch and adjust the loads.

OK?

[JonB_in_Glencoe]

I'd be curious as to which expert made which claim?

In the last decade, 2001 I believe?
Alliant made the claim that they have made Unique "cleaner burning" here is a good read about it.
http://www.gunblast.com/Unique.htm

ANYWAY, that has spawned some discussion on our forum, like this thread:
http://castboolits.gunloads.com/showthread.php?306255-0ld-Unique-quot-VS-New-Unique-Any-Better/page2
But I haven't seen any posts that stated anything to be "warned about", like it is now a different burn rate. Of course, I haven't read every post.

[bruce drake]

Its may be cleaner burning but its more than likely built to the same burn rate as the older powder formula.

They do it more for liability sake than anything else. Imagine the public relations fight if a powder company changes the formula of a powder that has been on the market for a long time to the point where the burn rate of the powder is significantly faster or slower than the published data that is out in the public domain.
then old Snuffy Smith picks up a fresh bottle of the new formula/old name powder after the keg he bought in 1978 finally runs out on him and proceeds to load up a ripsnorter of a pistol load for his 44 Magnum after consulting the 1978 Speer loading manual (that he bought with his original keg of powder) and determining that his max load he's been using for the last 30 years is still good...and the new powder (which may be like 40% faster than the old formula) proceeds to blew his pistol and his hand apart from the out of synch load data...Powder bottle has the same label as his old keg but the powder is definitely different with much different effects as well...
Should it get a new label if the powder burn rate is different? Of course it should. probably one of the reasons why the new IMR Enduron line of rifle powders have their own number designations(4166,4451, 4955 and 7977). The copper cleaning additives in the new powders don't allow them to be lined up with the previous powder number designations for the company. In fact the four new powders due to the additives aren't recommended for small cases due to their slower burn rates.

http://www.imrpowder.com/PDF/Burn%20Rates%20-%202015-2016.pdf

[jonp]

Formulations of popular powder may have changed but from what I have read it is only to make it cleaner. The load data may change in the books but I suspect it is more due to more accurate measuring equipment than anything. A small variation in lot's is expected but not enough of a difference for 99% of us to notice.

If a powder company radically the formula and burning rate they would tell everyone and sundry and give the powder a new name. That's common sense.

[Bent Ramrod]

It's all "the best stuff."

When the smokeless powder comes out of the processing machinery, it is in the familiar sticks, flakes, kibbles or whatever. The formula of what percentage nitrocellulose, colloiding agent, stabilizer and (if there) nitroglycerine has been adhered to.

The burn rate, on the other hand, can be markedly different, even of batches of the same formulation in the same size and shape. So samples go into a pressure bomb and a burn rate curve is established for that batch, or "lot." This data is supplied to the ammunition company that purchases that lot, and the ammo company has its own pressure bombs to confirm the data and adjust the loading for pressure and performance in the "lot" of cartridges it loads with that particular lot of powder.

The home reloader does not have this pressure measuring apparatus, and it is a poor idea to measure unknown pressures in the chamber of a firearm. So the powder companies select the batches of powder that are closest to a given standard, and blend them together until the pressure curves are identical with that standard. This blend (a new "lot") is the "canister grade" powder that is sold to handloaders. It has been formulated, sized, shaped, and blended to conform with the specifications of Unique, 3031, or whatever familiar number or name the handloader wants to use.

This is why we are cautioned to be wary of breaking down factory ammunition and using the powder in the shells. It may look exactly like 4064, but it is not, exactly. A company like Hodgdon, that broke down tons of surplus ammo for the powder, had its own measuring and blending equipment so they could produce a canister grade standard like 4895, and a recommended list of cartridges to load with it. The smaller outfits that get "data powder" from such sources, have more abbreviated lab facilities and a shorter list of cartridges they recommend for loading. And even so, we are still cautioned to start low and work up.

None of the output is of a lower grade than any of the rest of it. It just needs to be matched to the application.

[reddog81]

Papa smurf,

I'd verify that your old data is still considered acceptable data and matches whats being published today. Just because the burn rate of Unique hasn't changed doesn't mean all previously published data for Unique was good. Pressure testing and standards have improved over the years and loads that were published decades ago might have been too hot.

[HABCAN]

Or the companies' new insurance agents have convinced them to lower the volumes of their published loads.

[Blackwater]

I don't think the problem is with the real experts. I think it's with the loud mouth pretenders, and those who read some data and make erroneous assumptions based on their perceptions, and not on real, hard data or info. There are a lot of "internet experts" around, but an awful lot of what's posted is opinion and NOT real fast rules, like some make it out to be. Add in that even a single powder can burn at one rate relative to another in two different powders, working at two different pressures, and the plot thickens. Powders are a mixture of chemistry, granule shape and the pressure they're burnt at. Some powders (think 296/H110) don't burn well at lower pressures, and rumors have been around that underloading it can even blow up a gun, potentially. Some don't like being pushed at higher pressures, and pressures skyrocket as pressure rises.

These are some of the reasons we should NEVER use any but good, verified data, unless and until we know enough about the powders we're using to feel comfortable inching up in some guns, but even then, it MUST be very slowly and methodically and incrementally. It's a lot like the old saying that some learn from observing others, some from personal experience, and a few have to pee on the electric fence to see what happens. And too, the more we try to make things "foolproof," the bigger the fools we seem to manufacture in the process. Life's full of paradoxes. Caution is for the sane reloader. Taking things for granted is for those who have lost the ability to think and reason, and figure playing with things that CAN, if used improperly or unwisely, blow our butts up, "ought to be fun!" And even the most careful among us is capable of making a mistake. There are only two types of reloaders: Those who've made a mistake, and those who are going to. Reloading is something many pursue in too big a hurry. That's very fertile ground for mistakes or accidents. Just don't be one of those who is unwise, and your odds get tremendously better.