powder substitution - Burn Rate?

[kwm1971]

I am looking into reloading some 9mm & .40sw ammo. No specific bullet sizes yet. Titegroup is my favorite powder. I have found that Titegroup & accurate #2 have the same burn rate(9). Can I use the titegroup with the #2 recipes?

[buck460XVR]

No. Don't you have a manual?

[kwm1971]

yes i have a the lee & hornady books. I have tite group & dont want to buy other powders unless absolutely necessary.

[PhantomI]

Go to wwpowder.com. There you will find loading data for all hodgdon powders.
Tite Group loads will be listed. Good Luck.

[Mike Irwin]

NEVER NEVER NEVER use loading data from one powder to load for a powder that looks close on the burn rate charts.

I it is a recipe for disaster.

Those burn rate charts are relative. Powder five may be close to powder six, but there may be a huge difference between it and powder four on the chart.

[mmb713]

All of Hodgdon's data is available for free online. Why would you risk disaster when you can get the correct data you need as easily as posting on this forum?

http://data.hodgdon.com/main_menu.asp

[serf 'rett]

^What Mike said.

[James K]

I don't want to question anyone's data, but I strongly suggest you buy a manual or print out the appropriate company info if you can't afford one, and NOT ask for loading data on the internet.

You have no way of knowing the level of expertise of the person responding, and if you don't have the data in front of you, you could make a mistake. "Gee, Jim gave me a good answer on that load, 39 grains." Yep, but Jim said 29 grains.

Jim

[NWPilgrim]

Powder manufacturers warn against this very inclination. Burn rates are only applicable under one set of test conditions, and test conditions or calculations differ from the actual real world conditions. Different case capacity, seating depth, bullet weight or max pressure may change a powders behavior.

The burn rate is an average relative ranking. Two powders with the same rate may behave very differently at different charge weights.

[kwm1971]

*** Thanks for ALL input ***

** Found the HODGDON Reloading data online **

[Brian Pfleuger]

There is a ton of official data available online. You just have to know where to look.

[spacecoast]

Titegroup is I believe a bit more energetic than AA#2 even though they are both very fast powders (I use both a lot). They have similar burn rates, but as others have said there is plenty of free load data available at both www.hodgdon.com and http://www.accuratepowder.com/ to ever consider substituting one for the other.

[Nick_C_S]

Tightgroup, AA2, and Red Dot, are all generally considered to have the same burn rate.

BUT THAT DOES NOT MEAN THAT THEIR LOAD AMOUNTS ARE INTERCHANGEABLE.

When switching powders, new recipes must be made, and any load data from the "old" powder must be disregarded. They may have the same burn rate, but they are still "apples n oranges," so to speak.

[WESHOOT2]

I have eight separate and distinct burn rate charts.

[Nick_C_S]

I have eight separate and distinct burn rate charts.

I too have seen conflicting information. The burn rate chart I like the most is the one from Accurate Arms (also available on Ramshot's site too).

http://www.accuratepowder.com/wp-con...burn_rates.pdf

I think powder burn rates is an inexact science. I'm not an expert in the field by any means, but it just seems to be a bit like nailing jello to a wall. There's just so many variables that effect burn rate, that it can't really be clearly defined (I believe).

Using Red Dot and AA2 as an example: Supposedly, they have the same burn rate (and I am not challenging that notion here), but I find Red Dot to be very persnickity and it acts like it wants to spike real easily - I quit using it. Whereas, AA2 seems very forgiving (by "fast powder" standards), and to me, it acts like a slower powder (on the order of Green Dot, say).

[jamaica]

Powder burn rate charts are OK to give you an idea of relative burn rates. Period. They are not substitution charts. Always find a load from the Powder or Bullet manufacturer. Online or from a published manual.

[57K]

The chart I use most is Hodgdon's. Burn rates are established by the "Closed Bomb" test. All powders are tested in the same size vessel, so they very often change in burn rate specific to the cartridge you're loading. You don't want to load TiteGroup with any other data than that for TiteGroup and it can be touchy and pressure spike when Max. Charges are used.

TiteGroup is listed at 14 while AA#2 is at 25. Definitely not a good choice as far as any chargeweight or pressure comparisons. AA#2 is very similar in burn rate to ZIP and W231. In any case, it's a more forgiving powder.

[Nick_C_S]

57K said: "The chart I use most is Hodgdon's."

I find that ironic. Considering I go by Ramshot's burn rate data.

That seems like a role reversal to me

[57K]

Nick, Ramshot's newest burn rate chart has powders rated by groups rather than in numerical order as their last chart did and Hodgdon does. There were also some powders misplaced on the previous Ramshot chart including one of their own, True Blue. Lapua's latest chart also rates by groups where their previous one was by numerical order. Not that it's evil or anything, I just prefer to see powders listed in numerical order.

[Nick_C_S]

And I prefer the way AA/Ramshot groups them. For instance, AA2, Tightgroup, & Red Dot are grouped together - i.e., they're the same speed, for all intents and purposes. And of course, 231/HP-38; 540/HS-6; & 571/HS-7 are they're the same powder - so they're grouped together.

The fault I find with a numerical listing, is that #20 might be only a little faster than #21 (or even the same powder), but #21 may be a lot faster than #22 - if that makes sense. It's often a non-linear scale, so to speak. But when they're layed out numerically, it kind of leaves the incorrect implication that it is. Hope that made sense.

This is not to say that a numerical listing is not invaluable. I just like the way your beloved Ramshot lays it out.

[Nick_C_S]

It had been a while since I looked at Hodgdon's burn rate chart. So I thought I'd take this occasion to have a peek at it again.

Now I remember why I stopped looking at it. Based on years of personal experience, coupled with other data that I've seen, I see some "curiosities" with Hodgdon's chart:

It's got Red Dot (#8) faster than Bullseye (#13). No way; not a chance.

It's got Green Dot (#17) faster than AA2 (#25). No way; not a chance.

It's got HP-38/231 (#'s 28 & 29) slower than AA2 (#25). No way. Not a chance.

Yeah, I remember now. That's why I stopped using this chart.

[sourdough44]

With the 40 I'd go to a slower powder than TG or #2. I use H. Universal, works just fine in the 40.

[57K]

It had been a while since I looked at Hodgdon's burn rate chart. So I thought I'd take this occasion to have a peek at it again.

Now I remember why I stopped looking at it. Based on years of personal experience, coupled with other data that I've seen, I see some "curiosities" with Hodgdon's chart:

It's got Red Dot (#8) faster than Bullseye (#13). No way; not a chance.

It's got Green Dot (#17) faster than AA2 (#25). No way; not a chance.

It's got HP-38/231 (#'s 28 & 29) slower than AA2 (#25). No way. Not a chance.

Yeah, I remember now. That's why I stopped using this chart.

That's cute, Nick. Kinda like if John can beat up Bob and Bob can beat up Sam, then Sam can beat up neither Bob nor John! LOL.

The fact is that the powders are rated numerically based on the elapsed time required for an equal amount of powder to burn in a vessel of a specific size, i.e. "Closed Bomb". Not by their burn rates in specific cartridges or all cartridges would have to be tested, then averaged to find a cumulative burn rate for comparison. Not that I wouldn't like to see that done, but I think the powder makers are unlikely to devote the time and money to do it.

I'm gonna have to refer you to your own statements. On one hand you say that AA#2 is similar in burn rate to TiteGroup and Red Dot. Then you get pretty ambiguous with your statement that Green Dot can't be faster than AA#2 which in turn can't be faster than HP38/W231. AA#2 is not even close to being as fast burning as TiteGroup and Red Dot, and if it were, could it be slower than W231? You see, on some days, Sam might be able to beat up both Bob and John, or not! I don't believe in stereotyping whether it be people, gunpowder burn rates or even John, Bob and Sam.

[Nick_C_S]

Okay, how many people followed that? Lol.

Actually, you make a good point. I think my analogy of it being like nailing jello to a wall kinda worked too. For me personally - based on my experience - when I looked at the Ramshot/AA burn rate chart, that was the one that made me go "yep, this is all correct" without hesitation.

Powders definitely behave differently in different cartridges. Not to start another tangent: But I think 231 acts "faster" in 38 or 357 cartridges; and behaves slower in 45 cartridges. Example: I get pressure spikes right out the the gate with 125g/357 <-- you'd think the rather light 125g bullet would offer some forgiveness, but no. But 231 behaves itself nicely in 3/4-power 230g 45 ACP rounds <-- you'd think that heavy slug would make it "spikey;" but it doesn't seem to. In fact, my chrono says it's an extremely consistent round.

To me, powder burn rate charts only exist to give one a ballpark starting point for their loads. Or to look for an alternative powder that my perform roughly the same, or intentionally slightly different. That sort of thing. And they perform that task sufficiently - in spite of the seeming contradictions.

[57K]

What's hard to follow?

The point is that Burn Rate charts are nothing but a guide for general consideration to begin with. Since we know the parameters in how they're placed, I don't have a problem with them being placed exactly how they burned in the closed bomb test by actual elapsed time of burn. Of course there are variables and their true order can change from one cartridge to another. I just don't see lumping a group different powders into a single burn rate category as helpful. That's what I mean by stereotyping powders.