Which is faster burning?

I think Rl 25 is a little faster,will have to check to be sure.

Faster to slower:

210 Retumbo
211 H-870
212 AR-2214
213 RL-25

[ 12-01-2003, 09:02: Message edited by: ricciardelli ]

Steve. No way H870 is faster than RL 25...No WAY!

I've used RL 25, Retumbo and H870 in a 257 Wby ,a 7mmSTW and a 300 Rum.Of the 3 powders H870 is definitely the slowest. Retumbo is faster than H870 and RL25 is faster than Retumbo. IMR 7828 is faster than RL 25.

Hey, wadda I know? I've only used Retumbo in 78 different loadings, H-870 in 231 different loadings and RL-25 in 171 different loadings.

Evidently my experience is not as vast as yours...

Every data source that I know of lists RL25 to be slightly faster than Retumbo. H870 is definitely the slowest of the three.

Lee Martin
www.singleactions.com

. . . . that's what I love about those relative burning rate charts -- one never agrees with another and all of them have glaring discrepancies.

One fly in the ointment is that some powders behave much differently in one volume of case as opposed to another. For instance, some burning rate charts actually list Hodgdon 335 as SLOWER than BL-C2. In very small cases, H-335 does seem to burn slower than it does in larger cases, and it is true that in a case like the .223, there is very little difference in the buring rates of the two powders. But when the volume of the case increases to something larger, like the .375 H & H, BL-C2 is MUCH slower (as defined by the amount of powder that it takes to reach a particular pressure) than H-335.

I won't get into the Retumbo-RL25-H870 fight because I've never used either of the two newer powders, but I can tell you from many years of experience that H-870 is a tad slower than the old 5010, and that's s-l-o-w. Surplus WC 872 is slower still, and by a large margin (at least in the lots I have used).

I didn't take it personally...honest...

I just figured that your experiences with those powders might be more broad than mine.

As I state on my page with the rate chart:

"Approximate Powder Burning Rates From Fastest to Slowest

Now, before you even begin to look at this table, please note CAREFULLY the word "APPROXIMATE"!

I have spent the last 14 days compiling data from all reloading component manufacturers who have seen fit to release THEIR Relative Powder Burning Rates.

These guys can't agree on anything!

As a matter of fact, even the same manufacturer will change their data on a year-by-year-basis. So if they don't know what the hell they are doing, how should I?

The variation in "relative burning rates" varies not only by manufacturer, year and which way the wind is blowing, but also by the capacity of the case you are loading that powder in, the type of primer you are using, and the weight of bullet which is sitting on top of that primer and powder.

Not only that, but it also depends on how much powder you are loading.

Now add all that togther, and then confuse the matter even more because each lot number of the same powder, from the same manufacturer, will have a different burning rate!

So there you have it guys ..."

What I listed in my post concerning the burn rate of the mentioned powders is what I have experienced, with the firearms I used, in the calibers I loaded, and with the components I selected.

As they say at the bottom of all TV commercials, "Your results may vary".

FWIW--I only tried H870 once. It was so slow and dirty I couldn't believe it was on the market. Speeds I got were down almost 400 fps on some weatherby magnums from what the books said. I e-mailed Hogdon with my chrono results and nevergot a reply. It took me a while to "like" Hogdon again but I came back to them on certain applications. It was the only powder I saw fit to burn in my driveway---ps I think I even had a hard time lighting it with a match!!!!!!!!!!!!!

Pop,

RL25 will likely be 2-4 grains faster than Retumbo in the 300 Ultra, I've tested a few lots of each. H870 will be even slower by a few more I'm sure, I've not used it because it's temp sensitive tho.

I know of knowone that has found those powders rates in that order but Steve.

Even though RL25 is faster than Retumbo, I think you'll find Retumbo hammers cases harder at the even lower pressures than RL25 does, and MV will be better in the end with RL25, if case life matters to you. Don't ask me why Retumbo is like this tho, pressure vs time or something? I've not looked into it, but it's real in my rifles.

Retumbo has produced nice groups in both rifles tho. I'll be working with RL25 again because Retumbo is so hard on cases. I wonder if H50BMG, being slower yet, is even harder on them, or it's unique to Retumbo for some reason.

You should find good groups with RL25 or Retumbo at 90-94gr using the the 200 Accubond. You'll probably find less pressure signs at the same MV using RL25 tho. I get unhealthy pressure signs on cases with Retumbo at 62-63Kpsi, and only slight pressure signs at 69-70Kpsi using RL25 with the Oehler M43.

Thanx fellas!!!!!!!!!