Home Forums Reloading Big Game Rifles Pls help me understand high temps and increased pressure

Ya reckon we being trolled...??

LB is churning out definitive statements that are off the cuff, many over the edge. RL-23 IS a temp stable powder, NOT a sub for RL-26, two different burn rates. He's the only one I've seen declaring RL-26 to be one of the most temp sensitive powders ever. Facts just don't back that up.

Don't think LB has shot much TAC (maybe not much of anything else). Looks like he's reading stuff off the internet, pontificating about stuff he obviously can't authenticate.

Oh well, This is the Fire, after all...

DF

Yeah, Larry Root has come to mind several times as I’ve read LB’s posts...

I dont get it. The guy said he tested the powder with far more specific equipment than I have access too. Are you saying he didn't, in fact test it or that his results are wrong? Or do you think he's wrong because his experience is different than yours? He doesnt seem to be the only one who experienced velocity/pressure spikes with this powder. I understand you and other members havent seen it but does that mean his experience is invalid?

In science, any marked outlier in data, even measured data, is suspect until proven otherwise.

If those cases, means and methods need to be thoroughly reviewed and analyzed.

LB's overall credibility and his outlandish claims puts his "highly technical and carefully measured data" in that category.

In the meantime, I'm going with Jordan, JB and others with credibility proven over the long haul

If wrong, I'm certainly open to review of facts and conclusions, as I continue to work up 7RM, 160 NAB, RL-26 loads for my buds African PG hunt in August..

DF

Apparently this thread brought out all the clowns who think non-temp-stabilized double base powders aren't temp sensitive.

I suppose it's possible that the laws of chemistry were repealed specifically in your rifles, and powders with the least temp stable chemistry in common use (we don't do triple base powders and cordite any more) are somehow stable for you. If so that's great.

But reality is that there's a hierarchy in terms of powder stability by chemistry from most stable to least:

Temp stabilized powders (recent ADI series, IMR Enduron, and the RL-16/23/AR-COMP series)
then
Single based IMR-type powders
then
Double base not temp stabilized (which includes the RL series with the exception of 23 and 16, TAC, and a bunch of other powders like H335 etc.)
then
Triple base powders, cordite, and certain other obsolete powders

There's really not all that much to it, but of course lots of marketing chaff being blown by companies with an interest in selling non-stabilized powders. In the end I don't give a flying [bleep] what you put in your rifle, but the facts are the facts.

See Dirtfarmer's response above.

I don't have a problem with other people having legitimate experience which runs counter to my own, but I always consider the source of any such info. Some sources of info have earned more credibility, and are more deserving of trust, than others. In this case, LB has posted enough non-sense in other threads that his "experience and measurements" are suspect. I question whether he personally has tested RL26 at all, or is just regurgitating something he found on the internet, as with most of his other posts.

+1

Some of us don't have to pontificate about the theoretical behaviour of these things, because we've actually tested them in a variety of circumstances. We KNOW that certain powders are temp-stable in a wide range of applications, despite what your assumptions or Google results may say.



In the end theory is theory, and facts are borne in experimental results.

Them some nice clown shoes ya'll are wearing.

Now, explain why chemistry works one way in my rifle, every other rifle, and the chemistry lab, but DIFFERENT in a couple people's rifles. You could imagine that I, the lab, the chem books etc. are all in error. You could imagine those couple rifles are magic. Or you could imagine that a couple of people who lack temperature chambers and just guessed their way through it made errors. It's up to you. I really don't care what the [bleep] you shoot. But realize that chemistry is chemistry, and no amount of backslapping and clown show wearing on a forum will change that

There's a REASON none of these double base non-stabilized powders are used in accuracy disciplines any more - because they're not stable That's why you almost can't buy an 8-lb keg of H4350 or RL-16, but there's all the RL-26 you want to buy waiting there for just he right sucker to come along

Good thing I've got far more experimental results than you. Call me when you're using a temp chamber rather than clown shoes to heat and cool your rounds

Also, if you knew jack [bleep] about propellant chemistry you'd know the "theory" on this is old, well understood, and really not up for debate This is almost 100 year old news we're talking about here

You clearly don't even know what you don't know.

What chemistry labs? What chem books? Perhaps you don't realize that temp-stability of ALL powders is dependent on the suitability of the application to the burn rate of the powder. Some powders are more sensitive to this than others, but all are affected. Even if you did test RL26 (which I doubt) in one rifle, using one or two bullets, that is a far cry from sufficient experimental results to come to a general conclusion with any validity. Yes, there are a couple of other people who have experienced temp-dependent velocity variation using RL26 in a particular application, but the majority of credible sources have reported the opposite, at least below 90 degrees.

There are far too many internal ballistics variables at play in a given rifle/cartridge sample for you to make a blanket statement about "chemistry is chemistry", and have anyone with half a clue believe that you know what you're talking about.

In the last few months RL26 has been far harder to find than H4350....

Then post them.

Yes, I can Google "temp chamber" too.

I hear reports of RL-26 being hard to find, so where is LB seeing all this RL-26 for sale?

If he would be so kind to reveal those sources, many here on the Fire would be very grateful

DF

The reason that we lose velocity in cold weather is that cold steel, lead, and brass rob heat energy from the propellant gas more than hot metals do.

Temperature insensitive powders compensate for this by burning a little faster than other powders when pressures are lower. This offsets the loss in MV.

In the cases I've tested, temperature compensation only works really well in a particular case geometry. For example, Varget is wonderfully stable in the 308, but not stable at all in the 223. H4350 seems to be optimized for stability in the 30-06.

Precisely. The temp-stability of a given powder is dependent on the application. Bore volume to powder volume ratio, bullet weight to powder volume ratio, etc, are factors in a given application that affect the stability of the powder in question.

Which makes all encompassing, overly broad statement of "fact" not factual...

Experience leads to caution, the lack there of tends to lead in the opposite direction.

Not too hard to spot the difference.

DF

denton,

All excellent points--which the head guys at more than one professional labs have mentioned to me more than once.

Even the most temp-resistant powders don't work as consistently outside their design parameters, which one of the guys who's been working in the business for around 40 years also called their "comfort zone."

The .264 Winchester Magnum with 100-grain bullets and Reloder 26 would obviously be outside those design parameters, but LB cites it as his primary example of the abject failure of 26. Which he also tested in an indoor lab, without the rifle at the same temperature as the ammo.

I have tested 26 with the 150-grain Nosler Partition in the .270 Winchester outdoors, at temperatures from -10 to 90, one of 26's definite comfort zones, in fact one of the combinations it initially became known for. The variation in average muzzle velocity was 45 fps, .45 fps per degree. Point of impact never varied.

But of course LB will tell us that the testing was faulty, because he got different results firing 100-grain bullets indoors from a .264.

Funny you should ask that, because if you knew jack [bleep] about propellant chemistry, you'd know that temp stability and nitroglycerin content has been an issue all the way back to Alfred Nobel trying to pawn Ballistite off on the French government in the 1880s. They were't as foolish as he'd hoped, spotted the stability problem, and stuck with the single base nitrocelulose Poudre B and thus got the first working smokeless cartridge. The Italians were more gullible and bought Nobel's mistake and lost 5 years jacking around with it until they invented Solenite which is still laughably unstable by modern standards but at least could be used.

So the role of nitroglycerin content has been understood for right at about 130 years now. Except by you. I guess some subjects just aren't covered in clown college

How'd you come to that conclusion? Provide calculations please.