Powder Flame Temp Test: An Experiment

[DoneNOut]

26" Benchmark barrel
708 virgin Lapua brass
162 ELDM
215M primer
Ambient temp 85 F.

Shooting conditions in shade.
Laser thermal hand held unit.
Measured temp within 2 seconds at end of string of fire. (Pointed at throat area)
Strings shot 15 seconds ave per shot.
Barrel cooled to 81 F. prior to each string of fire.
Powders used:
Hodgdon H100V quick load flame temp: 3545. (Ave MV: 2780fps)
RL17 quick load flame temp: 3990 (Ave MV: 2812fps)

Flame temp chart:

5 degrees F. difference between the two powders. Discuss…

 

[2buffalo]

Did you get Temps on outside of barrel or inside?

 

[DoneNOut]

Did you get Temps on outside of barrel or inside?

Outside

 

[2buffalo]

I would be more interested in the throat temperature. Seems like it would tell you more. I can tell you the temperature on my rifle barrels is significantly higher with N570 as it is with H1000 on three shot strings.

 

[MagnumManiac]

You do realise these heat numbers are taken from calorimeter tests, not inside barrels?
There is a real and definite difference. The only answer to this is: it depends on what cartridge the powder is being used in.

Cheers.

 

[Seabeeken]

I can tell you the temperature on my rifle barrels is significantly higher with N570 as it is with H1000 on three shot strings.

Double base vs single base powder

 

[ButterBean]

Well that's interesting!

 

[DoneNOut]

I would be more interested in the throat temperature. Seems like it would tell you more. I can tell you the temperature on my rifle barrels is significantly higher with N570 as it is with H1000 on three shot strings.

I got the hottest readings on both at the throat area, but from the top of the outside barrels. Heat transfers. So it only stands to reason if something was 500 degrees hotter it would show on the outside relative to the 500 degrees cooler burning powder. Instead, I got 5 degrees...

 

[Mark37082]

The temps were at least taken using the same conditions and demonstrate the relative difference in the powders. The cumulative effect over many firings has to impact barrel life. The minimal velocity gain may not be worth it, but the impact on barrel harmonics and accuracy would be my determining factor.
Thanks for sharing.

 

[MagnumManiac]

The temps were at least taken using the same conditions and demonstrate the relative difference in the powders. The cumulative effect over many firings has to impact barrel life. The minimal velocity gain may not be worth it, but the impact on barrel harmonics and accuracy would be my determining factor.
Thanks for sharing.

Really? Have you ever tried to get ANY calorimeter bomb information through freedom of information act? It is not possible because they, the powder makers, will not release the information because it comes under espionage intellectual law.
I worked for ADI, the company that makes the powders you know as Hodgdon Extreme powders and others. I worked in both powder manufacturing and the ballistics lab, even I couldn't peruse the results of ANY calorimeter tests done. All I was told was the batch number and whether or not the latest batch matched canister powder or bulk.
No company shares this information, no company even lists HOW MUCH powder is used in each test…so how is this relative to different powder manufacturers? More or less powder will give differing heat ranges.
Also, regarding powder heat and RQ (relative quickness) numbers, there is no standard that each powder is rated against. Each company relegates their own powder as the control. For instance, IMR has always used 4895 as their base range with RQ 100 and every other powder is then rated with a lower number for faster burning and higher number for slower burning. It just so happens that ADI has always used RQ 100 for AR2206H, which is the same as H4895…this is solely coincidence, no collaboration has ever been entered between them.
Other than those above, I have never been able to find the same information for Hercules/Alliant, Winchester, Vhit or Accurate.
How QL gets this information has me stumped, because I have tried. I can't even get SAAMI reference proof load information…this would be very helpful to me, but not being a member restricts your access. I know the parameters of a proof load, that being a load that is 20% higher pressure as a NORMAL load…what is a NORMAL load?

Anyway, I take all this information, both heat range and burn rate, as hearsay.

Cheers.

 

[Bob Wright]

That extra heat in RE17 is certainly showing up at .5° F more per trigger pull in this experiment.
Doesn't sound like much. But the inside surfaces see 3990°F for a few less milliseconds (bullet speed is faster). There is more heat going on with RE17 at the interior surface that only shows 5° more on the outside.
If I go with Hodgdon powders versus Reloder powders in the same manual for one cartridge, Hodgdon runs slower in all my chamberings and will pressure out quicker in speed tests versus Reloder. Not that it's bad but it's significant in speed.

 

[MagnumManiac]

Double base powders release more energy per grain burnt…this causes more heat, BUT, without a true way to measure heat directly inside the barrel at the case mouth, we do not know the time that that extra heat is generated. It is perfectly feasible that the heat from a double base powder could be less than that of a single base…the higher velocity is caused by the extra gas released by double base powder, not the pressure.

Cheers.

 

[joseph singleton]

WOW ,,LOVE this site ,info,info,info,,,,beyond my pay grade...Really splitting hairs..Hats off too ya on your efforts ..

 

[Bob Wright]

Double base powders release more energy per grain burnt…this causes more heat, BUT, without a true way to measure heat directly inside the barrel at the case mouth, we do not know the time that that extra heat is generated. It is perfectly feasible that the heat from a double base powder could be less than that of a single base…the higher velocity is caused by the extra gas released by double base powder, not the pressure.

Cheers.

Isn't the extra gas more pressure?
I agree that the heat generated 'may' only be figured out by mathematically backing into temperature in the chamber/barrel.