Retumbo - Powder temp V's velocity

[Topshot]

Has anyone got any data on the effect temperature has on Retumbo powder with regards to muzzle velocity?

My chronograph is a bit unreliable so I am looking for some help.

Just want to get a feel for how sensitive this powder is to changes in temperature and to what effect. Faster, slower, magnitude?

Also any info on H1000 would be great as well.

Thanks

 

[Greyfox]

I have done some work with my 6.5x284 loaded with 140vld's and 59 gr of Retumbo. My Chrono tests seem to indicate a 15-25 fps velocity difference from 25F to 80F. I am not completely confident of chrono data especially when testing on a 25F day and comparing to data aquired back when it was 80F. But, this appears to correlate well when I plug my baseline data into my ballistic program and do some actual field testing at extended ranges at the actual temperatures. Bottom line is that I get pretty close when I plug temperature changes into my ballistic program. Just my experience.

 

[chad44]

Hogden claims that any powder with extreme on it won't be effected by temp. Both those powders are labeled as extreme. I have not tested this but I've seen guys online test it by using a cooler to freeze some rounds on a hot day and their test showed no difference. It was the guy from long range pursuit tv show.

 

[midnightmalloy]

Go to longrangepursuit.com and in there tech or do it yourself section there is a test of this you can watch. Prettygood stuff.

 

[Topshot]

I contacted ADI who make this stuff. This is the reply that I got below, for what it is worth.
I do know that they test in 24 inch barrels so that may have some effect?
My results with my rifle seem to indicate a change of 25 fps so this is within the range that they state but over a smaller temperature range.

It is interesting to see that they start their testing at -0 degrees. Strange things happen at the freezing point of water so a step change at this temperature might also be possible?

Looks like more testing required with my rifles.

*************************************************************

Thank you for your enquiry of 7/12/2011 with regard to reloading using ADI Sporting
powders.
ADI propellants have a built-in technology which provides superb ballistic thermal
insensitivity. The change in velocity over the temperature range of -0°C to 50°C is
generally less than 30 fps. Unfortunately, we have no data measured in the particular
firearms you mention: we perform our testing using test barrels in a controlled,
laboratory environment. The components used will also effect the ballistic thermal
insensitivity.
Extreme caution should be taken and loads should be worked up accordingly. Refer to
our website at www.adi-powders.com.au or our 5th edition handloaders' guide for more
information, warnings and reloading safety.​

We thank you for using ADI Sporting Powders.