Anybody know a temperature stable powder with a similar burn rate as Retumbo

[mtbfarms]

Yes I can calculate for different velocities at different temps, but I am a rookie at this long range hunting and my target (whitetail) don't give me much time to do many extra steps before taking a shot.

 

[edge]

There is a powder chamber that is larger than the bore.
I have some h1000 on order. It tested about the same pressure as retumbo with a little higher velocity.

Do you know the dimensions of the chamber, or at least how much Retumbo powder it holds?

Is there a bullet stop above the chamber so it does not need to be 100% fill or do you always go for 100%?

Someone more knowledgeable than I could probably run Quickload if they knew the dimensions and get a good list of powders.

Mind sharing the charge you are currently using, and the measured pressure?
The more info known the better the prediction with something like quickload.

edge.

PS as I mentioned above, a 60fps variance if accurate is not anything to worry about...IMO.

 

[edge]

Yes I can calculate for different velocities at different temps, but I am a rookie at this long range hunting and my target (whitetail) don't give me much time to do many extra steps before taking a shot.

There really would be no extra time.

You have a range card for your hunting conditions anyway so the range card would be for the velocity too!

You can't use a BC of say 0.400 at 80 degrees and use the same 0.400 BC at 25 degrees!

Take a 0.400 BC at 80 degrees and standard pressure you might use around a 0.415 and at 25 degrees you would be more like 0.375

Since you have to adjust anyway I would be much more concerned with accuracy and an actual drop chart than the raw numbers.

edge.

 

[Catfur]

Is it possible, since you are shooting a muzzle loader, that at higher temps, the barrel expands, allowing more gas to escape around the bullet?

 

[Greyfox]

I agree with prior posts that something may not be right with your data. I have used Retumbo in a few calibers and found no issues with temperature stability. H1000 is close to Retumbo, and had also been temperature stable for me. H1000 in 30-06 through 338 Lapua sized cases appears slightly faster than Retumbo and with similiar charges will exhibit pressure signs sooner at maximum charges and generate lower maximum velocities. In the case of my 338, 2725FPS for H1000 and 2775 for Retumbo, all other components being equal.