Single digit SD’s

[diggler1833]

I’m finally there with my hot weather load for my 6.5cm. I had to back down .5 grains of H4350 on my go to 600yd load to get me back into the node when air temps are above 95 degrees. I did my load development when it was 68 degrees, and my groups open up and gained roughly 60fps with this load when it’s over 100 degrees outside.

I finally have two solid loads, needless to say I’m learning!

-41.2gr of H4350
-140gr ELD-M
-2.210 CBTO
-24in barrel

Crap. I totally forgot to ask if you had switched primers during your testing?

 

[swampratt]

I went and filled a R-P case in 6.5 Creedmoor with newer H4350 41.2 gr.
The small granular stuff. Not the old grey colored stick stuff.

That powder was at the bottom of the shoulder

 

[diggler1833]

I went and filled a R-P case in 6.5 Creedmoor with newer H4350 41.2 gr.
The small granular stuff. Not the old grey colored stick stuff.

That powder was at the bottom of the shoulder

That'll just about guarantee a crunch unless you have a factory Remington throat and load to the lands .

 

[swampratt]

That'll just about guarantee a crunch unless you have a factory Remington throat and load to the lands .

You are correct.

I looked at my 140 A-Max 6.5 load and the boat tail is below the shoulder by a tiny bit and that is loaded to 2.808" I run 41.4 gr H4350.

I have a Savage rifle and Neck turned makes a difference in group size for the better.
Many trips to the range testing annealed vs not and neck turned vs not.

 

[BallisticGuy]

Crap. I totally forgot to ask if you had switched primers during your testing?

Same primers. I still need to shoot a string for MV-Temp data before it cools off so I can compare the velocity data to cooler weather vs actual cartridge temp. I’ll start logging data between my two loads to see if something different is going on as it cools off.

 

[diggler1833]

Same primers. I still need to shoot a string for MV-Temp data before it cools off so I can compare the velocity data to cooler weather vs actual cartridge temp. I’ll start logging data between my two loads to see if something different is going on as it cools off.

I've got three loads for the rifle I posted the groups photo of. All three were developed in 85+ degree weather, so I'm going to do the same as you and test them in 40 degree weather this winter after deer season.

It should make for some interesting data points.

I'm using Varget, H4350, and Reloader 15 in mine. I expect a huge swing in velocity with the Reloader 15...we'll see what happens to the group size.

Thanks for the reply on the primer usage. Good luck this winter.

 

[BallisticGuy]

I've got three loads for the rifle I posted the groups photo of. All three were developed in 85+ degree weather, so I'm going to do the same as you and test them in 40 degree weather this winter after deer season.

It should make for some interesting data points.

I'm using Varget, H4350, and Reloader 15 in mine. I expect a huge swing in velocity with the Reloader 15...we'll see what happens to the group size.

Thanks for the reply on the primer usage. Good luck this winter.

We’ll try to keep this post alive. I think another major issue I’m dealing with is my ammunition and barrel are already 140+ degrees when I go to shoot in the evening after baking in the heat. I honestly think this is a major player, and that’s why I need to gather MV-Temp data.