Reducing charges as Temp goes up

[chipdog4]

At 70*F and below, 48.0 gr of H380 shoots great from my Rem 308 Tactical. 80* and above, the group size doubles.

Is there a general rule of thumb to reduce by x% every so many degrees?

 

[427Cobra]

Re: Reducing charges as Temp goes up

Why don't you find a different powder, RL15 or Varget come to mind with 155-190's

 

[chipdog4]

Re: Reducing charges as Temp goes up

You're right.
I'll use this load when the temps are cooler and I'll work a new one with RL15.

 

[BCP]

Re: Reducing charges as Temp goes up

Drop it a grain or two and try again, I bet it'll be fine. Unless you want to switch powders in which case Varget is probably the way to go for temp sensitivity if you can get it.

 

[42769vette]

Re: Reducing charges as Temp goes up

i usto use 414 in someof my rifles. i did load development at 85 degrees and found a good load. this winter i saw a coyote and hadn't shot this rifle in awhile. i shoot quite a bit low and ran a second shot through a crono and i was about 70fps slow

 

[Unsichtbar]

Re: Reducing charges as Temp goes up

RL 15 in .308 rises and lowers in velocity about. .7 fps per degree from 75 F zero. When running 46.1 RL 15 .308 155 Lapua which is a warm load in my tight chamber, above 90F its is hard on cases.

After years of shooting RL15 and Varget switched to imr 8208xbr temp. stable, meters great, not hard on cases, lot to lot consistant, low es & sd could not be happier.