22-243 Los development with rl26?

Ok I’m thinking of trying rl26 for my 22-243 with a 74 g bullet I had custom made. Now if I develop a good load at say 50-60 degrees how will it do at 0 and say 80 plus or should I look to something else for powder?

 

Only you can answer that question. Bust out the chronograph, and measure for yourself...

I ran RL-25 in my 22-243 for a spell, and figured 1.2 fps/°F change, based on doing just that. So, although I lost maybe 80fps between Summer & Winter, the POI change on target inside of 300yds, was negligible.

Also, many ballistic programs now have a 'temperature sensitivity' data point, where that value can be entered. So, everytime you shoot, simply enter in current conditions, and the program will solve for an adjusted muzzle velocity, from the original 'zero' conditions you already have saved. That is a great feature! And really makes temp stability less of a 'ballistic'. issue, than could be...

The MUCH more important aspect is to WATCH FOR PRESSURE in elevated temperatures!!! I try to 'load test' during the warm Summer months, to allow for a safety buffer, of sorts. When a load is deemed 'safe' when it's 90°F outside, worrying about a temp related pressure spike when the mercury drops, is essentially negated...

'26 will prolly be a good powder for your .22-243Win. But, I'd sooner try some '23, as I KNOW that RL-22 is an absolute rock star in that wildcat...

Good luck & be safe!