Alliant reloader 17 is a really good powder using the 100 grain bullets in .243.
It's not temperature sensitive and meters well.
IMR 4350 is an old standard that works in larger calibers too with heavier bullets.
There are several different powders out there that can do the job, but I recently switched the .243WSSM, 30-06 and .270 to the Reloader 17.
It is billed by the manufacturer to give 100 additional FPS with no increase in chamber pressure. Which drives me to add a little more to increase speed.
Take this advice to heart. If you don't have a Chronograph, DO NOT exceed factory recommended loads. When you do buy a chrono and get your bullet speeds and can watch the variances between powders/temperatures, Then you can creep up in speeds and recognize the first signs of overpressure that will be the primer going flat.
Reloading has a huge learning curve. Some do it wrong and jump into it.
Your doing it right by asking really good questions.
It's not temperature sensitive and meters well.
IMR 4350 is an old standard that works in larger calibers too with heavier bullets.
There are several different powders out there that can do the job, but I recently switched the .243WSSM, 30-06 and .270 to the Reloader 17.
It is billed by the manufacturer to give 100 additional FPS with no increase in chamber pressure. Which drives me to add a little more to increase speed.
Take this advice to heart. If you don't have a Chronograph, DO NOT exceed factory recommended loads. When you do buy a chrono and get your bullet speeds and can watch the variances between powders/temperatures, Then you can creep up in speeds and recognize the first signs of overpressure that will be the primer going flat.
Reloading has a huge learning curve. Some do it wrong and jump into it.
Your doing it right by asking really good questions.