Looking for poowder that is not heat sensitive
Have a 223 rem 30" barrel shooting 90gr beregrs
Was using VT 550 but no more available in Canada and I am concerned about heat with double base powders. Varget gets me to 2820fps a little slow can get over 2900 with 550 with no pressure,in cool weather good accuracy. what powders would you try that 's not heat sensitive
My friend was shooting RL 15 24.3gr very good accuracy but at shoot at Connaught May 22 Temp hit 90 + he had pressure problems, loose primers and leaking.Tryed H 4895 not enough speed mid 2700fps,have some Hybrid 100V ???
any help would be nice
manitou
and he had pressure problems,

You might want to look at RL-10.

I've used RL-7 a lot but that was with 40 grain bullets. It's proven to get me the accuracy and velocity that I was looking for that Varget couldn't offer.

Assuming you are shooting a bolt gun not a gas gun.

2820 with Varget is pretty good, and does not seem be too temperature sensitive. 90 degrees is a cool day down here.

Anyway, after shooting thousands of 80 grain SMK out of my 28" barrel ARs, RL15 or Varget has always worked well.

I have been doing a little research thinking about trying the 90 grain bullet. 24 grains (start lower) of H414 (slower than 540) may be one to try. Hopefully somebody could chime in on temp sensitivity of H414.

RL10 may be a little fast for the big bullets.

Good luck, let us know what works.

I have used Vihta-Vuori N140 and N540. Also used some IMR 4895 with Sierra's 90 grain bullet.
I never got any where near the velocity you mention. I was getting between 2500 and 2600 fps. And I don't think the extra barrel length you have(mine is 24 inches) will help that much.
Good luck with your search.
PS I am not familiar with the VT500 series of powders. Is it possible to find some in the states?

muck

Doubtful you're going to get faster than these . I don't use anything over 75 gr. in my .223's so no experience

with heavier bullets .

Bullet Powder Charge FPS OAL Loading person

Berger 90-gr. VLD Reloder 15 22.0 2611 2.635 L. Simpson
Berger 90-gr. VLD VV N-550 23.0 2574 2.635 L. Simpson
Berger 90-gr. VLD IMR-4320 22.0 2561 2.635 L. Simpson
Sierra 90-gr. MatchKing H4895 21.7 2600 2.550 Sierra
Sierra 90-gr. MatchKing IMR-4064 22.4 2600 2.550 Sierra