Quote Originally Posted by BoilerUp View Post
I don't have any data for heavies out of my SBR, but IIRC CFE223 can get wonky with pressure spikes with heavies, e.g., just a small increase in charge will give you a lot more velocity but you can get to unsafe pressures pretty quickly. RL15, H4064 and H4895 might give you a bit more velocity but are all stick powders, if that matters.
I am doing a lot of testing and plan on doing some more. I don't really care if it's a stick powder or not. Of the powders you mentioned H4895 is definitely now on my short list. It's #94 on the burn rate chart, but also published data shows it giving high velocities.

I will make a list of candidates and get 4 or 5 of them at a time to test (budget permitting).

I am not concerned with pure accuracy or anything like that. I am shooting it out of a 10.5" barrel with an Aimpoint T2. I am simply trying to get the best velocity out of that platform. 150 fps (or more) makes a difference when talking about terminal performance.

I don't know if you have seen this (old) video but look at the velocities he's getting. They are substantially lower out of a similar platform using factory ammo. His average out of a 10" 5.56 upper using Hornady SBR 75 grain ammo is only 2271 fps. Out of an 11" gun he's getting 2320. Just with what I have done so far I am beating both of those numbers by a substantial margin. My averages just using TAC beat those velocities from a similar barrel length by over 180 fps. Even out of his 11" barrel I am beating it by over 130fps using a shorter barrel length.