Hey Fellas, I am the guy posting on Instagram about getting the 153's moving fast with (The screen shots that were posted in the first few posts of this thread)
I will tell you my current load is 45.5 of rl 26, 153 atips, Federal match mag primers. COAL of 2.950 26 inch barrel (Bolt action). They are moving at 2818FPS with single-digit sds and a half moa, and getting me half inch groups. I know that sounds fast, but I can assure you it is not overpressure. My Bolt will not let me go overpressure, and matching up with quick load data I basically can't go over 50,000 psi without having primer flow that pops the primer (I need to get my bolt bushed I can even load max with h4350 without this happening) . My primers are completely round, not flat at all, zero marks on the brass, the bolt is easy to lift etc.
I have tested the hell out of these rounds, but primarily with RL 26. I did a little testing with RL 16 and 17. Basically just a Satterlee on each and a group or two.
Rl17 best speed I got was 2743 at 42.2 Grains
Rl16 got me 2761 at 42.9gr!
Hope this helps, I do believe getting 2950 with rl26 at the 153s is very possible at safe preasure, there is just something different about the RL26, I guess its the slower burn rate!
Also note this is all with a barrel that has 4000 rounds through it, that being said my new barrel just came in today so back to load development!