According to Sierra it's doable with at least two powders in a 24 inch barrel. Do these numbers seem outlandish to you or something?
No, I'm asking what powders you're using to achieve 2800fps
I'm at 2550fps in a 20" barrel at the highest load I've tried so far with IMR4895. Just curious
 
My NULA will push 150 grain Hornady flat base SP to 2950 out of a 20" barrel using IMR 4895. It will push a 130 TSX at 3150 with the same powder. Both loads are quite a ways below published max charge but since they are hitting max velcoity I stopped there. No pressure signs on either load, even at 90 F and I usually hunt at 0 or colder. The two loads hit within a half inch elevation of each other at -10 F, exact same horizontal, all the way to 400 yards.
 
Gr- what ammo did you ude? how about garrett what rifle/caliber anno did he like? thanks ron
 
Well first off I would recommend an 18 to 20 inch barrel. Also, I have tested 308 ammo for many years and have found the 165 grain and 168 grain boat tail soft point spear point works the best in just about any 308 cartridge. I don't buy much 308 ammo, I reload and have had very good performance with Hornnady 168 grain boat tail hollow point bullets loaded to 2800 F.P.S. out to 600 yards. When in the service we shot this weight bullet out to 900 meters very accurately. Just my opinion but I'm sure there will be others.
I agree, as a point of reference…I get average 2460 fps with factory 168 gr out of my .308 cross.
 
Great thanks
Just realized I really didn't answer your question. I was basically extrapolating. Bryan Litz shared an equation on the PRS blog that allows you to estimate velocities when subbing in different bullet weights.

V2 = V1*(B1/B2)^0.5 so V2 in this case would be a 165 and B1 is 185 gr and V1 is 2585. From my 20" barrel you'd get an estimated equivalent velocity at 2737 ft/sec. A 150 should hit ~2850 from a 20" barrel and a 165 would likely need a 22-24" barrel to break 2800
 
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