That 12 twist will send 168s just fine.
The .308 was birthed with a 168gr bullet.You are both using heavier bullets. Would a lighter bullet like a 150 or 155 shoot flatter at long distance for a target round? I'm certainly not arguing, I'm just trying to get my thinking right.
Check out some of the smaller companies if you have trouble finding bullets. Maker and Hammer. Theymake excellent quality pure copper hunting bullets.
All the extreme long range does not apply to hunting with a 308 Win. A reasonable distance off the cuff with my 308 Win hunting would be about 375 yards of deer sized game. In the 178 ELDX look mostly at bullet performance at certain velocity ranges will dictate your max range and based on your shooting ability.I tried 150 grain in my lr308, and was not as happy with the accuracy as I am with the heavier bullets. I have not tried anything lighter than 165's in my other 308's. For what I am shooting, typically under 200 yards, I am not as concerned with potential differences in drop between a 150 and 178 grain pill. Realistically the 178 eldx for longer ranges will likely perform better anyway with a higher bc, and less likely to be influenced by any wind drift. Where the lighter pills have a higher muzzle velocity, they may not continue to carry it downrange as far as the heavier options. I have not input a 150 into a ballistic calculator to know at what point the heavier bullets are maintaining a higher velocity.
Also if you can find some 175 Berger Tactical OTM work excellent in 1/12 Twist .That 12 twist will send 168s just fine.
I used to use a lot of TAC because I could get it when everything else went missing. Good accuracy & consistent with a little work.FYI, Graf & Sons has H335 and TAC in stock. TAC is another good .308 powder.
Ramshot TAC Smokeless Powder 8 Pound - Graf & Sons
TAC is a double-base spherical propellant that sets the standard for extreme accuracy and reliability with heavy bullets in the 223 Remington and match applications in 308 Winchester. Excellent flow characteristics ensure consistent metering and charge weights for repeatable results with...www.grafs.com
Hodgdon H335 Smokeless Powder 1 Pound - Graf & Sons
This spherical powder originated as a military powder and is perfect for the 5.56 NATO/223 Remington. Multiple applications in the 222 Remington and other varmint cartridges. Prairie dog shooters will find this a favorite, as J.B. Hodgdon has for years!www.grafs.com
I have some WC844 that I've been using in .223 and it is outstanding. That stuff was dirt cheap back in the day. I may try a few rounds of .308 with it.If you plan on a lot of shooting over long term you can look for pull down military powder like WC846. Work that up slow and always start over when you start a new jug/batch.
I never used ball powder in 308 win except for factory loads 150gr Silvertip was always a favorite in 30/06 and 308 win for deer hunting. Pretty sure they used 748/760 in their factory loads. I always wanted to try 748 in 308 win.I've killed a bunch of deer and a few coyotes with 150 gr. Hornady Interlocks and Win. 748.
I never used ball powder in 308 win except for factory loads 150gr Silvertip was always a favorite in 30/06 and 308 win for deer hunting. Pretty sure they used 748/760 in their factory loads. I always wanted to try 748 in 308 win.
760 for 30-06748 is about the right burning rate for .308 but, in my opinion a little fast for .30-06 and similar long action calibers.