too hasty
Much ado about nothing. A .308/150 is a classic deer load, I'd think more than enough for a TX whitetails and hogs, irregardless of barrel length/velocity or lack of it. The OP claims to have shot 3 animals, recovered two, and the third may or may not have been a hit, and may not have been a good hit.
The next three may drop on the spot, with or without exit wounds. How dead does the deer need to be?
Bamaboy and I each killed a mature buck last season with the .308 Hog Rifle and 1st generation 180 gr Nosler B-tips. Slightly quartering shots, and neither yielded an exit, we recovered both bullets. Both deer went 10-20 yds before piling up. We care not a bit. We shot the 180's cause the rifle likes'em, and I traded for a couple of hundred. Also have had good luck with Sierra flat base 150's, from two other rifles, and one of those has a stubby barrel too.
If you've lost confidence in the load, why not change if that might boost confidence, but I'm claiming any 150, cup and core bullet from a .308 will work for you, just give it a chance.