I've never hunted in Texas but it's common to have specific calibers like the .223 prohibited as deer hunting rounds. It would be wise to check for sure.
On your bullet selection, 77 grain is a heavy bullet for .223. A 1:7 barrel twist may be needed for that bullet. I shot 69 grain bullets in a 1:8 twist with good results.
Sierra Match Kings are hollow points but they are not recommended for hunting.
Flash
Which rifle/barrel is it? Is the chamber actually .223, or is it 5.56? As Roger implied, I don't think you're gonna get the accuracy you want with anything above 55gr.
chambered for 5.56 with 1:9 twist. most of the reviews of the rifle suggest that it wants slightly heavier bullets. shooting .223 53gr VMAX has only gotten me 1 MOA of accuracy.
Have you tried any premium ammo in 5.56? Generally speaking. .223 ammo will be less accurate from a 5.56 chamber than 5.56 ammo.
I would think that 1moa would be accurate enough to take any varmint out to the effective range of the .223.
I have shot many crows and groundhogs with a rifle that would do about 1moa.
I think that most of the 1/2 moa groups people talk about on the forums were shot with the keyboard.
Maybe it's just a 1 moa rifle.
good?
I think limiting to 55gr is a bit of a stretch, bout I seriously doubt there is any possibility of stabilizing a 77gr MK out of a 1/9 twist. I would test up to 62gr, but varmint rounds tend to be longer because of the cavity.
A lot of ballistic tips because the material is lighter than lead. I'm not saying they all are, many varmint rounds are stubby and more blunt faced with a large cavity, but with the popularity of long range varmint hunting more bullets are coming out with Higher BCs as a goal which can and many times does equal "long for weight" bullets.
Still don't really think a 55gr would be stretched to a length that 1/9 couldn't handle. Just not enough to work with.
True most "varmint" labeled bullets aren't that long the 1:9 won't stabilize it. It could be the rifle just doesn't like the particular bullet which happens at times.