What are you shooting now? Rifle, scope, ammo?

Past 300 in a hunting situation or for targets?

And how far past 300?

Seeing a target at 600Y, especially with a VX3 shouldn't be a difficult proposition....BTW if the target becomes smaller when you scope it, it usually means the scope is mounted backward.

....but the biggest question, if hunting, is 'should you'? It takes a tremendous amount of skill and practice to be able to shoot game past 300, not so much when target shooting off a bench or prone.

To clarify: A 3x9 is enough to see the target but not enough to see if you are hitting it (at least if you're shooting paper). That may be your problem or perhaps the wind or other conditions. Also, it's doubtful you can 'shoot small' if you're shooting different loads in the same session. P_102

Yes, I should have clarified that too. I was referring to seeing where I am hitting.

So, I guess the next question would be is what is your recommended target for being able to see your hits at 400Y+

The number 1 thing bogging me down is being able to see. I can start to figure the other stuff out if I can see where I am hitting.

Absolutely. I have 3 different rifles that I can routinely shoot 2.5 - 3 inch groups at 600 yards when shooting off a bipod with a rear bag. But no way in hell am I shooting at a deer under field conditions at that range.

So, to answer the OP's original question, you need the right equipment and enough practice to be competent.

For equipment, I want a rifle that will shoot a long/heavy bullet at a fairly high velocity into 0.5 inches or smaller at 100 yards. Then you'll need a clear and durable scope with accurate adjustments and enough magnification to see your hits at whatever distance you're shooting.

Then you'll need to practice. And going out and shooting 10 rounds isn't really practice. Think more towards 50+ rounds in a session.

The GF shooting my 260 at 500 yards last Saturday. Her first time to shoot that far, and first time to shoot this rifle. She was getting 3.5 - 4 inch groups.

God Bless that girl...her form may be not what I'd call "perfect" and I could not hold that position for more than 10 seconds before my hamstrings and lower back would make me sit down for an hour...LUV the shoes and could not walk 10 feet in them across a pasture...much less go check the targets ...but if it works for her then it works and thats all that counts. She's INTO the task at hand successfully too. Well Done young lady....Well Done.
Ron