Opinions...

So I built me a new hog rifle, 300 blk out. What do you guys prefer Red dot or 1-4x scope? I will be using a green kill light, will the red dot show up at night with a green light?

So much depends on the reticle in the optical scope vs the visual quality of the red dot. My experience is that neither one is "better" than the other in any general sense, but you will **prefer** one to the other, usually quite significantly. Unfortunately, this is a question that you will have to answer for yourself.

My personal opinion, not to be confused as fact, is that for shots up to around 60 yards a red dot sight is fine. Somewhere beyond that you start wanting some magnification. In my case, I use an EOTech 512 sight with a 3X magnifier behind it. For me, that combination works up to about 100-125 yards, maybe slightly further. A 1-4X scope may be an acceptable alternative but I've never used one.

As for visibility using green light, I have no knowledge on that topic.
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I have 3 hog baits set with white, green, and red motion sensor lights as kind of an expirement. (I'll post results later this year) I use a Bushnell Banner Dusk and Dawn 1.5-4x. It has an illuminated or black reticle. You turn the knob one way it's green, the other way it's red, in the middle it's a non-illuminated black reticle. I can see the black in any of the three lights and the green and red can get bright enough to see in their like feeder light colors. Not a fan of red dots for hunting, at least in my experience, if the dot is of usable size and brightness it seems to cover too much of the target area for my personal taste. I went with this scope because it's relatively inexpensive and I could get the red, green, and non-illuminated black reticles all in one scope on one rifle.

Edited to add: Oh yeah, I have it mounted on a .308 Ruger GS Scout, mounted traditionally over the action.

If you're hunting a feeder put solar pathway lights on the feeder legs and the 1-4 will work better than the red dot.

1x4 or 2x7. It's difficult to put one in their ear when the dot covers their head.

I use a 2x fixed scope. Sighted it at 50yds 'cause almost all of my hunting is in that range(I stalk in the brush) and the crosshairs cover to much of the hog when hunting farther.