Toying with using my 110V action to build for long range.

My first thought is whats the biggest cartridge family that action will run when replacing the .223Rem bolt head?

What the biggest cartridge you can use would be your first question, not your first thought.
If you have a real 110 long action, then anything a staves Savage action length can handle. Check out the action length info in the FAQ section.

How can I have a question without thinking about it first? There are fake 110 long actions?

They ended in question marks, and asked a question, so they are questions. Thoughts don't need answered as they tell something, not ask.
Thought: I think crocodiles are angry cause all those teeth and no toothbrush.
Question: why are crocodiles angry?

My questioning the action is about age, read the FAQ I referenced. Unless this is an old rifle, a 110 (long action)isn't chambered in 223. That would be a 10 series.(short action)

308 would probably be the biggest normal. I am assuming its a short action despite the numbers (those exist oddly enough)

Short magnums would work as well but there seems to be issues with not working well in small shank.

I think 260 Remington is marginal but the short actions have a bit longer throw so that might be possible.

270s would be out as that is a 30-06 case necked down (pretty much)

110V with the stippled stock from the 70's, oem factory 26" barrel. Yes, it's a long action.

It was a gun very similar to the 110 Silhouette of the same era.

Pretty much sky is the limit then.

How far do you want to shoot and just for target?

The 6.5s are highly regarded distance wise but hunting you need heavier bullets.

You can add the magnums, that may get into the larger nut detail and issues as it does with the Short Magnums.

A 110V from the 70's would be a 110 short action.(4.522 screw spacing)

Aaannnd Sharpshooter would be correct. I've owned this thing for 3 decades or so and always thought it was a long action because of how small the .223 case is in that opening. I apologize guys, I stand corrected. And disappointed I don't have a long action to start with.

You might dimension the Remington 260 case or even get one of them in the Hornady bullet seater series and see if it cycles.

It might be a single loader with mag limitations and needed or desired COAL bullet lengths.

The short action is a bit longer than most,