Will do.
If we are taking gambling off the table, I think 500 yards is a stretch. At my altitude the 77 TMK is going to be about a 4MPH cartridge. At least in field conditions, a lot of people are going to be hard pressed to call wind speed better than 4MPH (and we are completely ignoring direction), which means you have a +/- 0.5 mils to add on either side of your ability to shoot. So add 18" of width to your ability. If you can shoot 0 MOA groups, you are already gambling on most big game animals. If you are able to perfectly call the wind direction and can be within 2 MPH of speed, we are still talking about 9" of horizontal variance, so you need to be able to shoot about 5/8 MOA (accuracy) on demand, which would correlate to groups (precision) in the 3/8 MOA realm (or likely smaller).
Let's say you only ever shoot from the prone, and you consistently shoot 0.5 MOA (precision), which will likely translate to 0.625 - 1.0+ MOA groups (accuracy) at distance. AND, let's also say that you are an "elite" wind caller in field conditions and can call the wind to +/-2 MPH (speed) and +/- 30 min (direction). At 350 yards, you are looking at about 3.5" of shooter variance, and +/- 2.2" from wind speed. In 10+ MPH winds, you could have an additional directional error of 2.5+ MPH (depending on actual direction), which would be +/- 2.8"+. So we're talking 13.5"+ of total horizontal variance assuming you are able to dictate position. Unless you venture into the probability game, I think most people will be looking at the 200 - 300 yard range as their maximum effective range with a 223 (any position and unknown conditions). You very well could be an outlier though, or the statistics just haven't caught up to you.
By simply choosing a better/more efficient cartridge, you can easily extend your effective range. Generally the trade of is ability to manage recoil, which is a basic/fundamental skill IMO. My 7RM is about an 8MPH gun at my altitude. The unknowns associated with the wind variance are cut in half, which will significantly extend your effective range.
I'm making a small transition this year.
1) heavyweight/heavy use custom steel action, steel barrel, ZCO optic, chassis. Currently chambered in 6CM, and will likely be chambered in a 6mm or 6.5 variant moving forward (depending on availability/cost). Atlas gen 2 bipod, TBAC Gen 1 6.5 Ultra 7.
2) midweight/medium use custom steel action, current barrel is about burnt out and I'm debating steel vs CF wrapped barrel for the next one, currently has a ZCO on it, carbon fiber stock. Currently chambered in 6.5CM, and will likely be chambered in 6mm or 6.5 variant moving forward (depending on availability/cost). Atlas gen 2 bipod, TBAC Gen 1 Ultra 7 30 cal.
3) Light(ish) weight primary hunting rifle custom Ti action, carbon fiber wrapped barrel, carbon fiber stock, Tangent Theta, chambered in 7mm Rem Mag. Atlas gen 2 bipod, TBAC Gen2 Ultra 7 30 cal.
The ZCO on #2 might make its way to a Vudoo 22lr build, and I might replace it with a baby ATACR on #2. Maybe. I have a couple other stragglers that are either sentimental or not even worth selling or something that I'd gift or give a good deal to someone local that I know, but those 3 listed easily get 95% of my time. Moving forward, I might sell a stock/chassis or optic or something to fund a replacement, but I don't really care to expand that set-up.
'Do what you have to do until you can do what you want to do'