7.62x51 vs .308 Case capacity for reloading

I am in the process of trying to replicate M80 ball ammunition in order to standardize all my reloads for my one bolt gun. I have more than 1000 rounds of military surplus NATO 147/150 gr FMJ ammunition in sealed battle packs already.
I thought about ordering pulled or once fired 7.62 Lake City brass in order to standardize my brass so I don't have varying powder measurements to keep up with. I have a good handful of surplus and commercial brass already. I broke out the scale to see which brass matches closest to LC.
I wanted to post the results and get yalls opinion. All brass is de-primed, cleaned, sized, and trimmed. I took a random sampling of the varieties I have a lot of, usually 15+ samples. I am not sure of complete brand name by the headstamps on some but you might. Measurements are in grains:

LC - 176.16
WCC NATO - 176.3
FC (Federal) - 176.21
SSA - 179.79
Hornady Match - 166.72
RP (Remington) - 164.46
BHA - 168.16
MKE (ZQI from Walmart, M80 load) - 169.59
Winchester - 158.02

I am not a long time reloaded but know enough to start low and work up using the right powder and using multiple load sources. Metallurgical differences may exist but I don't see how it would affect the case capacity much.
I'm thinking LC, WCC, FC, and SSA are close enough to work for what I'm doing.

My main question is if there is anything I'm missing regarding case capacity in trying to duplicate this particular load?

Thoughts, opinions, tips are much appreciated.

psa has m80 for 10$ a box. at that price it is tough to justify reloading.

I agree but I also just bought 1000 147gr projectiles at a very good price. Trying to justify and make the best of it.

I use the Quick Load program for reloading and one of the measurements it uses is case capacity in grains of water. You take a case fired in your weapon, weigh it then fill it with water and weigh it again. I haven't tried this with any of my 308 brass but, from what I've read Lake City brass is thicker than commercial brass and has slightly less volume. With less volume the pressures developed will be higher. I'm not sure if this difference will be enough to affect accuracy or cause overpressure issues.

It will affect it from what I've read. I'm trying to have all the ammo hit and perform as close as possible.
Under the assumption that all the cases share the same basic outside dimensions the weight would tell me the inside capacity difference. Most of my load data that I've gathered uses mil spec brass.
The idea being that I would eventually cull out the brass that are different. Ending with having brass that is closest to mil spec.

I would suggest that you invest in a chronograph. As a reloader, it will give you complete control of what you load and you can buy a decent one for around $100. Money very well spent. Chrono your LC ammo, then load to match the same velocity in whatever case you decide to use. I test every load that I produce.

Or if you have a friend with a chrono, have him come out with you at your next range session.

But looking at the weights of the brass you listed, I would pick the MKE. I seriously doubt that you will see any difference with less than 6 grain spread.

I was using Winchester brass for my 308 load for a while until it got too hard to find. I switched to LC once fired and had to drop my powder charge by one grain if I remember correct to achieve the same pressure signs and velocity. My previous load was pretty hot so I definately started lower.