Y-22,
“I've said before and I'll say again. Banning assault weapons and high capacity magazines will not stop mass shootings but they would lower the body count. Assault rifles and high capacity magazines serve no purpose for self defense or hunting.”
If you are hunting mass shooters, singular shooters, or varmints, a semi-auto 223 is useful. I will grant that it is not a first, or even second choice for large game. An AR-10 would be a much better option. You clearly do not understand the efficacy of a semi-auto action for staying on target. That is the reason that we adopted the M-1 in the 1930s. The Mauser K-98, Carcano M-38, and Arisaka, bolt guns were thoroughly outclassed by U.S. forces during WWII as a result.
Regarding hunting, I agree that 223 is not ideal for large game, but the semi-auto AR-15, chambered in 223, is an excellent choice for criminals, small game, and varmints. It is easier to stay on target with follow-up shots. The AR-10, in 308, is a better general purpose hunting option in my opinion.
“Is the counter argument the second amendment is absolute and we should quit regulating 50 caliber machine guns?”
Yes, stop regulating machine guns beyond a clean background check for the purchaser.
I am not certain what you mean by “absolute”, but Federalist #46 makes it pretty clear that the Second Amendment had an “absolute” function of guarding against government use of force upon its citizenry. Any citizen can own an M-2 with a clean background check, and a class 3 stamp. I personally do not need one because it is not a close quarters firearm (100 yards or less), for which a side arm is more applicable. I can outshoot any 50 BMG cartridge at distance with a 375 Cheytac, or even a 338. You have no idea how lethal a trained citizenry can be.
“Is it I like my gun and I don't care how many people get killed by AR-15's with high capacity magazines I want to keep mine. I don't understand people supporting the weapon of choice for mass shooters.”
No, it is more like; “I want to maximize my ability to kill criminals in a timely manner.”
“I know this only addresses a very small subset of gun violence, but it seems to be the lowest hanging fruit.”
Good reasoning; do it just because you can.
“The bigger step would be to find a way to track guns to find out how gangs and criminals are being armed. Shut down the bad gun dealers and straw purchases and get guns out of the hands of criminals.”
That one seems pretty obvious; shoot criminals.