Start saving your brass. It’s the most expensive part of the cartridge. Pick up range brass whenever it’s permitted and you get permission to do so. I’ve amassed several thousands of cases for the calibers I shoot regularly that way.
Once I volunteered to sweep up my Police Dept range for free if they let me keep the brass. I ended up with a couple thousand .40 caliber cases that way.
You do not know how many times that brass you picked up was fired. each time the brass is extruded, becomes thinner and elongates, which necessitates trimming the case. Eventually it will rupture in the chamber, but you already know that. I once took it upon myself to weight the cases prior to reloading. There is sometimes 15-30 grains difference between cases of the same make!
If they are sized the same and weigh different, the difference is in the inside diameter, due to thicker or thinner walls, hence different muzzle velocity and different chamber pressures.
It does have an effect on consistency, minimally.
If you reload and are concerned about consistency, and therefore long range eye of the needle accuracy, use the same lot, use your own known history brass, and check each and every load for charge as well as case weight.
or, just cheat and buy a case of Federal premium 168 hpbt, or for flatter trajectory, try their 165g spbt, which has Vere good performance stats.
Prints 2 inches high at 300n yards.
Thanks for the advice! Once I figure out what I’ll be shooting, I’ll do so.