I always wanted to try my hand at long range shooting but haven't had the chance.
The best I've done is blow up water filled milk jugs consistently at 300 yds with my 30-30 and ring 18"x24" steel until it got boring at 400 yds with an AR using a red dot and TulAmmo.
I'm not an ELR shooter, it was something to try for the first time. I generally shoot inside 1000 yards. My ballistic app works inside that envelope. It crapped the bed at a mile because I haven't tuned my velocity and set my BC to different velocities. It would be nice to have a personal drag model for my load (I doubt I'll ever have that opportunity) or a custom drag model from Applied Ballistics. Their ballistic app has custom drag models for specific calibers/bullet weights based on their testing.
My best is 1117 yds on an 18” gong in New Mexico. Huckleberry75 rifle and his dope. I was just the trigger puller. Dead calm, first shot 6” right, next three swung the gong. I was pretty impressed with his setup.