My first ever "Batch" I crushed 23/100 pieces of brass because I couldn't understand how to seat and crimp at the same time. Since I had that experience I was emotionally violent towards this operation so I seat then crimp. I took my 77 cartridges to the range only to find that the Lee precision minimum loads ripped nice tears down the side of the brass, but I was like: "Hey, it works!". After this I talked to the gunsmith and he told me to reduce the load by about 20% and it didn't tear my brass a new one so I was happy, until I found out that those hot loads caused my magazine catch to break so my gun had to go in for repair. That's with a 9mm pistol, let's talk about rifle ammo.
First shot of reloaded .303 ever I started with the Lee minimum starting load and guess what, case head separation. I ended up driving 40km to get to the range and fired one shot while sitting by the clubhouse staring at my 49 shots thinking to myself: "Should I?"
Or the other day I was going too fast on my turret press and the primers weren't being seated 100%. The firing pin was actually setting the primers and the second strike was firing them, on every single round. Guess how many rounds I made? 1500 haha. Do I put on body armour and a paintball mask and try to set those primers further while the cartridge is loaded? I'd be up for a darwin award and dressed for the occasion.
Welcome to reloading dude, stop at 6 beers if you want your ammo to work the next day.
And never tell your friends that you're doing weird stuff like putting dental floss on your brass and filling it with pistol powder. Never talk about putting brass in the oven or using plastic hammers to pull bullets, they're never going to understand trust me. Never try to tell them that your reloads are more accurate than the $50.00 / box hunting ammo they buy.