Boresights and accuracy....First time using them, usually I'll just go burn as many shells as it takes to sight in but decided to give the cartridge type bore sights a try. Used one in my 5.56 and the other in my 30-06 and .308. I was really surprised how well they did when I went to actually shooting. I had to spend 4 shells in the 5.56 and 6 in the 30-06. 308 was dead on from the start. Is this normal or just beginner's luck? Also, I sighted them in 1" low at 25 yards in the basement and then shot 100 yards outside. I was impressed. Thought?