Re: Dillon 550B Question
They can do a lot better than that. Like 10-round groups at 200 yards, no bigger than this, easily.
Some years back, I ran a test to see if I could use the Dillon 550 to load QC test ammo, just to speed things up in the range. We were running a particularly heavy production schedule at the time and I was having to load and test fire about 600 rounds (60 groups) a day. We'd use the 550s for pistol ammo for several years, but at that point, I'd never done rifle rounds on them. Using a 223 Rem as the test cartridge, I'd been shooting a run of 52 gr SMKs (HPBT) for about a week, and knew precisely what that run's average accuracy had been. I decided to run some of these on a Dillon 550, and see if I could save some time with them. I changed over a press, and prepped 20-30 rounds. Firing these as ten-rounds groups at 200 yards, they grouped exactly the same as the rounds that I'd been previously loading on a single stage press. No difference whatsoever. I ran the rest of the productin run using test rounds loaded on the Dillon, and compared the average accuracy of over 300 groups, and found virtually no statistically significant change in group size between those loaded on teh Dillon, and those loaded on the Single stage. Keeping all of the groups running right around .7"-.8" at 200 yards, no problem. From that point on, I used the Dillon's for virtually all my 223 test loads in the range. Yeah, they're good!