Written by Sierra Bullets Ballistic Technician Paul Box
Remember how much fun it was when you were a kid to watch those tin cans roll with the impact of those mighty .22 rimfire rounds? Sometimes when we get older we get so serious about our shooting that we lose track of how much fun something this simple can be. I’ll give you an example.
Back several years ago I built a 22-250 Ackley. I chose the Sierra 55 gr. SBT (#1365) for my bullet choice and started some load development. Before long I had a load that gave accuracy down in the .3 tenths of an inch range, but only on occasion. Several groups stayed closer to the half inch mark due to a flyer. Now granted even with the flyer it was still capable of nailing every crow the crosshairs settled on at 300 yds., but what was causing this flyer especially just now and then? I had totally prepped the brass so I didn’t expect the problem was there. Seating depth was another idea, since often times it can cause this sort of problem. So I tried that with no results. After a period of a few weeks this was getting pretty frustrating, so I decided I needed to take a break. The next weekend I took one of my big bore handguns and went to the creek for some informal plinking. Nothing satisfies the soul like seeing mud fly four feet in the air from the impact of those big bore bullets.
With a refreshed mind, I attacked the problem again the next weekend. Sure enough the first group gave this flyer, but this time the light bulb finally went off in my head to mark this case and see if I could find anything wrong with it. Using a concentricity tool I checked the run out on the pressure ring and found it had a banana shaped case body. Since I had only been working with a handful of brass, that was why this flyer was only showing up now and then. Once this case was taken out, groups stayed down in the low .3 tenths range. I learned two things. The effect of a banana shaped case body, but to never lose track of keeping shooting fun.
So the next time you’re feeling burnt out, go roll some tine cans with a rimfire or watch the mud fly with a big bore handgun. It will bring a smile to your face and make you feel like a kid again.