KenK
posted this
10 September 2009
I've shot my Springfield a lot over the past year and thought I had figured out the fouling shot(s) issue. Shooting mostly ten shot groups, the first few shots were generally in the group when I started with a clean and lightly oiled barrel.
I have a couple of bullets that seemed to shoot one about as well as the other (based on my shoddy record keeping) and I decided to try to figure out which would give me the best chance at a good aggregate for four five shot groups.
I loaded 50 rounds of the first bullet at with the same powder charge but two different seating depths. The second bullet I loaded 50 rounds all seated to the same depth but one set of 25 with a light crimp. I started with a clean and oiled barrel for each set of 25 shots.
My test proved fairly conclusively which bullet shot the best aggregate. I have to repeat to find whether crimp or no crimp is best with that bullet.
Now to the point; in all four sets, the first five shot group was the largest by a good bit. No surprise there. The surprise to me, and what I hadn't really noticed shooting ten shot groups, is that in that first “fouling” group there was only one flier in three of the targets, one target had two wild shots. The wild shot seemed to have about an equal chance of coming in shots 1-4.
And, on the fouling target the shots that did go in the group, were much more tightly clustered than in succeding targets. In other words, in 3 out of the 4 targets, four shots grouped under and inch and the wild shot opened the group up to 2- 2 1/2 inches.
The later groups were evenly dispersed and averaged about 1.7 inches.