My K31 has been giving me problems with vertical stringing. It was in unissued condition when I bought it 3-4 years ago. Using the NOE K31 bullet and 15 grains 4756 it would shoot 10-shot one inch groups pretty much on demand. I set it aside for a while concentrating on my 223 and 308 in Production class. Since my nephew and I decided to make our first trip to KC this year, I got out the K31 for the military regional. I had sold my hoard of 4756 to friends so loaded 21 grains 4759 with the NOE bullet. I coudn't get any kind of grouping at 100 yards due to severe vertical stringing. I thought perhaps the barrel is warping from the heat so tried loosening the front band screw (it had to be very tight in the past). That helped so I made a different screw that would let me adjust the tension and hold it there. That worked, or so I thought. I then tried four powders in differing amounts and settled on 21 grains Accurate #9. The target shows my 100 yard sight in target, the right hand 3 shots were first then I adjusted to get the left 3 shots. At 200 yards all my shots were 10s and Xs. I felt pretty good about that and packed up my stuff for KC.
Imagine my chagrin at the match when the vertical dispersion had come back with a vengeance! I tried everything during the match and nothing worked. I did find that AA#9 does burn very hot and intend to use something else in the future. However, I could use some advice on what others may have found regarding proper bedding for their K31s. I would like to finish above last place next year.
