Thin barrels that heat up quickly will typically shoot two touching, then fliers, each subsequent shot further than the one before as the barrel gets warmer/hotter. I have an old sporterized Model 96 that I turned down similar to a Win FW and it does that with every load I've tried over the years, and in three different stocks.
I have a 6.5x55 with a Krieger #1 barrel that exhibits this pattern when I fire three rounds back to back to back. Need to take it out on a calm cool day and let the barrel cool between rounds to see if it mitigates the issue. If that settles out, will try 5 shot groups...
... If you super imposed each target over the others do the two shots close to each other without the "flier" always land in the same point of impact repeatedly. In other words if you stacked ten of your 3 shot group targets together would 20 shots land in the same spot with 10 random flyers outside the main group?
I have considered trying a variation of this a couple times. Permanently fix a target to a target backer. Tape another target over top of it. Shoot a 3 shot group. Remove and replace the top target, Shoot another 3 shot group. Rinse and repeat 5 times. Measure the "15 shot group" on the original target. Rinse and repeat 5 more times. Measure the "30 shot group". Draw comparisons to the average of the 3 shot groups...
If anyone has done this ^^^^^^ and can post a link, would be appreciative...
