He was actually demonstrating why dedicated rimfire target shooters use tuners. The slower rounds had found a vibration point that resulted in the bullet exiting as the barrel was pointing slightly more up than the faster rounds. And the fact that the groups were larger points to that not being a true node.
This 22LR journey has been interesting, I don't say much about what I do or my rifles. Last yr at this same time, I had Dixon at LRI spin up a 13tw MW for my initial Rim X, threaded for EC V2. Same boat, a ND trip looming Memorial day weekend. I tested over 15 samples CX and LLR ammo, all I ever had after tests was WTF now.
I measured everything under the sun, all I had was a carbon ring factory. Then one day I ordered some Eley ammo, quite a few samples, night vs day. I bought all I could of the winning lot, 5 bricks. While in ND, I found as good as the ammo was, it started falling apart at 385 meters, or close to 425 yards.
When I got home, looked into diff ammo and found one that was spectacular, with a tuner, my vertical dispersion most days at 5-600 was close to 12" or less as adj were made. Thing was, one in 10 rds failed to make it to the target, up to 6' in front of it. Bad ammo? I bought all 7 bricks left of it. Once I learned not to chase the miss, my hit pct was pretty high. It produced virtually no high fliers, was it worth it, to me, I'd buy every brick that ammo on the planet if I could. Others may walk by it.
I was wondering how good the extended range stuff would shoot. I have some Super LR to test but then I also have CenterX, Midas+ and Xact.
Only one way to find out. Shoot some, lol.
One lot of LLR did well in my Vudoo to 600, 16 tw barrel, 1119 fps ave, when conditions allowed. So I was in the new buzzword "mach trimming" all the time, some over, some under.
But my first Proof carbon shooting CX at 1095fps, probably did the best overall of all my rifles from 50-600 yards. It's a friggin crapshoot!