22 LR Long Range Dispersion, What is the Culprit

[ChrisFetter]

Had a couple of hours on the range this morning. Great weather for Virginia at the moment except for the higher wind today. Rifle is a stock CZ 453 that was put into a Boyds stock this year for a better cheek weld (picture from at different day). I could only get out to 100 yards today since the wind was too unpredictable for my amateur wind calling.

Started 9AM and finished at 11:45AM, 81F rose to 87F through the shoot, roughly 29.2 in. pressure, and 10-15 mph switching winds. Really felt like no exploitable pattern to the wind speed and direction; it was switching front to back from the left side mostly, but the right side gusts would come in to mess things up when groups started looking good. There'd be crazy gusts out near the target with the air dead still beside me, and then crazy wind on my face but a flag near the target was still. A fun challenge to try to call right!

Ignore the X'd hits- my foggy morning brain dialed 27 MOA instead of 27 clicks at the start of shooting, and those were hits while I was shooting at different spots trying to figure out what in the world was going on.

 

[ChrisFetter]

2 weeks ago, there was much calmer weather and I was out at 200- these were the groups I had then with Eley Tenex. The target got a bit crowded since I only had one target with me, but I recorded which shots were part of each group immediately after firing to make sure I didn't get holes mixed up.

 

[ChrisFetter]

Past 200 yards, things start getting a lot more unpredictable with my rifle. A twist rate faster than 1:16" might be better for longer range shooting with .22lr (for the improvement to BC to help with wind sensitivity), but I think the biggest reason people notice .22lr "fall off" past 200-300 yards is that the trajectory curve of the bullet at longer ranges serves as a magnifier for the main rimfire problems: wind sensitivity with a low BC round, muzzle velocity spread, and ammo defects. As the horizontal speed decays and the vertical drop speeds up, all that "small" dispersion suddenly becomes much more noticeable when our bullets start acting more like mortar rounds. Here's the angle of impact of 22lr at 1000 yards for reference (taken from Womfat's video):

A custom barrel compared to a factory barrel can reduce several contributors to dispersion. A tighter chamber, better lands engagement, more consistent bore diameter, etc. all help with raw mechanical precision by reducing the severity of principal axis tilt. A factory barrel CAN shoot just as crazy groups as a custom barrel, but I'm willing to bet what your friend is noticing is that the nice groups happen a lot more often with his custom barrel because it has more inherent mechanical precision. A factory barrel is going to have more slop compared to a custom barrel, because better machining tolerance is expensive.