Interest in 100 yard .22LR challenge - 2023 Discussion thread

I get what you're saying about match chambers and ammo lending to consistency.

As for SK, I seem to have had good results with it, not sure what else to say on that subject. I'm not an expert in this field by any stretch.

Are there nicer, more refined, more accurate rifles out there? Absolutely, otherwise people wouldn't pay that premium.

I do think a MKII is better than some give credit for, but I'm not sure why I get so defensive about it lol.

However, my intent was not to start an argument with you, and I did not want to muddy your discussion thread so if you prefer I will refrain from doing so again.

I've enjoyed participating in the challenge and discussion, and I'd like to continue to do so.
 
deadman said:
I get what you're saying about match chambers and ammo lending to consistency.

As for SK, I seem to have had good results with it, not sure what else to say on that subject. I'm not an expert in this field by any stretch.

Are there nicer, more refined, more accurate rifles out there? Absolutely, otherwise people wouldn't pay that premium.

I do think a MKII is better than some give credit for, but I'm not sure why I get so defensive about it lol.

However, my intent was not to start an argument with you, and I did not want to muddy your discussion thread so if you prefer I will refrain from doing so again.

I've enjoyed participating in the challenge and discussion, and I'd like to continue to do so.
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This discussion is exactly one of the reasons for this thread. It's very welcome.

Shooters wishing to learn more about .22LR at 100 should post about their views and questions about the topic. Many shooters often get much of their information and ideas from various forums (and you tube videos) where too often misleading information isn't identified. It's always good to have these kinds of issues discussed.
 
grauhanen said:
Rimfire shooters often assume that a high impact are because a round is excessively "hot" with a significantly higher MV than other rounds. At the same time, shooters assume an excessively low impact is due to an extra MV. They assume that POI and MV have a consistent and reliable relationship. Although the majority of rounds have a reasonably matching POI/MV relationship, quite often this is not the case.

In fact, after tracking the MV/POI of thousands of rounds of .22LR match ammo this shooting season alone, it's obvious that a round's MV doesn't always determine where it hits the target. Some have a POI much higher or lower than their MV would predict. In fact, faster rounds sometimes have a significantly lower POI than slower ones and slower ones sometimes have a significantly higher POI than faster ones. This happens often enough to affect almost every three group target result. Some of these cases are more egregious than others.
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So what are your thoughts as to why this is occurring? It stood out to me since I was testing some 5.56mm handloads on the weekend, and it was pretty wild some of the vertical I was seeing until I hit a certain charge load of powder. I don't have any chronograph data to go along with, so if any fast rounds hit low, and slow rounds hit high I have no way of knowing that. There's no way the velocity spread was enough to account for the observed vertical, especially when pushing around an estimated 3000 fps. What that translates to here, in my mind, is that even if the ammo is reasonably consistent, if the load properties cause the barrel to have an unpredictable and dynamic movement pattern at the time of bullet exit, undesirable results will show up on the target.
 
Leuchtkafer said:
So what are your thoughts as to why this is occurring? It stood out to me since I was testing some 5.56mm handloads on the weekend, and it was pretty wild some of the vertical I was seeing until I hit a certain charge load of powder. I don't have any chronograph data to go along with, so if any fast rounds hit low, and slow rounds hit high I have no way of knowing that. There's no way the velocity spread was enough to account for the observed vertical, especially when pushing around an estimated 3000 fps. What that translates to here, in my mind, is that even if the ammo is reasonably consistent, if the load properties cause the barrel to have an unpredictable and dynamic movement pattern at the time of bullet exit, undesirable results will show up on the target.
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I think it may be much more prosaic, more common and basic. It may well be simply a bullet problem.

Unlike jacketed bullets, soft lead projectiles such as .22LR bullets are very difficult to manufacture with a nearly perfect center of gravity. The result is that POI will be altered in ways that don't always correspond to MV. When tracking MV and POI it is not unusual to see bullets with a certain MVs having a lower or higher POI than others with the same MV. There is a relatively frequent mismatch of MV and POI. Slower bullets can strike higher, faster ones lower and everything in between. It also explains why a very small group can have an ES that predicts more vertical dispersion than exhibited on the group.
 
I haven't read all 144+ posts here but my take on this relates to MV and time in barrel causing variation in the point of exit in the 'barrel-whip wave'. The MV change of +/- 'xx' fps results in exit at high or low points in the whip-motion? I'd guess that milli-seconds variation in time-in-barrel would hit diff points ? In this, I'd also guess barrel-temp would have an effect, with colder barrels having less flex/whip? Over large samples this may be predictable ?
 
Buck1950 said:
I haven't read all 144+ posts here but my take on this relates to MV and time in barrel causing variation in the point of exit in the 'barrel-whip wave'. The MV change of +/- 'xx' fps results in exit at high or low points in the whip-motion? I'd guess that milli-seconds variation in time-in-barrel would hit diff points ? In this, I'd also guess barrel-temp would have an effect, with colder barrels having less flex/whip? Over large samples this may be predictable ?
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The thread is a general discussion thread for all things .22LR and 100 yard shooting. Only a few deal with the question posed recently.

The question of what causes the excessively high POI for MV (and, for that matter, excessively low POI for MV) has nothing to do with "barrel whip". Here's the simple reason why: most rounds have a POI that has a reasonable relationship to their MV. That is to say, most rounds go generally where they should according to their MV. Some rounds, however, do not. Unlike other rounds with a similar MV, they may have POIs that are excessively high or low. A barrel vibrates (or "whips") all the time, for each and every round. It doesn't do it only some of the time or for some rounds.

The center of gravity problem has been discussed in other posts. It explains why some rounds clearly don't go where their MV predicts. It also explains why some ammos group better or worse as distance increases. In other words, center of gravity issues explains why some lots of CX or Midas, for example, do better at 100 yards than others.
 
"In other words, center of gravity issues explains why some lots of CX or Midas, for example, do better at 100 yards than others."

That may be the best explanation yet for those flyers that suddenly go OTS . . . out there somewhere!
While testing different lots at 100 yards the other night, the very last shot was outside the scoring rings low and right.
The ammo was Eley TENEX and the rifle was the Cooper JSR.
I have to find more lots for when my granddaughter brings her skills to the 100 Metre rimfire shoots. Nothing but the best for the little lady!
 
Here's a nice ten-shot group from yesterday, October 17, 2023. Unfortunately the others weren't quite so satisfying. On the bright side, seven of the first ten were under an inch as was the last.

It's at 8.5X actual speed.

 
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