cool.
Out to 300 yd... hmm.
String of thoughts here.
1. First things, which you've probably already covered, but to be sure. Barrel (check), optics, trigger.
2. For out to 300 yds, whatever bullet shoots best (what your barrel likes) would be fine. No particular order. 103 eldx, 105 hdy/bthp, your scenar, 107 smk, tipped version 107 tmk, (I don't particularly like - 108 eldm), bergers Vldh or others... And, since you're going for <0.5 moa... stability/adjustability of your rest.
The pics above suggest that the rifle is a good shooter and your load is probably pretty good, but;
3. Now I'm just an average guy, no expert here, but when I see a more or less consistent "flyer" cropping up I think it's something shooter, or position, or eye-blink, momentary loss of focus, body/finger twitch, those things.
The rifle is a mechanical system, so other things being equal, it should behave like a mechanical system, with some statistical pattern of the group. Now for my theory: To check group size for an OAL tweak I need 4, maybe 5 shots -- that way I can see either a normal pattern (mechanical system behaving, no other issues), or (don't know what to call it) an "affected" pattern. Statistically, a mechanical system should produce a rounded pattern of some diameter "x" due to its random variations, smaller the better but you get the point. An "affected" pattern will show some kind of pattern-outlier: the two most-often I see are 3 in a small triangle and 1 flyer far enough out to qualify as a flyer, or a "2 and 2" group. These tell me I did something, can't blame the bullet or load.
Is your MV on or near a mechanical node? If not then load tweaking is the first thing to do. As I look at MV, OALs, and exit timing, a powder delta of 0.1 gr is a larger effect than an oal delta of 0.010". So settle on the gross measure first (powder), then adjust the length, then proof test over a few sessions.
Row "#3" - does this indicate a better and better attempt at zero left to right? (ie, shooter)
Row "#4" First 2 groups show me a "flyer" but as an "affected" pattern (there really needs to be a better term for this!). By the 3rd group you're settled in.
Anyway, these seem to be more of shooter-oriented issues, which btw is often the case with me!
Edit to add: much of the fine tuning is a process of trouble shooting, correct the biggest error-effects first, then the ever smaller ones. By trying to correct a more minor effect leaving the bigger one untouched, you won't see any solid progress, any small correction will be masked by the larger effect still looming over your target results.
Out to 300 yd... hmm.
String of thoughts here.
1. First things, which you've probably already covered, but to be sure. Barrel (check), optics, trigger.
2. For out to 300 yds, whatever bullet shoots best (what your barrel likes) would be fine. No particular order. 103 eldx, 105 hdy/bthp, your scenar, 107 smk, tipped version 107 tmk, (I don't particularly like - 108 eldm), bergers Vldh or others... And, since you're going for <0.5 moa... stability/adjustability of your rest.
The pics above suggest that the rifle is a good shooter and your load is probably pretty good, but;
3. Now I'm just an average guy, no expert here, but when I see a more or less consistent "flyer" cropping up I think it's something shooter, or position, or eye-blink, momentary loss of focus, body/finger twitch, those things.
The rifle is a mechanical system, so other things being equal, it should behave like a mechanical system, with some statistical pattern of the group. Now for my theory: To check group size for an OAL tweak I need 4, maybe 5 shots -- that way I can see either a normal pattern (mechanical system behaving, no other issues), or (don't know what to call it) an "affected" pattern. Statistically, a mechanical system should produce a rounded pattern of some diameter "x" due to its random variations, smaller the better but you get the point. An "affected" pattern will show some kind of pattern-outlier: the two most-often I see are 3 in a small triangle and 1 flyer far enough out to qualify as a flyer, or a "2 and 2" group. These tell me I did something, can't blame the bullet or load.
Is your MV on or near a mechanical node? If not then load tweaking is the first thing to do. As I look at MV, OALs, and exit timing, a powder delta of 0.1 gr is a larger effect than an oal delta of 0.010". So settle on the gross measure first (powder), then adjust the length, then proof test over a few sessions.
Row "#3" - does this indicate a better and better attempt at zero left to right? (ie, shooter)
Row "#4" First 2 groups show me a "flyer" but as an "affected" pattern (there really needs to be a better term for this!). By the 3rd group you're settled in.
Anyway, these seem to be more of shooter-oriented issues, which btw is often the case with me!
Edit to add: much of the fine tuning is a process of trouble shooting, correct the biggest error-effects first, then the ever smaller ones. By trying to correct a more minor effect leaving the bigger one untouched, you won't see any solid progress, any small correction will be masked by the larger effect still looming over your target results.