Lemonaid,
That's great, and there's plenty of data here to work with.
Here are your results graphed and you can see the relationship of velocity and group size. As I said, choosing optimum charge weight based on velocity (only) is a clumsy proxy for what you really want - which is the smallest group size. Bullets can come out the barrel with good standard deviations of velocity but still be pointing in different directions due to barrel whip, or simply because the bullets are poorly made and not concentric in shape or weight. Suggesting you can find the optimum charge weight by shooting only 10 rounds and looking at velocity is almost negligent. Given shooting is a game of statistical averages imagine a Satterlee outcome which is more towards the edges of the Normal curve than the middle. There's more chance of this happening with only 10 rds. You then spend the rest of that barrel's life shooting a load you are convinced is the best it will ever produce, and you will be wrong.
[ATTACH=CONFIG]15628[/ATTACH]
Unfortunately I am not seeing a useful trend here other than your groups were getting better as the load got hotter. If you started the test by shooting lightest loads first then maybe you got better at shooting on the day or maybe the gun was clean and it took a while to foul and settle. The up-down group size between .2 grain loads by such large group sizes on the target suggest something is, with respect, not right. You cannot say with confidence that a particular load is best for your barrel.
If the barrel follows the usual harmonics there should be a sinusoidal wave of group sizes to indicate the load area that you should hone in on. The velocity line should be as straight as possible to indicate consistent loading, neck tension and the measuring device is fine. If you are loading in the dark, especially compressed loads then a steep curve up in velocity is a danger sign.
I have not used A2200 but QL is telling us that the max load is 28gns, which from that program is always conservative (but it is safe). At your OAL it is 95% full so not a compressed load. That sharp curve upwards approaching 29gns may just be a Magneto precision error and not a danger sign, and I say this because the rest of the velocity line is not exactly straight.
You note two group sizes where one group has an outlier. In your shoes I would not discount any shots unless at the time you are convinced the fault was yours, and not the gun or ammo (e.g. you flinched or slipped).
My thoughts are that you need to re-do this test. Now that you know the load range is safe I would start 5% low and work up instead of 10%. If you want to keep 29gns as the max (absolute value) then shaving 1% off to 1 decimal place is;
29
28.7
28.4
28.1
27.8
I have highlighted two cells in yellow in your data; the '2818' is a standout and you can see by the standard deviation (107) that something is not right here. Having a round 200fps out from the rest is obviously a mistake in the machine, the recording, or loading. The other reading; 2681 in your post is different from your hand written velocities on the target (2691). Only one of them is the correct velocity.
Here is my OCW for 4rd groups of 130AR Hybrids using 8208 out of an 18" barrel. I am looking for a tightest groups closest to the max safe load, which looks to be around the 26.7 mark. So, looking at the red line I am interested in the low points or troughs of the curve. Plus a sinusoidal MOA curve which suggests the barrel has predictable harmonics. Point to note: the max load is a stout load which is a little compressed so it's a good thing the tightest group is a full grain back from the max.
[ATTACH=CONFIG]15629[/ATTACH]
Here's another OCW for the new Nosler RDF (Reduced Drag Factor) line of bullets. Their BC is currently the highest in the 6.5mm 130gn range, and looks like they have achieved this by making it longer and pointier than all others. So they expect users to have plenty of magazine length to accommodate the longer tip; which unfortunately is not the case in an AR.
Out of a heavy 26" barrel 6.4*47 bolt gun everything is more precise than an AR; the groups are tighter and more consistent. Although there is a predictable sinusoidal wave of precision and it goes a further 50-metres, the average group size of the Nosler RDF is not as good as the Berger 130AR Hybrids. Whether this is because my barrel 'likes' Bergers better or that the Berger is a more consistently-made/better quality bullet is debatable but the RDF's are going back on the shelf.
[ATTACH=CONFIG]15630[/ATTACH]
This is a pity because the graph is suggesting the most accurate load is also the max safe load...the best of both worlds. But, as I say, the RDF's are not as precise as the 130AR Hybrids, at least in my gun.
That's great, and there's plenty of data here to work with.
Here are your results graphed and you can see the relationship of velocity and group size. As I said, choosing optimum charge weight based on velocity (only) is a clumsy proxy for what you really want - which is the smallest group size. Bullets can come out the barrel with good standard deviations of velocity but still be pointing in different directions due to barrel whip, or simply because the bullets are poorly made and not concentric in shape or weight. Suggesting you can find the optimum charge weight by shooting only 10 rounds and looking at velocity is almost negligent. Given shooting is a game of statistical averages imagine a Satterlee outcome which is more towards the edges of the Normal curve than the middle. There's more chance of this happening with only 10 rds. You then spend the rest of that barrel's life shooting a load you are convinced is the best it will ever produce, and you will be wrong.
[ATTACH=CONFIG]15628[/ATTACH]
Unfortunately I am not seeing a useful trend here other than your groups were getting better as the load got hotter. If you started the test by shooting lightest loads first then maybe you got better at shooting on the day or maybe the gun was clean and it took a while to foul and settle. The up-down group size between .2 grain loads by such large group sizes on the target suggest something is, with respect, not right. You cannot say with confidence that a particular load is best for your barrel.
If the barrel follows the usual harmonics there should be a sinusoidal wave of group sizes to indicate the load area that you should hone in on. The velocity line should be as straight as possible to indicate consistent loading, neck tension and the measuring device is fine. If you are loading in the dark, especially compressed loads then a steep curve up in velocity is a danger sign.
I have not used A2200 but QL is telling us that the max load is 28gns, which from that program is always conservative (but it is safe). At your OAL it is 95% full so not a compressed load. That sharp curve upwards approaching 29gns may just be a Magneto precision error and not a danger sign, and I say this because the rest of the velocity line is not exactly straight.
You note two group sizes where one group has an outlier. In your shoes I would not discount any shots unless at the time you are convinced the fault was yours, and not the gun or ammo (e.g. you flinched or slipped).
My thoughts are that you need to re-do this test. Now that you know the load range is safe I would start 5% low and work up instead of 10%. If you want to keep 29gns as the max (absolute value) then shaving 1% off to 1 decimal place is;
29
28.7
28.4
28.1
27.8
I have highlighted two cells in yellow in your data; the '2818' is a standout and you can see by the standard deviation (107) that something is not right here. Having a round 200fps out from the rest is obviously a mistake in the machine, the recording, or loading. The other reading; 2681 in your post is different from your hand written velocities on the target (2691). Only one of them is the correct velocity.
Here is my OCW for 4rd groups of 130AR Hybrids using 8208 out of an 18" barrel. I am looking for a tightest groups closest to the max safe load, which looks to be around the 26.7 mark. So, looking at the red line I am interested in the low points or troughs of the curve. Plus a sinusoidal MOA curve which suggests the barrel has predictable harmonics. Point to note: the max load is a stout load which is a little compressed so it's a good thing the tightest group is a full grain back from the max.
[ATTACH=CONFIG]15629[/ATTACH]
Here's another OCW for the new Nosler RDF (Reduced Drag Factor) line of bullets. Their BC is currently the highest in the 6.5mm 130gn range, and looks like they have achieved this by making it longer and pointier than all others. So they expect users to have plenty of magazine length to accommodate the longer tip; which unfortunately is not the case in an AR.
Out of a heavy 26" barrel 6.4*47 bolt gun everything is more precise than an AR; the groups are tighter and more consistent. Although there is a predictable sinusoidal wave of precision and it goes a further 50-metres, the average group size of the Nosler RDF is not as good as the Berger 130AR Hybrids. Whether this is because my barrel 'likes' Bergers better or that the Berger is a more consistently-made/better quality bullet is debatable but the RDF's are going back on the shelf.
[ATTACH=CONFIG]15630[/ATTACH]
This is a pity because the graph is suggesting the most accurate load is also the max safe load...the best of both worlds. But, as I say, the RDF's are not as precise as the 130AR Hybrids, at least in my gun.