mcb
Member
Last weekend I did not shoot my best NRL22 match, 7th of 20. So yesterday I went looking for excuses. 
First I figured I had not chrono'ed my gun/ammo in hot weather and that was why I was struggling. I was using 1041 fps (10rd avg SD: 12.0) chrono'ed last September on a cool day. Using the same ammo SK Standard+ (different lot) I got a 10rd average in 86 deg weather of 1034 fps (SD: 13.7). Not nearly enough of a difference to explain my bad performance. I was surprise is was slightly slower, I was expecting a slight increase in velocity.
Next I thought maybe I was using a bad BC. So I checked my 50 yard zero (yellow groups). Then without moving my turrets I move back and shoot groups at 75 (green), 100 (blue), 125 (orange), 150 (black) yards. The "X" marks the point of aim and the circle is the group produced. I averaged the drop for the two 75 yard groups as one was shot in full sun and the other in overcast (I knew lighting made a difference but it was cool to see it on paper). All the rest of the groups were shot in mostly overcast. I think the wind got me on the 125 yard group, it was a windy day and I was trying to shoot in the lulls. I dropped the three low fliers in the 150 yard 10-shot group.
I used Range Buddy to measure the center of each group. When I did the drop measurements none of the group's centers were more than 1/2 inch off what Strelok was telling me they should have been.
I am now forced to accept I was just shooting crappy and my equipment was doing what it should. I did update my velocity and then tweak my BC a few thousands (.132 to .130) and got the error down to less than 3/8 inch.
Going to have to practice more or come up with better excuses...
On a side not I had a box of Sellier and Bellot Club ammo I got off the prize table. I shot one 10 shot group over the Chrono with it, and was impressed. I put 10 shots in a .91 inch (1.74 MOA) group @ 50 yard and the velocity was an average 1110 fps, with and extreme spread of 16.5 fps and a SD of only 4.47. Not quite as good of groups as SK Std+ does in my gun but a fair bit cheaper than STD+ and more consistent velocity. I am going to have to hope the LGS still has some of that in stock and pick up a brick or two to try in competition.
First I figured I had not chrono'ed my gun/ammo in hot weather and that was why I was struggling. I was using 1041 fps (10rd avg SD: 12.0) chrono'ed last September on a cool day. Using the same ammo SK Standard+ (different lot) I got a 10rd average in 86 deg weather of 1034 fps (SD: 13.7). Not nearly enough of a difference to explain my bad performance. I was surprise is was slightly slower, I was expecting a slight increase in velocity.
Next I thought maybe I was using a bad BC. So I checked my 50 yard zero (yellow groups). Then without moving my turrets I move back and shoot groups at 75 (green), 100 (blue), 125 (orange), 150 (black) yards. The "X" marks the point of aim and the circle is the group produced. I averaged the drop for the two 75 yard groups as one was shot in full sun and the other in overcast (I knew lighting made a difference but it was cool to see it on paper). All the rest of the groups were shot in mostly overcast. I think the wind got me on the 125 yard group, it was a windy day and I was trying to shoot in the lulls. I dropped the three low fliers in the 150 yard 10-shot group.
I used Range Buddy to measure the center of each group. When I did the drop measurements none of the group's centers were more than 1/2 inch off what Strelok was telling me they should have been.
I am now forced to accept I was just shooting crappy and my equipment was doing what it should. I did update my velocity and then tweak my BC a few thousands (.132 to .130) and got the error down to less than 3/8 inch.
Going to have to practice more or come up with better excuses...
On a side not I had a box of Sellier and Bellot Club ammo I got off the prize table. I shot one 10 shot group over the Chrono with it, and was impressed. I put 10 shots in a .91 inch (1.74 MOA) group @ 50 yard and the velocity was an average 1110 fps, with and extreme spread of 16.5 fps and a SD of only 4.47. Not quite as good of groups as SK Std+ does in my gun but a fair bit cheaper than STD+ and more consistent velocity. I am going to have to hope the LGS still has some of that in stock and pick up a brick or two to try in competition.
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