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Posted: 3/27/2011 12:26:08 AM EDT
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I loaded a some Montana Gold 55gr, and pulled ss109 in .224 with pulled WC-486? It said to use H-335 charts. I went to the range on Sunday, I was packed. I had to wait for a table. I got a wobbly one  .I shot my groups. 24.3, 24.5, 24.7, 24.9 in both weights. And they were crap. So I went home reloaded the same bullets, powder, and even the same brass ( mean the same brass as the last trip) but went up in 10th, from 24.3 to 24.7. Well with a good cement bench and sandbags I got 10 shot group that measured .865" from the 24.4 charge. Shot in under a minute. @ 50yrds. So do I take the .865 and subtract .223 to my my group size? If so I got .642" which is not bad considering the bullseye was mostly gone  and I am using cheap bulk bullets and pulled powder.
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Quoted: I loaded a some Montana Gold 55gr, and pulled ss109 in .224 with pulled WC-486? It said to use H-335 charts. I went to the range on Sunday, I was packed. I had to wait for a table. I got a wobbly one .I shot my groups. 24.3, 24.5, 24.7, 24.9 in both weights. And they were crap. So I went home reloaded the same bullets, powder, and even the same brass ( mean the same brass as the last trip) but went up in 10th, from 24.3 to 24.7. Well with a good cement bench and sandbags I got 10 shot group that measured .865" from the 24.4 charge. Shot in under a minute. @ 50yrds. So do I take the .865 and subtract .223 to my my group size? If so I got .642" which is not bad considering the bullseye was mostly gone and I am using cheap bulk bullets and pulled powder.Remember, 1 Minute of Angle (MOA) is approximately 1 inch at 100 yards, 2 inches at 200 yards, 3 inches at 300 yards, etc. Good shooting!
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Quoted:
You subtract .223 if you measure from edge to edge, but I thinkc the holes int he paper are actually smaller then .223, so the most accurrate way is to just measure from center to center and dont subtract anything How do you know where the exact center is, other than eyeballing it? Wouldn't it be easier to measure outside diameter of a hole, then subtract that from outside edges of the group? |
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Quoted: Quoted: I loaded a some Montana Gold 55gr, and pulled ss109 in .224 with pulled WC-486? It said to use H-335 charts. I went to the range on Sunday, I was packed. I had to wait for a table. I got a wobbly one .I shot my groups. 24.3, 24.5, 24.7, 24.9 in both weights. And they were crap. So I went home reloaded the same bullets, powder, and even the same brass ( mean the same brass as the last trip) but went up in 10th, from 24.3 to 24.7. Well with a good cement bench and sandbags I got 10 shot group that measured .865" from the 24.4 charge. Shot in under a minute. @ 50yrds. So do I take the .865 and subtract .223 to my my group size? If so I got .642" which is not bad considering the bullseye was mostly gone and I am using cheap bulk bullets and pulled powder.Remember, 1 Minute of Angle (MOA) is approximately 1 inch at 100 yards, 2 inches at 200 yards, 3 inches at 300 yards, etc. Good shooting! I was using both Montana Gold bulk 55gr and ss109 pulls, with pulled surplus powder. |
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Quoted:
Quoted:
You subtract .223 if you measure from edge to edge, but I thinkc the holes int he paper are actually smaller then .223, so the most accurrate way is to just measure from center to center and dont subtract anything How do you know where the exact center is, other than eyeballing it? Wouldn't it be easier to measure outside diameter of a hole, then subtract that from outside edges of the group? I've seen this used a lot on the LaRue forum: http://ontargetshooting.com/ There is a freeware version that works really well if you have a scanner. Can use a camera also. I've onlyl done one target so far, and used a scanner. It seems real nice. |
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Good performance if you ask me.
So you know, there are a lot of different ways to measure group size. The most common method of extreme spread really isn't the best, and I've started to move away from that method. That method is overly dominated by the occasional flier and doesn't really represent the practical accuracy. The method I use now was detailed in the GCA journal, and is also used in the On-Target software another referenced. It takes only a few more moments than extreme spread, and I find it a lot more meaningful. For group sizes, firing three 10-shot strings is the technique I use now. The steps are simple. 1) Draw a horizontal line such half the impacts are above, half below. 2) Draw a vertical line such that half the impacts are to the left, half to the right. 3) Where that line intersects is roughly the mean point of impact. Obviously there can be some variability, but it'll be close enough for practical purpose (this is one piece of data extreme spread won't tell you already) 4) Measure the distance from that point to the center of each impact hole. 5) Average those distances, and that's your mean radius. Mean radius is a smaller number than extreme spread, but it tells you, on average, how far a shot is going deviate from your point of aim. This method dampens out the effect of 1 flyer, but doesn't completely neglect either. Because everyone who measures extreme spread almost always discards that one flyer - which, unless you called it, you shouldn't really do. |
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