sparkyv
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Common side...thanks for that.
How do you measure groups
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Nature Boy
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For me it’s easier to locate the outside edge and subtract one bullet diameter than it is to find the center of the hole
lightman
Member
I do the common side thing. Left edge to left edge.
mcb
Member
Statistically speaking anything over 7 is really good and can make fairly reliable predictions of larger groups Std Dev.
Personally I like multiple 5-shot groups only because of shooter focus issues, especially with heavily recoiling guns.
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starnbar
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One aspect to remember did you get 6-8 hours sleep the night before? were you out drinking until 3 am? Yeah groups can change dramatically due to over indulgence in adult beverages the night before same holds true for colds, allergies and the like. The best group is the group you can shoot on your best day.
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AJC1
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barnfrog
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It matters to him.
JFrank
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im not sure I follow the logic’ why are so many shots needed to varify group tendencies ?
By looking at these two separate 500 yard samples below , what additional information is required ?
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Blue68f100
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I shoot 3-5 shot groups to get an indication of what is going to give me the best results. I do not want to waste components on shooting a load that gave a shot gun pattern just to confirm it's that bad. You can if you want, but that's just a waste. Once I find some that look promising, I load another set filling in on the sides. Once I find the best of that run I load 10 or more to confirm, good or bad. If good I load a 20-50 and take them to longer ranges to see if it preforms as it should.
Now if this is for a hunting rifle the odds of you needing more than 2 shots is very rare, or should be. After 2 shots your barrel heats up and they start walking. So 2-3 shots make a good assumption that it will repeat is all that is needed.
Wasting components in this crazy world we live in when components is not readily available is a waste of resources.
Now if this is for a hunting rifle the odds of you needing more than 2 shots is very rare, or should be. After 2 shots your barrel heats up and they start walking. So 2-3 shots make a good assumption that it will repeat is all that is needed.
Wasting components in this crazy world we live in when components is not readily available is a waste of resources.
Archie
Member
I am probably more casual than many.
I have a 'grid' printed on a transparency with concentric one inch increased circles. When I shoot a group, I fit the transparency over the group and shift it around until I get all the shots (disregarding known flyers) in one size circle. That's my group size. Usually in thee or five shot groups. (That is also when I get the chronograph information.) That may be a bit casual for some.
I used to hand out with some bench rest guys. The 'official' measurement at that time (mid 70s) for that sector of the shooting community was to measure the outside edge of the furthest bullet hole with the outside edge of the furthest bullet opposite, then subtract the diameter of the bullet(s) in use. That measurement was using a micrometer.
Probably a little precise for most of us.
I have a 'grid' printed on a transparency with concentric one inch increased circles. When I shoot a group, I fit the transparency over the group and shift it around until I get all the shots (disregarding known flyers) in one size circle. That's my group size. Usually in thee or five shot groups. (That is also when I get the chronograph information.) That may be a bit casual for some.
I used to hand out with some bench rest guys. The 'official' measurement at that time (mid 70s) for that sector of the shooting community was to measure the outside edge of the furthest bullet hole with the outside edge of the furthest bullet opposite, then subtract the diameter of the bullet(s) in use. That measurement was using a micrometer.
Probably a little precise for most of us.
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AJC1
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As you have probably experienced a ten shot string is required in most competitions. Those strings test the total system including the shooter... running the amount of your discipline is a logical path...
Skeptic13
Member
I measure center to center.
JFrank
Member
I guess it depends on the discipline , the main reason we BR guys test and tune with less rounds is to save barrel life and components. We only get a couple thousand rounds of top performance on a barrel or in some cases less so we have to make it count. I try and practice while tuning for a match and let the score keepers measure the group size when I get there. We may throw a couple of full groups down range to ensure we are printing but not too often, I don’t have unlimited barrels but guys that do switch can them for a practice barrel for a informal practice match etc. wish I did have more money for barrels, bullets and powder but oh well.
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AJC1
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I scavenge brass to trade for bullets and powder I completely feel that.
Varminterror
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Only if your bullets produced holes which exactly match their diameter - and not many of us shoot wadcutters out of rifles, or anything at all, really.
Outside to outside, minus HOLE diameter will yield a center-to-center estimate.
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