Group size - what is good?

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metermatch
Posts: 196
Joined: Sun Jan 09, 2005 4:30 pm
Location: Los Angeles, CA

ammo testing

Post by metermatch »

I think the original post here refers to a four, 10 shot group average. Why?

Why do people always break their testing down to strings of 3, or 5, or 10 shot groups, just to shoot more of the same groups, and then average the group size, and then think they have a magic number?

When I tested ammo, I typically shot 50 rounds, with me holding the gun prone, with a sandbag under my wrist, through a chronograph.

ALL 50 shots went on the same target. That way you have a much better idea of extreme spread compared to shooting five, 10 shot groups, and average a number, disregarding that those 5 groups may have different centers.

(I have always laughed at magazine article testers who present info on 3 or 5 shot groups to describe how accurate a rifle is!).
Spencer
Posts: 1889
Joined: Fri Feb 24, 2006 9:13 pm
Location: Sydney, Australia
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Re: ammo testing

Post by Spencer »

metermatch wrote:I think the original post here refers to a four, 10 shot group average. Why?

Why do people always break their testing down to strings of 3, or 5, or 10 shot groups, just to shoot more of the same groups, and then average the group size, and then think they have a magic number?

When I tested ammo, I typically shot 50 rounds, with me holding the gun prone, with a sandbag under my wrist, through a chronograph.

ALL 50 shots went on the same target. That way you have a much better idea of extreme spread compared to shooting five, 10 shot groups, and average a number, disregarding that those 5 groups may have different centers.

(I have always laughed at magazine article testers who present info on 3 or 5 shot groups to describe how accurate a rifle is!).
Bravo! Encore!

In ISSF pistol and rifle we shoot 40/60/120-shot competitions: one or two, or more, flyers in competition will cruel your score.
5 or 10 shot groups are only a guide as to whether the ammunition/brand/type/firearms combination is worth further testing.
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