New to measuring groups...

[Bluto65]

specifically 22lr groups. From what I have read you measure, calipers in my case, from farthest edge to
farthest edge of the group. The diameter of the bullet is then subtracted, 0.223 in the case of 22LR.
So if shot a group of 0.3186 in and subtract 0.223 the result is 0.0956. This is smaller than the bullet diameter. I did this at practice yesterday with RWS 50R, Anschutz 2013 and a Nightforce BR.
This is my first time shooting 22s, I usually shoot 6mmBRX and 6mmBR. The 22 is for practice, eye trigger coordination and WIND. It is hard to believe that I shot 5 times thru that dinky hole!!!!

Did I measure and calculate correctly??? Doesnt seem to follow laws of physics, its like putting a square peg in a round hole.

 

[Codeman]

The math is correct but how are you measuring to the ten thousandth.

The thinking is a little off. You didnt put the shots in .0956 hole- you put them in a .3186 hole and .0956 from all being in the exact same hole. .0956 is the variance from being in the same hole.

Still fine shooting.

 

[Bluto65]

I used a digital caliper to measure the groups. AHA! So the records are kept and recorded based on the variance of the shots, very interesting, makes sense. I thought I was going nuts when guys were writing about groups measuring 0.145 etc. Thanks for clearing this up for me. Remember that 0.0956 was one of about 40 some groups I shot that day, guess it was luck and a relaxed mind. Guess dinky groups are what the call bug holes. I have now seen one with my eyes!!

22LR is really fun to shoot!

Cant beat my 6mmBRX F-Class matches at 600yds though, they are fun and tough when there is wind!

 

[aj300mag]

If you're using a digital caliper measure the diameter of a single bullet hole and zero the readout. From then on measure the outside of the widest point of your group and you'll have a direct reading of your group size. Bullet holes in paper are seldom caliber size.

 

[normmatzen]

Craig,

Where in heck did you find ammunition for that much shooting?

I have considered shooting my cheapie "match" 22 for practice, but can't find good ammo.

 

[normmatzen]

Bluto65,

Just checked your data and found you aren't the "Bluto" I shoot with here in CA!

 

[Lee Martin]

I use a dial caliper too. Example:



0.405" outer edge to outer edge minus 0.224" = 0.181".

-Lee
www.singleactions.com