Measuring A Group

[cleboje]

Guys

I am kinda new to this muzzleloading stuff, so bear with me, but how do you measure a group?

Do I measure from the outside edge of the holes or do I measure from the center of the holes?

Do I measure from hole 1 to hole 2 and from hole 1 to hole 3?

Please tell me the proper way to do this. :shock:

 

[cayuga]

Center of hole to center of hole with the largest spread of shots is the way I do it. There are lots of ways to measure. But basically, it is to give you a ruff estimate of how the load is doing... Good luck.

 

[Lee 9]

A lot of people measure center to center on the fartherest apart holes, some measure from the outside edge of one hole to the inside edge of the fartherest hole[ this gives you the same diamention as center to center but is easy because you have definate edges to measure from. Because I some times dont have many edges to work with I measure from outside to out side then subtract the diameter of the bullet from that. Lee

 

[big6x6]

Because I some times dont have many edges to work with I measure from outside to out side then subtract the diameter of the bullet from that. Lee

...and THAT'S the way to do it! Measure from the outside edge of the two bullet holes that are the greatest distance apart and subtract the diameter of the bullet.

Not the best picture BUT.... I can see from outside edge to outside edge the caliper reads 2.219 inches.. Now subtract the diameter of a 250gr SST, .452 and that gives me 1.767 which I round up to 1.77 inches. That's a SLIGHTLY better number than I reported but 0.03 inch is insignificant in this case.

 

[Underclocked]

Unless you really do not know where the outside edge is. You've probably estimated it well with those calipers but sometimes it is very hard to determine that edge. Unless you are shooting certain target material and/or wadcutters - the edge will not at all be clear. The holes are almost always smaller than a bullet diameter, sometimes considerably smaller.

So, even though that is the accepted way to measure a group, it often results in reports of better than actual group measurements. Subtracting .451 from such a measure when the hole is .35 is cheating a bit. :wink:

I measure ctr-ctr as it seem easier and is probably more accurate most of the time.

 

[SteveB]

I use a yard stick.

Steve

 

[Lee 9]

Underclocked
You are right but I never ran into that problem until I started using BH. Lee

 

[cleboje]

big6x6

Thanks for the pic...it makes all the difference in the world to see how it is done...

Now, being a gear guy, I am going to have to pick up a caliper to get those edge to edge measurements!

I do have to agree, 0.03 is nothing to worry about, especially at 200 yds...Great Group!!!