"Fun" at the range.....

[gitano]

Brithunter keeps track of how a rifle shoots by using a "permanent target" that one always puts behind the new target for the day, thereby keeping a record on the "permanent target" of the rifle's precision. It's a good idea. He has a post on the subject some time back.
 
I do the same thing, except I don't use a "permanent target". I simpy digitize an image of the target shot for the day, and use their x/y positions to fill in a composite target thereby keeping a "permanent" target record of the rifle's (and my) shooting. Since kombi provided four 3-shot groups that he shot, I thought I'd use those to illustrate how I keep my records, and provide some idea about kombi's rifle's precision at the same time.
 
Below you will see the composite "target" of kombi's four 3-shot groups. In addition, there is a 95% Prediction Ellipse. That ellipse is the statistical estimate of the area into which 95 shots out of 100 would fall from that rifle with kombi shooting it with those loads.
 
The horizontal width of the ellipse is 2.85", the vertical width is 1.39", and the area of the ellipse is 3.12 square inches. The horizontal dimension being 2-times the vertical suggests that kombi has a trigger "pull" issue. Of course there could be a bedding issue that causes the horizontal stringing, but given the four independent groups, that's less likely than "operator error".
 
Now before I get jumped on for "criticizing" kombi's shooting, this outcome is not uncommon, and the 95% Prediction Ellipse area is actually quite good. This type of anlysis is precisely how I detect 1) shooting problems I have, and 2) bedding problems I have. Lots of shots is the only way to detect small "bad trigger habits" AND subtle bedding problems. BIG stringing and "pulling" the trigger are easy to detect. It's the subtle ones that this sort of analysis teases out.
 
Oh yeah... I notice that the pictures kmbi posted were rotated 90 degrees from the "proper" orientation of the printing on the pictures. If they were shot with the printing oriented rigt-side-up, then the ellipse would also need to be rotated 90 degrees. In that case the stringing would be vertical instead of horizontal, and would indicate tha the 'problem' wasn't "pulling the trigger", but rather, bedding.
 
Paul

[kombi1976]

Thanks for that, Paul.
I take all constructive criticism on board for, as those who've read my hunt report know, I'm far from being an experienced shooter.
There is another factor though.
I adjusted my scope 3 times during those groups which changes things a lot.
Next meet I'll try and make a more scientific approach so it's possible to see how it's really shooting.

[Alboy]

Thank
There is another factor though.
I adjusted my scope 3 times during those groups which changes things a lot.

 
Which tells me you and the rifle are doing pretty good even during dialing in efforts. For round numbers 1 1/2 x 3 inches is a good hunting load. Once you have chosen your final scope setting and load that will most likely shrink dramatically.
 
Mainly I feel Paul is trying to share a valid long term accuracy procedure check for both shooter and weapon.

[gitano]

There is another factor though.
I adjusted my scope 3 times during those groups which changes things a lot.

Not necessarily. I knew you changed your setting in the middle of group four ("1/4 click" - relatively insignificant), but unless you moved the settings significantly in the middle of shooting one of the other groups, the groups sizes would be the same. If indeed you did move the scope settings within one or more of the groups, then the above is indeed invalid.
 
In fact, even if you did adjust your 'scope in the middle of a 3-shot group, as long as you noted the amount of adjustment, the shots could be equally adjusted to compensate for it, and the group's size still obtained. Subtracting the average value for each 3-shot group from each shot within that group "centers" the group on "0" and allows all of the groups to be superimposed. That's how and why multiple groups can be 'put together' even though they are shot at different targets or even on different days. You lose the information between Point of Aim and Point of Impact, but you gain the ability to create large sample sizes for estimating the real precision (group size) of the rifle/shooter combo.
 
But, as Al said, this was more an exercise for illustration of a procedure I use, rather than a careful analysis.
 
Still waiting for the 'goat hunting report'.
 
Paul

[Nelsdou]

I cringe a bit on seeing 3 shot groups after what I did today.

Wanted to confirm the 6.5x55 load I'm taking next month on a hunt and shot a 3 bullet group at 100 yds.  Got 1MOA.  Moved the target back to 200 yds.  Got another 1MOA.  Pretty happy with that but I couldn't leave well enough alone.

Tweaked the scope to bring down the print on the 200 yd target down a smidge.  Shot a 3 bullet group and it came down but opened up to 2~3 MOA.  Fussed with the scope and shot another 10 rounds to realize the dispersion wasn't getting any better and it was time to head back to the barn to investigate what was going on.

Found that everything was snug and tight but my scope ring screws.  They weren't completely loose but they weren't snug as they should be either.

Now if I'd stopped after shooting the second 3 shot group and called it "good" I wouldn't be.  I plan to "shake down" this rifle again to check the scope and that means no fewer than 20 rounds for me to feel confident in it.

But then again, I just like to shoot.

Nels

[gitano]

But then again, I just like to shoot.

Amen to that!
 
Paul[/SIZE]