Rifleman Mythbusters - Shot Group Analysis Challenge

[308LIBERTY]

I've been discussing Shot Group Analysis with a number of instructors lately, in an effort to refine the way we instructors approach problem solving. After much deliberation, I thought it would be fun to turn this into a learning moment for us all. It's one thing to read shot groups off that good ole yellow sheet, but there's no comparison to actually doing something yourself and seeing the results, so I'll start with an easy topic...or is it? 

CHALLENGE NUMBER ONE: CANTING
Ammo Requirement - 25 or 50 rounds (depending on how much you want to expend on this)

Step 1: Using our popular "squares" target and starting off with your rifle properly sighted in, go ahead and shoot a good group of 5 or 10 rounds on the center square, to show us you started off well sighted in.

Step 2: Now "cant" or tilt the rifle 45 degrees clockwise and put either 5 or 10 rounds on each of the top 2 squares.

Step 3: Cant the rifle 45 degrees counter-clockwise and put either 5 or 10 rounds on each of the bottom 2 squares.

Step 4: Take a photo of the full sheet and post it here.

(Always wear eye and ear protection and follow the proper safety rules)

[Caliper]

Also, let us know what is the height of the sights over the bore.  Another often-discussed element of this issue.

[308LIBERTY]

Good point, especially if you zero, with iron sights, using 6 'o clock hold. This should have more of an effect.

Also, let us know what is the height of the sights over the bore.  Another often-discussed element of this issue.

[azmule]

Are you sure?  Cant is unlikely to be an issue at a 25M first zero.  For full effect, do this as above, then repeat at 300yds and compare results.  Maybe have a spotter for 300yds to tell you how far off paper you are.

[Guntuckian]

Cant has very little effect unless there is a significant "come up".  Without having to aim significantly  _above_ the point of impact, there is no significant effect other than a slight tipping or diagonal effect.  But, when shooting at distance, i.e., at more than about 250 yards, cant begins to have a very large effect, that only increases at distance.

- Gary

[308LIBERTY]

Ya'll are missing the point. The header of this thread is called "Rifleman Mythbusters" It's a TPI learning exercise. I want to see ya'll put holes in paper and show it one way or another. If you've got the distance to shoot it past 25m, post pics of your targets.

[Lomshek]

Running an Appleseed this weekend and will do it Sunday if time allows.



Kind of curious how much of a smiley face I can draw if I fire 5 rounds slowly changing from one cant extreme to the other with each shot.

[Mark Davis]

Okay I suck at following directions.
I used the same zero that has been pretty good shooting offhand at recent schutzen matches. about 2 minutes low off the sand bags I used today.
I canted the rifle counterclockwise on the top squares, and clockwise on the lower two.
My center of bore to center of scope may be screwy because the scope is mounted with 55 minutes in the mount system.
Todays zero fired from 25 yards, is three minutes the lowest sight setting of the scope. The scope has 96 minutes of elevation possible.
So my line of sight is not really in the center of the scope.

[Mark Davis]

100 yard groups. With the scope set on my preferred 6X the cross hair more then covered the squares.
I fired 10 at the center and five at each of the 2 far left squares with the rifle canted clockwise, judging 45 degrees was much easier at 25 yards because I could line the crosshairs on the corner of the squares. At 100 yards it was more guesstimate.
Only fired the two groups canted because more shots would either miss the paper or blur the results.
It was rather Valley Forge like at the range today with drifts up to 4 ft tall.