vertical stringing of shots

[edster99]

Hi all
last night I experienced something very strange - a number of targets where I had the side to side control perfect (5 shots 10m AP) - maybe 10mm wide. However my groups formed vertical lines, 10 to 7. I had one card where the vertical string was not formed and it was a pair in one hole , then I aimed lower and formed a group of 3 bang in the X.
Any ideas? I'm pretty sure its me not the pistol !

Ed

[jrmcdaniel]

At 10M it is not likely to be variation in pellet speed, but that is easy to check with a chronograph. That would certainly cause vertical stringing at longer distances.

Did the lighting change? It seems bizarre, but changes in lighting (perhaps it was sunrise/sunset?) can cause the sight picture to vary and "pull" shots toward the darker side of the target. This can also affect the sight picture as the fuzzy target will "move" depending on lighting and the apparent movement is vertical.

Loose sights? (Happened to me on an M1 Garand and caused a lot of horizontal stringing until I figured that out.)

[Fred Mannis]

Hi all
last night I experienced something very strange - a number of targets where I had the side to side control perfect (5 shots 10m AP) - maybe 10mm wide. However my groups formed vertical lines, 10 to 7. I had one card where the vertical string was not formed and it was a pair in one hole , then I aimed lower and formed a group of 3 bang in the X.
Any ideas? I'm pretty sure its me not the pistol !

Ed

If I get sloppy, let my mind wander, I can get vertical or horizontal stringing because of shot to shot changes in gripping strength and or trigger finger placement. Watch that front sight very closely. Is it moving when the shot releases?

[David Levene]

Vertical stringing can often be caused by not focusing on the sights properly.

It is easier to get the horizontal alignment correct as you have 2 bars of white for comparison. You need to be really looking at the sights to get the top of the front sight correctly aligned with the rear sight.

[macca]

Dear Edster99,
Whilst agreeing with David may I add slightly more.
Most shooting athletes manage to get this pattern when they decide to check their location on the target.

They look towards the target but, oviously, cannot see it as the sights are in the line of sight so they lower the firearm, ever so slightly then realising they are a bit low return upwards as the shot goes off it will have a vertical component in its trajectory.
Are you calling the hi or low or is your call approximately 180 degrees in error?

Just a thought.

[Steve Swartz]

Very common problem with pistol adjusted for "center hold" . . . also creeps in with 6-oclock shooters. Not so common for sub-6 holders.

Commonly an issue with lighting and contrast.

Steve Swartz

[edster99]

My calling of the shots was pretty much off - I wasnt expecting to see a vertical string. What seemed to happen at one point was that it felt as if the sights were getting 'sucked up / in' to the target as the foresight reached the bottom of the target. I am using a 6-oclock sighting picture. This what I got when I shot the two together and high, then when i aimed sub 6 I got the three in the ten. I didnt notice that again conciously but the strings vertically happened in the next few cards after that... so maybe there was something going on related to it. Maybe my shoulder muscles need to get in better trim - I've only started in the last few weeks.

cheers

Ed

[David Levene]

I am using a 6-oclock sighting picture. This what I got when I shot the two together and high, then when i aimed sub 6 I got the three in the ten.

I think you might have answered you own question.

[edster99]

Maybe ! time will tell...