Shifting group

[TAJ45]

Been shooting BE since the mid 70's. I did have a 25 year layoff but have been back at it for several years now and have shot as high as 863-23 out back, measured and timed. However, 830 seems to be more of the norm of late - esp with these probs. Clark on my 41 w/a 4 Dot UD, factory grips. Prefer a medium firm grip. I do NOT switch dot sizes, period. Not even for someone else to "try". I do find my "natural" position before beginning.

In the last 4 months, randomly it would seem, my group will shift to the 1-2 o'clock quadrant in SF. Just abt 2-3 rings. I won't make any corrections - it's just an informal league at the local indoor range. I'll shoot either a 20 yd tgt or 25yd tgt at appropriate distance then most of the time the following sustained tgts will be very nicely grouped and centered. Maybe the slightest favoring of a click high.

Often enough also, my first ten SF that are "out" will be followed by the second ten pretty well centered, again with the discrepancy being N. of the 3-9 line.

Tonight, out of 6 tgts (a 600), only one was randomely grouped on ctr. ALL of the others were between the 7-8 rings.

I've threatened but now plan to stick another Match Dot on that I have in the wings for the .45 but never mounted. All units are previously used. Current one has been on the gun for 5? years or so. Ammo is or has been CCI std vel, cardboard with the occasional SK or MT for the long line at a match.

What say you?

[Rover]

Change the Match Dot; then you'll know. It could also be the mounts.

[davekp]

I had a similar problem- the center of the group seemed to change laterally when going from slow to sustained fire. The problem was my failing to pull the trigger straight back in sustained fire. Cured by lots of dry fire concentrating on straight back.

[GunRunner]

what dot size do you use, if its the 4moa, dump the match for a standard one.
Also take a screwdriver and turn your elevation and windage screws one full turn then back to its setting, ive had uds get off and this fix them

[Isabel1130]

I dont think it is the sight.

I believe you are making a consistent error, that is, at times shifting your POI.

I would guess, it is most likely an anticipation error, but something is happening in your grip, your wrist or your triggering to throw your shots high right.

[oldcaster]

I had a match dot mounted on a 22 that did the same thing except it was right and then back to the middle. About an 8 inch discrepancy. Something was loose inside the scope. When I sent the scope in for repair, I received it back in about 5 weeks with a target enclosed that was shot with a 22 and would be an embarrassment if it were shot at 100 yards with the note saying the scope worked fine. I found out that means fixed. Good luck!