Steyr LP-5 - Erratic Groups

[TonyT]

I have an old Steyr LP-5 which I have used for several years. The last match I encountered a bewildering behavior.
While each 5 shot group was very consistent the distances between individual 5 shot groups was unbelieveable. often exceeding 1 inch.
I am dumbfounded as to the cause of this erratic behavior which I have never experienced prior to last weeks shoot.
Can anyone help me to correct this issue?
Thanks, Tony

[m1963]

Just a thought- is the grip or the rear sight loose? I have seen a similar problem with an Izzy where the rear sight appeared to be secure, but was loose and wandered during a match.

[Rover]

If you're not shooting from a vise with the gun locked on the trigger guard or a tight cylinder, then it's you.

If the two suggestions above don't work, make sure the barrel screws are tight.

[David M]

I know you are referring to a LP 5, but the fault described will happen to a LP 10 with intermittent stabiliser release.
Could it be possible with an intermittent cycling action ?

[SuperIIFT]

This could also be a problem with the regulator sticking
I had this same , with my Evo 10 E
A wee drop of oil on the air fill nipple solved it
Den

[brent375hh]

Also check your compensator cone. I had one build up to the point it was touching the pellet.

[TonyT]

Thanks to all.
Forgot to mention that I was using the Steyr Weaver base plus a Red dot.
Found the problem to be a loose screw on the Weaver mount.

[Rover]

Thanks to all.
Forgot to mention that I was using the Steyr Weaver base plus a Red dot.
Found the problem to be a loose screw on the Weaver mount.

What kind of match were you shooting using a "Red Dot"?

It could not have been an "International".

[TonyT]

A local match for challenged (ie old ) shooters. We shoot off the ISSF rests.