Scar 20S POA Shift when Dry Firing

[Tbd-96]

So I’m running a Scar 20S with a mk5hd 5-25 on a Reptilia AUS mount. I’ve noticed when I’m dry firing, waiting for my barrel to cool, the poa will shift about half and inch. This is weird to me because I’m shooting benchrest off a bipod with a shmedium under the stock and the stock itself jammed into my shoulder.

I’ve also noticed that the rifle will be grouping at one point of impact but shift elsewhere midway through the string of ten. I’m wondering if this is normal for a gas gun or do you guys think that maybe there’s an issue with the scope mount or scope itself.

Thanks.

 

[nn8734]

Your scope mount may be loose but not loose enough to feel by hand but noticable when dry firing (reticle seems to jump) and its showing up on paper.

I saw my reticle jump slightly to the right each time i squeezed the trigger when dry firing my rifle last night (I went shooting this AM). Realized what it was (loose scope base), yanked the scope off and retorqued the scope base screws (added loctite).

 

[BCP]

"I’ve also noticed that the rifle will be grouping at one point of impact but shift elsewhere midway through the string of ten."

No that's not normal, if it isn't a loose scope mount shifting back and forth on the rifle I'd think the barrel might be loose or heat stress somewhere