Home Forums Hunting & Shooting Hunting Optics noise on firing

I have a light BR gun. 6mmX47L and I had a problem with groups enlarging noticeably along with what appeared to be two grouping. This is what I call a tendency to place shots into two separate groups. The scope on the rifle was a Sightron S1118-32 x 56. Clicks always seemed to be positive and accurate. I swapped this scope off with a Meopta that has always behaved in the past. 4-16 X44. The limited shooting Ive done with this scope at this point has the groups back in the expected range. Clicks are what they should be , precise and accurate. But, when I fire I get an ungodly(to me)sproing that almost has to be coming from the scope but it is performing as expected.
Any good ideas?

Vibration resonance of some sort.

My M14 used to sproing on the last round when the action remained open, and was more noticeable when I had the scope mounted on it. Then again it had the op rod spring that was probably the culprit.

My Anschutz 22 HB does it (always has a scope on it). My friend has a very accurate TOZ 22 that does it too, once again always has a scope on it - he also has an aluminium stock on it so I guess the vibration travels better into his skull that way.

All barrels vibrate - getting the bullet to leave the barrel at the same part of the vibration is the trick (either through load modification or manipulation of the way the barrel vibrates by adding a weight to it eg barrel tuner). The vibrations die down quickly but the resonance comes from something that is in tune with the frequency and will continue to vibrate at that frequency with minimal dampening ie lasts longer and is more noticeable.

If accuracy is good then it's probably nothing to worry about, unless it ends up killing the scope somehow

When Weaver re introduced the T 16 in the 90s, I put one on my HP silhouette rifle. It made a weird noise I attributed to the adjustable objective bell vibrating. I noticed the later models added a lock ring you could tighten against the bell.

Im either getting used to it now or its fading away. Shooting seems OK.