Chassis resonance tips?

[jmikell870]

I've shot a few chassis and stocks over the years. One thing I have noticed, but it never seams to be brought up is the resonance differences between some (Not all) chassis and stocks. However, typically, I notice more resonance with full aluminum chassis systems. Sometimes stocks like Foundations are touted for reducing this effect.
I notice resonance can lead to two subtle effects. Both of which are minor and can be difficult to prove change a system's inherent accuracy or the human interface with the rifle system. Also, I only notice the effects during dry firing. A fired round will mute these effects.
The first effect of resonance is the persistent harmonic ring after the firing pin contacts the bolt face when the rifle is dry fired. This effect is much like the persistent harmonic ring of a tuning fork. The harmonic ring's energy is easily transferred to the high acuity sensing systems in your head. Hearing, vision, equilibrium, touch, ect all add up to compound your subjective perspective. So, I would argue it "feels" like a bigger deal than they really is (getting flicked in the face is worse than getting punched in the arm).
The second effect is reticle hop during dry firing. I notice reticle hoping is worse in chassis/stock systems with more resonances. It's difficult to measure how much reticle hop is mechanical vs human influenced. Also, variables such as the mass of the shooter, shooting position, hand positon, and differing system components make this difficult to measure.
Understanding harmonics resonance is probably a smaller variable. Does anyone try to mitigate the effects of harmonics resonance in their rifle system in a practical way for... Let's say for PRS style shooting? Aside from more known methods like barrel tuners (rubberized or threaded), muzzle brakes, suppressor, adding weights, bedding, or cheek pads. Also, do you notice the same effects of harmonics resonance I describe?

 

[Steel head]

Meh.
If your getting reticle movement on dry firing it ain’t because of chassis resonance.

 

[jmikell870]

Meh.
If your getting reticle movement on dry firing it ain’t because of chassis resonance.

You might be right. But, just because you don't see it, doesn't mean it's not happening. I agree, it might be self induced. Skill is a human factor. I think a lot more people can perceive reticle hop when the effect is magnified, like setting your scope on max power and shooting off a study tripod. I've noticed the effect differences when mounting an isolated camera during dry firing. However, other factors come into play when trying to measure with a camera to prove I'm not the only variable (which I'm sure I am a part of). Shutter speed, rolling shutter effect, focal length and other equipment limitations make measuring difficult. Also, my testing method probably sucks and is not the best way to go about achieving good results. But, it's a fun experiment.
I think you could say, subjectively, the ring can influence your shooting experience. Like the vibration you get from the buffer spring of an AR15. Experiences may very. But, some people change the buffer spring just to enhance the shooting experience.

 

[delfuego]

Finally someone figured out why I am missing 3moa targets at 400y PMS targets.

This will be my new "drive home excuse" for not winning matches.

 

[whatsupdoc]

I really haven't noticed any "harmonic ring" dry firing any of my chassis rifles, the only "harmonic ring" I hear and feel is on some rifles the barrel humming like a tuning fork after the shot.

With that said the worst one I remember was a Ruget M77 varmint bull barrel in 25-06 that would ring like crazy after the shot and that was in a wooden stock that you would think would dampen the vibration.

 

[b2lee]

I shoot a heavy contour 28" barrel with a long action in an MDT ACC. I can put a thumb on the barrel and a finger on the tip of the fore end and squeeze them together to where they touch. When I'm dry firing I see absolutely no reticle shaking....bouncing...jumping. My firing pin is making a very noticeable smack when it hits.

However....I run a TriggerTech Diamond and have always felt that most of that shaking you may be seeing is due to poor trigger pulling and/or a tough gritty trigger. I'll lay in the living room floor prone and focus in on the cabinet door in the kitchen. I'll take my upper left hand quadrant of the scope reticle and align it with the right angle of the door. When I squeeze and the firing pin falls...I see no deviation of my reticle lines moving from the right angle of the edge of the cabinet door.

I run an Atlas Bipod with Hawk Hill claws and a Precision Underground 3D ELR bag in the rear....no shaking. I feel if there was some fundamental that I was failing on this point....it would show up instantly in my ELR shooting....and right now...the only thing kicking my ass in that is poor wind calls.

 

[StrayDog]

I remember the days of harris springs resonating...
Curious about Foundation stocks for their dampening effect, but not enough to buy one.
Gonna stick with aluminum stocks, because like OP said, it doesn't matter when actually shooting!!

 

[Eric32]

I get what your saying, that ping sounds is just annoying if anything else, i suggest bedding your chassis i ran thick skim bed on my old xlr help alot with that sound during dry fire practice.

I didn't notice any accuracy change, brfore and after but it sound alot better.