Very interesting range day.

[johnmventers398]

So, I've just come in from load development for my 16" 243win. I Got some nice groups but the thing I'm am intrigued by is the sound and the feel of the rifle when approaching max loads.

There was prolonged vibrations through the stock. I could feel it like a spring doorstop. And the sound was exactly the same but very quiet . The whole rifle kind of badoinged... Only for one charge worth though. The group was good but more than twicet as big as the best and in fact was the largest of the trip at .87" at. 100yards.

I've never experienced this before. Anyone know what might be going on?

This wasn't the last group of the day and the following group was better at .7"

Best

John.

 

[Ccrider]

Lose screw somewhere.

 

[johnmventers398]

Lose screw somewhere.

I'll check that out. Thanks .

 

[Boisblancboy]

Possible barrel/stock clearance issues?

 

[johnmventers398]

Lose screw somewhere.

Everything is tight.

 

[johnmventers398]

Possible barrel/stock clearance issues?

Nothing has changed. It was literally one group that did it. I'm wondering weather it's a harmonic thing. Screws are tight and everything is as it should be .I think .oh well it still shoots fine so I'm not concerned .

 

[Comrade Terry]

I've got a .308 that does that. It sings to me!

 

[Ccrider]

Did you check your trigger guard screws?

 

[rwj]

Sounds like the action/barrel is responding at a resonant frequency...

 

[Liven The Dream]

Crack in Stock ??

 

[johnmventers398]

Did you check your trigger guard screws?

Trigger guard and action screws are in one . Hugue overmoulded stock with aluminium chassis. Went out this morning at first light super still and init too foggy but still shot superbly well with the previous most accurate load. Just over .25 moa and no ringing .

 

[johnmventers398]

Sounds like the action/barrel is responding at a resonant frequency...

Do you know weather or not that is a good spot to explore or is it an area to avoid giving that it was the largest groups of the day. But perhaps it's a good charge but bad seating depth?

 

[johnmventers398]

I've got a .308 that does that. It sings to me!

How are the group's at .2 above and .2 below? For me .2 below delivers .25 -.3 moa and above was .75. the culprit group was .877

 

[divingin]

Sounds like the action/barrel is responding at a resonant frequency...

I'm thinking you may need to add "stock" into that equation. OP may be hitting the resonant frequency of the chassis at the same point as one of the barrel nodes, causing the entire rifle to act sort of "tuning fork-ish".

 

[dcali]

I’ve seen that happen with a loose screw on a scope mount.

 

[Zero333]

Are you by any chance using a Harris bipod ? I'm just thinking about the springs on the bipod legs.

If you're not using a Harris bipod, then nevermind my post.

 

[dickn52]

Hot load..

 

[284winner]

How about checking to see if that bedding block is somehow detached from the stock at some point. Maybe loose in the stock. Seems like accuracy would be worse but I've seen some darn good accuracy from worse scenarios and couldn't believe it. As said above the short barrel possibly and the harmonics. The combination of it being bolted into an aluminum block could also be the sound/vibration your hearing/feeling.

 

[Texas10]

My 308 does that also, but I only notice it if my headgear is touching the stock. Not shooting off a bi pod, so no other springs to vibrate, but it's an interesting question. Next time out I'll have someone tap the barrel like a tuning fork and listen to see if it's the same frequency.

 

[vonb]

My 308 does that also, but I only notice it if my headgear is touching the stock. Not shooting off a bi pod, so no other springs to vibrate, but it's an interesting question. Next time out I'll have someone tap the barrel like a tuning fork and listen to see if it's the same frequency.

I have noticed the exact same thing and also in my .308. 43.1 gr of RL-15 behind a 175 SMK sings.