How long does a barrel vibrate after firing, Calfee?

K

Kathy

Guest
My friends:

Been testing 2 new rifles today........

This is going to sound silly, but, do any of you engineer type folks know how long a barrel vibrates after it has been fired?

Does it vibrate for a second? Two seconds? ten seconds?

Does a barrel vibrate longer if it has a muzzle device attached? (some folks call those things a tuner)

Is this subject important? It may, or may not be, but after what I experienced today, at the range, during the tests of these two rifles, man, I've got a dumb idea floating in my head..........

My engineering friends, how long does a rifle barrel vibrate when it's fired?

What if you get in a hurry.....on a card....moving as fast as you can, bull to bull........are the barrel vibrations stopped, when you move to the next bull?

For my dear centerfire friends, when you catch a condition, and put them down range as fast as you can, has the barrel vibrations settled, between shots?

I saw something at the range this AM, that I've never seen before....I've probably see it before, but didn't know what I was looking at...

MY engineering friends....could you lend help...."how long does a rifle barrel vibrate after it's been fired?"

Thanks in advance for your imput...

Your friend, Bill Calfee
 
My friends

My friends:

Sorry, I wanted to say something else.........it ain't just the vibrations when the barrel is fired........if you fire a round, then move to the next bull, close the breech bolt, the barrel vibrates.......if you push the rifle forward and it hits the foreend stop, the barrel vibrates.......if you dial to the next bull, then stop, suddenly, the barrel will continue to vibrate....

My dear engineering friends.....how long does a barrel vibrate after it's been fired, or bumped or????...

I saw something today that I've never seen before......my friends, if I can figure out why.........

Again, thanks in advance my enginering friends, I know you folks can solve this problem.......

YOur friend, Bill Calfee
 
What I would like to do is make a clamp that would clamp onto the bbl and hold a tuning fork parallel to the bore. I would like to see how the tuning fork is excited by the various actions involved in firing at a target. It would also be interesting to see what happens to the poi when you give the tuning fork a good whack just before firing.
 
Bill, Maybe if you told your engineering friends what it was that you saw, they might be able to help..Kinda like asking your doctor for a diagnosis with out telling him of the complaint.
Personally, i think there are too many variables at work here, diameter of barrel, velocity of ammo and temperature would all come into play and have varying effects.
Hope you find your answer.
Don.H.
 
Bill,
I've noticed this in my crosshairs of my scope for I don't know how long. I've been touching my barrel from time to time around mid section to limit the time of these occilations to be quicker to the next bull and be accurate. Can't say it has worked, can't say it hasn't but I noticed it., especially after closing the bolt. It may be better to actually touch the tuner rather than mid barrel to stop the vibrations but I haven't tried that yet and shooting in matches or tournaments with no practice is just not always the best place to experiment. I've thought of a dowel rod with some fabric at the end to use to touch the tuner, but touching the barrel mid section seems to work just as well.

Carp
 
Ringing the barrel

Why not just ring the barrel and see ?

Dont you ring the barrel to see where the dead spot is ....

So pick the spot that rings the longest/loudest and see how long it vibrates ....
Im sure some one has a sensor for such things .... Or at least a super sensative microphone ...



Matt
 
Over 1 Minute and Cumulative,

I am not one of the lucky people who never change their tuner.
One day my 40X will be hammering with a certain tune (Happy Rifle) and the next day in the same conditions I will struggle to hit an X (Un-Happy Rifle). When this happens I reach up and try a few clicks on the tuner. My next shot after turning the tuner will usually be a donut. I have learned that this is not an indicator of what my next 2 or 3 or 4 shots will do but does confirm my POA vs POI.
This has give rise to my “ManHandle the Tuner Technique” (MTT)
On a calm day and I have an UnHappy Rifle(UHR) I can reach up between ever shot, MTT, and improve my X Count. Interesting thing is that if I have to wait too long between shoots this technique is not reliable. Another is that even thou my X count might go up my score will not improve.
Ops I am Rambling and dancing around Bill’s question. The truth of the matter is I do not have an answer except some uneducated guesses.
My Barrel will continue to vibrate for well over a minute after a shot.
If I have an UnHappy Rifle these vibrations will be cumulative with multiple shots with timings under one minute between them. (Cumulative meaning a different frequency than if I had waited over a minute between shots.) The un predictably nature of this cumulative effect leads to maybe 5 X’s and a dropped shot -2 or -3.
I am off to the range today to test some homemade add on weights for my tuner.
During this testing I will try to get a gut feeling how long these viberations last.
 
I have noticed vibration in some barrels more than others. The lighter profiles and reverse taper come to mind. A mid barrel dampener is very effective at killing this but the worst vibration is the bench vibration you get with steel post benches. One range that will remain nameless in Texas has benches that you have to lean against between shots to kill the vibration and then avoid touching before firing
 
Doug
How do you know or can tell your rifle vibrations over a minute ? All of mine seem to stop by the time I sight in on the next bull.
Fred K
 
Just an observation here, but, my wife's Winchester 52C came with a small piece of rubber under the rear of the action and under the barrel at the end of the barrel channel. Could Winchester have put those pieces of rubber there to dampen or eliminate barrel vibrations. That rifle shot great with those rubbers in it..

What do you think.. ??? Would a piece of inner tube or another form of rubber under the barrel stop vibrations.. Just curious..

Dave
 
Inner tube

Dave:
You've just discovered my tuning secret. I've used a piece of inner tube under the barrel of my 52C, since 1970. Never had a vibration problem. My 52D, for some reason or another, did not vibrate after each shot. I have seen other barrels that did visible vibrate, but the shoot was smart enough to allow for it.
 
i thought i read somewhere that someone

maybe melvin forbes was using an occilliscope or something
to tune barrels with, maybe a frequency analyzer, anyway
wouldn't something like that show when all vibrations had stopped.
bill if you're thinking that it's still vibrating well apparently there
are some who never knew and never let it bother them to shoot
some great scores anyway. so?
 
This is another one of those questions asked without a good definition of what is really being asked, and really raises other questions. For example what is meant by "no vibration" - is it 1/100 of what was there at the start or is it 1/10000? If the vibration decays by 1/2 each cycle then how many cycles will it take to drop to zero? (Bill, ponder on this for a while because this is kinda the way it works.)

Then if the vibration drops to 1/10 what it was at the start will this be enough to affect bullet flight? If it gets down to 1/1000, is this for all practical purposes, zero and will have no effect on the bullet?

If you want a for-all-practical-purposes, down to earth engineering answer, then the answer is the vibration stops immediately. If you want a correct scientific type answer then the barrel never stops vibrating until acted on by another force. If you want an answer determined by measurement then you must specify just how sensitive you want the instruments to be, and below this sensitivity constitutes "no vibration"
 
My friends

My friends:

I added a post to the centerfire forum where I had asked the same question...

I don't know how to move it over here without completely re-typing it....

YOur friend, Bill Calfee
 
Built two rifles.....exactly the same.....one barrel slugged so it wound up a half inch longer than the other....otherwise, identical....the same fellow bedded them...same stocks......etc...

Shooting off a hard rest system I sighted the first rifle in, had the muzzle device set at a place that has worked on several guns like these.....the thing was extremely flat, no vertical, going to be a killer, went to an ARA card....started shooting, I've always been kinda of a runner, and was punching the dot out then I'd get a 1:00 scratch 50 or one at 7:00.....more at 7:00...

I got to fooling around and started waiting between shots....started with 10 seconds.....worked much better, then 9 seconds and finally to seven then six.......it seemed if I would wait at least 8 seconds between shots this rifle would just cut the dots out......

So I would then shoot four rounds, waiting 8 seconds, usually center punched, then I'd quickly move to the fifth bull, find my spot and pull the trigger.....more than half the time I'd get a 50, either 1:00 or 7:00....more at 7:00.....

I moved the scope to the other rifle, ran the same test and got the exact same results, I mean identical......

At this time I really ain't sure what's causing this.....is the barrel still vibrating, or is it my rest system......I ain't sure yet....

See, I'm a pistol shooter and have always been a runner....with some success...but I'd always get an odd shot or two, or three on a card but I always figured it was because I'd sometimes not hit my spot .......but now I ain't sure............

Your friend, Bill Calfee



Copy and paste.
 
How long does a barrel vibrate?

How long does a barrel vibrate after firing? That is the question.

Forever! It will get less and less over time, but if you let it, it will just lay there and quiver. With each added shot it will quiver differently.

There now, I hope I have helped you.:)

Concho Bill
 
To Bill Wynne..

You're right on. I pointed out the same thing in my earlier post. Funny how anything said that comes close to the truth is just ignored by these guys. I can't figure what goes on in the mind of Calfee, the Calfee followers, and even the nay sayers.. It appears they want to just talk, while saying nothing. They don't seem to want to, or can't read what is said in the posts - or maybe they just don't understand what is posted. Anyway, it's kinda fun to just watch!
 
Pacecil,

I don't think you were ignored. Your post didn't draw immediate overwhelming response, but didn't seem to draw negative fire. You said the barrel vibrated forever until acted upon by some other force. What type of force and would that stop the vibration or merely change it. The earth vibrates all the time and would obviously transfer the vibration through a concrete bench to the rifle, thus that would be "some other force". Where Bill shoots, there are railroad tracks about 75-100 yards away, so they would vibrate all the time from the train until acted upon by "some other force". At least the bench will vibrate when the train comes by. I would say it's an ambiguous question whether intentional or not. The barrel would have vibrations at all times, but not necessarily from being fired. I think the correct answer is the one you gave for all practical purposes. It stops immediately.
 
Hmmm

Well , I don't see it vibrating for ever [ If your looking for a response ]

Simply due to the fact that its attached to a stock , which sits on a B rest that sits on a table which is attached to Mother Earth , and all of which will absorb the vibration to some extent .

And lets not forget some barrels are bedded , or have preasure points or those Rubber vibration dampeners [ Tuners ] ...

Sorry , dont see it ...

Calfee sais 8 seconds ... [ I say he is wrong ]

But , he may be right that the detrimental effect lasts for 8 seconds in rifles he builds , I will not argue that point ... Esp since it takes me longer than 8 seconds to reload in anyway ...

I hope this response helps ...

Matt
 
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