I can't explain what you've seen. I can say that I've seen just the opposite both on target and on an oscilloscope. If you think about it, the bbl is already deflecting more with a mass at the end even before you pull the trigger. An extreme example is some rf br rifles may have a huge 1lb tuner on the end of a .850 straight bbl. You can literally see the bbl bounce when you close the bolt. Not conducive to shooting fast.
Agreed. I was pointing out extreme examples that were both outside of the frequencies we're most interested in but it was to make a point. I still dont want to shoot while the bbl is bouncing like a pogo stick though.
I have made stocks soft enough to bounce like that. Interesting stuff, you would not think they could shoot like that but they do. Just so I am understanding you, your saying that when you hang a tuner on the barrel you will see a larger shift in poi across powder charges and a smaller poi shift on light sport barrels vs heavy contours?
And this discussion regarding frequencies and amplitude is just what I've been focused on lately and finding the comments helpful.
No, that's not what I'm saying. Tuners and powder charges are two separate things. And no, I'm not saying that you'll see less amplitude change on a stiffer bbl than one that's less stiff. Sorry if I said anything that implied that. It's not the case. Putting a mass on the end of the bbl will increase amplitude for a very short period of time, regardless of stiffness but ultimately the amplitude will reduce faster than without that mass. We're only worried about that very short period while the bullet is in the barrel.
Just trying to keep myself straight here but, we have to remember that frequency and amplitude are two separate things. Increasing powder charge doesn't change frequency but does change amplitude. Think of hitting something with a bigger hammer. Powder charge also changes how long the bullet is in the bbl. Remember, we've done nothing to change frequency. Frequency is just a fancy word for time between nodes. For all intents and purposes, frequency is a constant at this point.
Now we get to tuners. They work just the opposite. Forget about amplitude for a minute, it later becomes a "constant". But by means of moving the tuner, you manipulate frequency and frequency is the main factor here when we're talking about timing bbl position with bullet exit.
The biggest part that amplitude plays in tuning is that more amplitude at the bbl translates to bigger groups at the target..when NOT in tune. That sounds like a bad thing but I like it because it tells me more clearly that the gun is or isn't tuned...on target. A short, stiff barrel is harder to see tune with than a less stiff bbl. I think this is what you are getting at with sporters showing more amplitude. That is correct but carries it a bit further than I'm comfortable with. In really good conditions, it's not hard to tune either, but when the wind and reality of shooting competitively come into play, I prefer a barrel that "talks to me" more clearly.
Case in point, I've moved mostly to my own contour that is simlar to a LV and away from stiffer barrels. Stiffer barrels are good in other areas and for different reasons, but as far as reading tune in the real world, I prefer a little less stiffness. That's amplitude.
Now, the benefit of amplitude beyond all that is that the arc is taller but remember, the nodes are frequency dependent. So, we have the same frequency(time between nodes) yet a taller arc, per se. That's how amplitude actually widens the tune window. Now remember, we have the same time between nodes(frequency) but a taller sine wave(amplitude)..So the barrel is spending more time where we want it and less time where we don't, because the speed at the "scatter node", which is technically the node(that's a different discussion). Suffice it to say that we want bullet exit at top or bottom, not in the middle.
Since the frequency is the same but the arc is taller, it spends more "slow time" at top and bottom but less"fast time" traversing the out of tune area. I hope that makes sense to you..or somebody.
I dont think we've been on the same page. Again, powder charge and a mass on the end of the barrel are two different animals. But..if I'm on the same wavelength with you now, it can be explained by the dampening characteristics of having a mass at the end of the barrel vs not. That's a different story but yes, it might be relative to what I think you're trying to describe.
I agree with most of that but I'm not sure how changing powder charge can be correlated to what a tuner does to amplitude. When you change powder charge you're changing several things at once, like trajectory, amplitude and in bore time. I dont see how you can compare the two.
Dude should be buying lottery tickets.
What you are trying to offset exactly is the rate of rise in point of impact vs velocity increase, with a matching rate of decrease in downward muzzle harmonics which is a combination of frequency and amplitude. I am finishing a straight forward procedure to characterize this, and will report soon.
Doing it 100yds minimizes most of the velocity related poi shift. The discussion never ends, but its pretty simple to see on target results.
No, but I cant remember a load with 50 ft of es. Theres something wrong there.
