Best ES with most shots, what's good enough

[PWNolan]

Here is my personal new best that I've shot with a 1 in 12 twist shilen

How did it do down range? I could care less about ES or any of those other numbers. All that matters is how it does on the target

 

[grauhanen]

ES and SD don't always prescribe or guarantee the trajectory of the rounds involved.

Put another way, when compared to each other the MV of match ammo rounds from the same lot don't always match their POI.

 

[CharlieNC]

The physics of ballistics dictate a faster bullet will impact higher. But we do not know where the fast vs slow exits on the harmonic curve, ie degree of positive compensation to minimize target poi differences. Lower SD issues better, but no universal cutoff value is possible.

 

[grauhanen]

Wind and shooter influence aside, the physics of ballistics with .22LR dictates trajectory -- such as a faster bullet having a higher impact -- only when the bullet itself is perfectly formed. When it's not, the trajectory is less predictable. One result is that MV and POI may not match.

Soft lead projectiles such as .22LR bullets and airgun pellets are very difficult to manufacture to nearly perfect form. Some bullets will be less perfect than others. Here form includes such characteristics such as center of gravity as well as bullet shape and dimensions, especially the all important bullet heel. When these are less than perfect, trajectories can't be perfectly predicted.

 

[Hi-NV Shooter]

The physics of ballistics dictate a faster bullet will impact higher. But we do not know where the fast vs slow exits on the harmonic curve, ie degree of positive compensation to minimize target poi differences. Lower SD issues better, but no universal cutoff value is possible.

Logically with all barrels when at a static state would have some droop (pointing down) so looking at PC a faster bullet will exit earlier than slower one therefore wouldn't POI be higher for a slower bullet since the barrel will have time to obtain maximum upward movement.
and because earlier exit with the faster bullet would be lower in the barrel's upward movement. POI will be lower. with PC trying to find that window where both intersect and exit timing is the same for both fast and slow bullets will give same POI. I never seen it yet, I don't think it is possible.

Lee

 

[CharlieNC]

Logically with all barrels when at a static state would have some droop (pointing down) so looking at PC a faster bullet will exit earlier than slower one therefore wouldn't POI be higher for a slower bullet since the barrel will have time to obtain maximum upward movement.
and because earlier exit with the faster bullet would be lower in the barrel's upward movement. POI will be lower. with PC trying to find that window where both intersect and exit timing is the same for both fast and slow bullets will give same POI. I never seen it yet, I don't think it is possible.

Lee

The vibration frequency is fast enough (10-20khz) but the lack of knowledge required to engineer the amplitude tor exact compensation is lacking. So for center-fire a charge weight ladder can yield a "flattish" poi node, much less sensitive but not perfect. Or the weight of a tuner to help. All better than being on the down swing of the cycle which would magnify the effect of velocity differences on the target.

 

[grauhanen]

Same barrel, same MV, different POI. It's not barrel harmonics.

Wind and shooter influence aside, when two or more rounds of the same lot of match ammo are shot through the same barrel and have the same MV but have different POI in the vertical plane, that difference wouldn't seem to be related to barrel harmonics.

Something else must be different. What's left? The bullet.

 

[Hi-NV Shooter]

The vibration frequency is fast enough (10-20khz) but the lack of knowledge required to engineer the amplitude tor exact compensation is lacking. So for center-fire a charge weight ladder can yield a "flattish" poi node, much less sensitive but not perfect. Or the weight of a tuner to help. All better than being on the down swing of the cycle which would magnify the effect of velocity differences on the target.

CF is a whole different animal since you can alter the load and refine it to come close to what you need before fine adjusting with a tuner. this is often injected into rimfire discussions. IMO it is useless in the discussion pertaining to RF. until someone uses factory loaded CF ammo and tunes a rifle to be competitive on the same level as RF rifles are in BR there is no comparison.
In RF since we cannot adjust loads, and some will say using different lots is the same which anyone who shoots RF knows it is not the same as reloading CF. at best you can match AOL to the barrel/chamber in RF. and even this is limited as RF ammo also has variances in bullet diameter. again, reloading CF this can be vetted out of the equation.
so, with RF it is about exit timing using the tuner. adjusting the tuner to compensate for the ammo's velocity differences to get as near perfect exit timing for both slow and fast the basis of PC

Lee

 

[CharlieNC]

CF is a whole different animal since you can alter the load and refine it to come close to what you need before fine adjusting with a tuner. this is often injected into rimfire discussions. IMO it is useless in the discussion pertaining to RF. until someone uses factory loaded CF ammo and tunes a rifle to be competitive on the same level as RF rifles are in BR there is no comparison.
In RF since we cannot adjust loads, and some will say using different lots is the same which anyone who shoots RF knows it is not the same as reloading CF. at best you can match AOL to the barrel/chamber in RF. and even this is limited as RF ammo also has variances in bullet diameter. again, reloading CF this can be vetted out of the equation.
so, with RF it is about exit timing using the tuner. adjusting the tuner to compensate for the ammo's velocity differences to get as near perfect exit timing for both slow and fast the basis of PC

Lee

We all know CF is different, the point is it is useful as a tool to understand harmonics. A barrel doesn't know if RF vs CF was the source of ignition. Or you can choose to ignore the CF understanding for RF applications.

 

[ROBARRC50]

Been a while for me shooting 22. I was finally able to get back out. Here is sk std plus 60 shot string out of a factory cz 457 mtr. Includes cold bore completely cleaned barrel. This ammo flat out shoots in my rifle.

 

[S&sprecisionTx]

Had to go out and check my zero on my 1_14 shilen

 

[Todd Earhart]

Had to go out and check my zero on my 1_14 shilen

This was a good lot. We had 2 cases of this lot.
Todd

 

[TRSR8]

We all know CF is different, the point is it is useful as a tool to understand harmonics. A barrel doesn't know if RF vs CF was the source of ignition. Or you can choose to ignore the CF understanding for RF applications.

Not for nothing but you’re preaching to a guy about RF ballistics that could give you lessons.