What is correlation of twist rate, weight of pellet and speed for accuracy?

[Miles_M]

BC is exactly what I was referring to.

Specifically the BC of the 21.9 AEA versus a 25.4MRD shot from a slow twist polygonal barrel at correct speeds.

I'd be interested in an actual, real world-collected BC, as the % of speed retention the typical way that we use it in airgunning, not the theoretical/rocketeering definition of BC.

(Please refrain from a lesson in theoretical external ballistics here, ballistics programs available to airgunners don't offer all the adjustment parameters to tweak drag laws and form factors, etc , so we fudge it and use the BC as a measure of speed retention, and therefore long range resistance to wind deflection. It's not a perfect method, but it's what we have, and what we use, and quantifies long range wind resistance).

There is no such thing as a "theoretical BC", never has been. Neither is there any theoretical ballistics any more, as all the research labs have been closed down. All we are left with are ballistic laws, fully proven and tested in the real world.

As for tweaking drag laws and form factors, that is exactly what you are doing when you fudge it by changing the BC.

 

[Franklink]

There is no such thing as a "theoretical BC", never has been. Neither is there any theoretical ballistics any more, as all the research labs have been closed down. All we are left with are ballistic laws, fully proven and tested in the real world.

As for tweaking drag laws and form factors, that is exactly what you are doing when you fudge it by changing the BC.

You run yourself in circles Miles. My "please refrain" was directed exactly to you. You recently shared a treatise about how BCs don't change. Now you're saying that it's okay to change BCs.

Much of your "explanations" are theoretical. In theory the BC doesn't change, per you, which I can agree with, theoretically. But in reality we change the BC to get the ballistics apps to match real-world results. As I explained above, it's the only way we can fudge the inputs for what is actually changing, drag laws and form factors, because there aren't modifiable inputs for those.

I appreciate your conceptual textbook explanations, but personally like to deal with tangibles, what we actually see when we're shooting and have to deal with in reality, using the tools available to us, like ballistics apps, true trajectory curves (mapped out the hard way), and chronographs.

 

[Franklink]

As for tweaking drag laws and form factors, that is exactly what you are doing when you fudge it by changing the BC.

Yes, that's what I said.

 

[Miles_M]

Using the Ghost 22 I have taken 1:16 and 1:24 twist barrels and shot many pellets at lots of different speeds. Results show me that the 22gr AEA pellet at 1030fps out of the 1:16 twist barrel works the best over the MRD 25gr pellet out of the 1:24 twist barrel 940fps tail wind, 960fps head wind (best settings for the 25gr).

Yes both pellets have been in both barrels at speeds ranging from 900 to 1050fps.

Why is it the lighter pellet has great accuracy with more spin stabilization?

To the OP. You may find some of the answers you were looking for in this thread. Optimizing Twist Rates for Different Ranges for Pellets. It has never been posted on this forum.