This is true. It's a factor that many do not tend to believe until actually shooting. The theoretical belief seems to be held as the standard. It's believable that a 245 grain 308 bullet and a 300 grain 338 bullet with identical BC's with a MV of 3000 fps will have identical ballistics(only an example assuming BC is close in both bullets). This is true in a tunnel with zero wind. Once wind is present, the picture becomes completely different and completely in favor of the heavier projectile. The shooters that have done the work, will agree 100%. Those that have not seem to follow the theory of ballistics and it is just not so. ELR competitions show this with the 338 caliber and up being the winner of these events predominantly. While It's still a blast shooting the smaller caliber cartridges at these extreme ranges with excellent success and low recoil no doubt, the big bore heavies get the job done more successfully. I still prefer the 90 grain .224 over the 95 grain .244 bullet to 800 yards. I think it's close in terms of over all accuracy in wind conditions but the edge (for me ) has been with the 90 VLD (.224). I can't shoot the 95 due to lack of stability. It would definitely be the winner in this comparison.
I have not seen what you have at all, and I have had to estimate wind holds on things that most normal folks will never have to as part of my job. You are entitled to your own disbelief, but beginners reading here should not go down that path as a result because the vast experience of the industry and the models are well established.
I too was skeptical as a young start in the business, but as a young student scientist I had much to learn from the ballisticians at my company, the national labs, and armories. We all get to learn in different ways but you must remember that it is one thing to have your own suspicions about external ballistics and another to lead more folks down the wrong path about solidly established ballistics.
If you have low or little faith in your ballistic solver in terms of the ability to predict windage of a common small arm, there is probably not more I can do or say to convince you, but while I wait on my girls I will try to prevent some youngsters from accepting the wrong theory.
There is lots of nuance to internal ballistics when it comes to pushing state of the art, on that we can all agree. We can hardly predict things when it comes to group size or what matters when it comes to BR level shooting. We let the competition at well attended events establish our expectation of performance level should be. But when it comes to the bit about external ballistics being discussed here, we are in a pretty secure place with ballistic solvers that you can play with for free on the internet. I have already run the examples in post #13 above.
I am not calling you out, and please don't take this post the wrong way. As what I hope becomes a favor to you and the rest, allow me to bring the benefit of a long career where I was responsible for putting ordinance on targets. For practical purposes, you can give yourself a better intuition by playing with the results of the ballistics solvers if you don't want to drag yourself through a whole study of ballistics.
You need not take the word of a retired aerospace/defence guy. I have no idea what you saw on that day, or what your experience is when it comes to playing with something like a Kestrel and a ballistic solver over a very wide variety of projectile weights, but imagine the uproar of complaints if those were all as wrong as you are suggesting?
Here is an example set you can run for yourself that helps illustrate why your observations were an anomaly of the day and not the way things work.
If we standardize on a 15 mph full value wind and distance of 1000 yards to make this simple. Take your favorite ballistics solver and estimate the windage of two bullets of equal BC and as much difference in mass as you can find. Since we are discussing bullet weight, I will try to find real ones with as much difference as possible but with the same BC to help illustrate the point.
Make the speeds the same and check the trajectory. Finding the examples isn't easy for the very reason that mass is part of BC, but I find the Berger 7mm 184 F-Open comes up in the 284 Win enough to be popular, and the heavy end of the Berger 6.5 153.5 would be good for illustration since the difference in mass is roughly 20% yet they closely match for BC. This should convince anyone who has used a modern ballistic solver and a Kestrel on an honest range to estimate wind.
Berger 7mm 184 F-Open G7 0.356 @2800 fps ..................................... wind drift is 87.16"
Berger 6.5mm 153.3 Long Range Hybrid G7 0.356 @2800 fps ....... wind drift is 87.16"
In fact, even their drop would be identical even though there is a 20% difference in their mass. So, at the same given speed, with a matched BC, your earlier observations would have been due to a bad day and not the difference in weight because the BC accounts for it. YMMV
