Re: 180g sst subs
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ColdBoreMiracle</div><div class="ubbcode-body">In my limited experience, the drag may not be as bad, but the accuracy at distance suffers with RN bullets. When I shot the Hornady 220RN as my primary SS load, I found that the best I could do was around 1.5-2 MOA out to about 300yds. Beyond that was a total crap shoot.
Shooting the high BC Berger's I've increased my max range to nearly 500 yds with sub moa patterns when I do my part. </div></div>
Wow, that's impressive distance! What's your dope for that?
I can't attest to accuracy differences, as my testing with subs has been limited to just a few bullets, but I've found it easier to achieve smaller velocity spreads where pressures are higher. Concerning BC, here is an example of what I have found in my research:
You'll see that BC decreases with velocity in the 175 SMK and much more drastically in the 210 SMK. However, you'll also see BC <span style="font-style: italic">increase</span> as velocity decreases with the 220 Round Nose. Since the relationship of BC and velocity isn't linear, and I don't know the math behind it, I can't speculate as to what happens at subsonic velocities. It wouldn't surprise me if the RN surpassed both SMKs, though. A teardrop shape is the most efficient shape at subsonic velocities, hence the experiments of seating boat-tail bullets backward. And I'm with you, Deano, I have no desire to play with that sort of thing where fast-burning propellants and high pressures are so near my face
Anyway, my point is that conventional wisdom changes significantly below the speed of sound. Also found in my research is a lack of a lot of data, so I'd love to see any findings any of you come up with. Thanks.