Re: 1,010 Meters (1,104 Yds) .308 20"
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: bohem</div><div class="ubbcode-body">Good shooting!
There's a piece of clarity shown on that target here. Something that is a pervasive internet myth strengthened on this site and many others:
"The 30c 168gr bullets do not fly well past 800yd because of going transonic"
This is not always true:
The 168 SMK has a lot of trouble until you get to higher altitudes (above 5000' DA's at least from the testing that I've done)
The 168 Hornady BTHP is similar to the Sierra but seems to do OK above about 1800-2000' DA's, the boat tail design is better.
The 168 Amax is the same as the 168 BTHP and works fine over 1800-2000' DA
Just because it is a 168gr 30c bullet doesn't mean that it will not work, it just means that you need to monitor the DA you shoot it at. It is also not a blanket statement about the 168gr but rather on what design it is:
<span style="font-weight: bold">For instance, I know that the Berger 180gr Hybrid in 7mm doesn't transition well under 3000' DA, which is the highest that I've shot it. The bullet transitions a lot farther downrange (my 280 Rem and 7/300 WSM have both hit targets at a mile with the bullet) but that doesn't change the fact that it doesn't transition.</span>
The 140 Berger VLD in 6.5mm has transition issues from everything I tried it in.
The 140 Amax doesn't have trouble even at -300' DA
The 142 SMK 6.5mm doesn't have trouble at -300 DA either.
Track your DA, track the bullet type, and keep good data, you'll get a better idea of what bullet you can shoot to where.
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Bohem,
What twist are you using for the Berger 7mm 180's? I use a 1-8" and that helps a lot.
To the OP, that is pretty impressive!
I don't think this thread 'busts' the 'myth' that the .308 falls out of the sky once <span style="color: #000099">{edit: it reaches transonic/subsonic}</span>. I think it gives a clearer understanding of which bullet types remain more stable under a given set of circumstances. I think this thread is incredibly helpful to those new reloaders who want to push their limits and what to use while attempting it.
One myth I hope this thread puts in it's place is that 20" barrels can't shoot to 1k(+). If you have enough velocity and stability, the bullet will get there.
