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Gyro stability 155gr Lapua Scenar vs. 168gr Hornady HPBT match

solst_ice

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Minuteman
Jun 19, 2012
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I've checked the Berger twist rate stability calculator to find the gyro stability of a 155gr Lapua Scenar fired from a .308 20" 1/12" twist at 2600fps at 20F and 300feet. It gave me just marginal stability (the BC would be reduced about 8%) . In comparison, the 168gr Hornady HPBT match at 2550fps would still have comfortable stability. But despite of that, according AB analytics the 155gr would still have the edge over the 168gr at 800m in elevation and windage.

Do I misinterpret something?
What experience do you have running the 155gr Lapua Scenar from a short (20") 1/12" .308 barrel compared to the 168gr at distances between 800 and 1000 yards?
 
That seems really slow for a 155?
That seems more like what speed you'll usually run something like a 175 at from a short barrel.
The 155 ones really do nicely at the intended usual velocities of 2850 to 3000
 
That seems really slow for a 155?
That seems more like what speed you'll usually run something like a 175 at from a short barrel.
The 155 ones really do nicely at the intended usual velocities of 2850 to 3000


I know, they're a bit slow. Using single based powder. The 175gr are running out of my 20" at around 2450fps.