Home Forums Hunting & Shooting Ask The Gunwriters 53 grain V Max

Doubt that's right, as it would only be a little over 1/4 inch long!

.830" according to JBM's table.

.830 including the tip, subtract.141 to get the jacket length which is generally used in stability calculations
I get about.75 including the tip and 1.25 or thereabouts for the metal bit

I used .830 with a tip of .141 according to JBM in my calculations. But sometimes those lengths are not correct. At 29.9 pressure, 59 F and 3050 velocity, an 11 twist gave 1.558 stability

Adjusted BC is reduced to .266
Litz lists the 50 V max at .228 and 55 at .249 but I haven’t checked his parameters

Hornady lists it at .290. That is what I use when using their ballistic calculator. It is pretty dang close. Good enough to hit a miniature sized yote silhouette that was quartering away at 800 yards, on a cold bore challenge. The best thing to do is load some up, shoot them at the range and adjust as needed..

When you do the math on a good program, the 53 V-Max twisted 1:14 doesn't stabilize. The plastic tips can be a bit misleading on this, though. But there's no doubt they are on the ragged edge.

The proof of the pudding is always on the target, though. Many button rifled barrels will measure faster than their stated twist. And the hammer forged Remington barrels generally run about .5 faster.

With a good program like JBM's Drag/Twist calculator, it's easy to see that velocity is a minor driver in stability. Bullet length (not weight) and twist are the main drivers of the Sg number.

It's my experience that well before you see stability issues 'on target', the rifle will get temperamental to tune and show inconsistencies in come ups and windage. In other words, the bullet doesn't have to show keyholes on the target to be unstable. Keyholes on the target are simply the most extreme manifestation of an unstable bullet.

Good shootin' -Al

Dvor has em on sale, $18. a box.

My 14 twist 220 Swift didn't shoot them well at all.

I got 1.409 stability at 3800 fps (.220 Swift velocities) with a 12 twist using JBM's length of .830 and tip of .141 at 59 F and sea level. So not sure if JBM's length is correct.