09/06/2026
Model-24 comparator & concentricity test instrument.
You have done all your homework,
Rifle built and barrelled by the best riflesmith,
Best optics. repeatable and true in movement.
Projectiles, primers, and brass, meticulously selected, prepped, and batched.
Powder, weighed to the kernel after extensive testing.
Now you have sub, half MOA groups with an extreme spread in MV in single digits.
With a ballistic solver to increase your ability to hit close to the X ring and find the centre of your group with minimal rounds to increase accuracy, giving you that edge to win.
What you have missed.
Every projectile is slightly different, even in premium projectiles; every manufacturing process has its bell curve, which is why there can be as much as 3%-5% variation in extreme spread in ballistic coefficient.
Projectiles,
* Measuring for length will ensure each round has an identical stability factor.
* Pointing projectiles can increase BC and ensure base-to-tip conformity if done correctly, but you are playing with the aerodynamic profile, which much smarter engineers with unlimited resources and testing have at their fingertips, having balanced shape calibre in a dance to find the best stability in all conditions. Any lateral wind will have varying results and cause stability issues as the projectile comes down through the Mach numbers; that pressure wave moves forward as it gets closer to the transonic region, with some surprising results. Insert (where did that wayward shot come from?), all things being equal, it is also an aerofoil, and you just played with its leading edge.
* Many even weigh each projectile. Why, as once again there is a variation, and the perfectionists will remove this variance as much as humanly possible.
Each point above contributes very little to the variation in ballistic shape of each projectile in relation to any other in a batch, with respect to drag and induced drag to differing amounts of non-concentricity of each projectile on its longitudinal axis.
Your tuned load with muzzle velocity in the single-digit ES realm, printing sub, X ring groups at 100 yards, may have as much as 50fps ES at 1000 yards with a vertical spread of 8”, nearly the height of the V/6 ring, due to variation in ballistic coefficient and variation in additional induced drag due to non-concentricity, this is with the rifle in a machine rest without any external variations included.
Spinning for conformity and concentricity is the most effective way to eliminate as much as possible the variation in the ballistic performance of modern rifle projectiles, missed by every other method.
We still highly recommend refinement on the points mentioned above after spinning, i.e. measuring for length, which addresses other factors that are critical but have little direct impact on identifying variation in drag.
"What's One Point Worth?" It's all in the 1%