Comments on: Do Chron Your Factory Ammo — Stated Velocities May Be Wrong https://bulletin.accurateshooter.com/2022/05/do-chron-your-factory-ammo-stated-velocities-may-be-wrong/ from AccurateShooter.com Thu, 30 Apr 2026 14:59:33 +0000 hourly 1 https://wordpress.org/?v=4.1.26 By: westie https://bulletin.accurateshooter.com/2022/05/do-chron-your-factory-ammo-stated-velocities-may-be-wrong/comment-page-1/#comment-60515 Thu, 05 May 2022 20:23:00 +0000 http://bulletin.accurateshooter.com/?p=65782#comment-60515 Great article.
A friend of mine has been chrono’ing a lot of factory ammo as part of barrel tests. What I’ve noticed is that the SD depends a lot on sample size. I’d expect a 5 shot group to have an SD about 15 percent less than the true SD. What sample size is your table built around?

Another interesting trend we saw is that the first shot is generally faster. About 35 percent of the time it’s the fastest in a 10 shot group. Are you including the “cold bore” shots or tossing them?

Podcast is great, I’m slowly working through them!

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