Photo of Bryan Litz (on the right) and Mitchell Fitzpatrick, tester. Bryan stated that there are only 2,445 rounds left. We are testing over 50 types of ammo in five twist barrels… science can be exhausting!” Do we know the BC (Ballistic Coefficient), of your rimfire ammunition. Applied Ballistics has all the information thanks to a marathon ammo testing session. Bryan Litz and his team from Applied Ballistics conducted an extensive shooting test to determine the “real-world” BCs for various rimfire ammo types. Litz and his company tested more than fifty types of.22 LR ammunition using five twist-rate barrels. This was one the most thorough and comprehensive rimfire ammo testing ever done. Bryan explained to us that he had tested many types of.22-rimfire ammunition for the latest edition of Ballistic Performance of Rifle Bullets. We used Oehler chronographs (MV and 100 yard) to measure velocity at the muzzle (MV). Bryan can then calculate G1 BCs for all 50+ types of rimfire ammunition. Bryan can also determine the effect of twist rate on velocity because each sample is shot through five different barrels. These tests are used to calculate BC calculations, not accuracy. Bryan explains that accuracy is not something we test because it’s subjective to different rifles. Our testing focuses primarily on measuring the BC for rimfire rounds from different twist rate barrels. The upcoming second edition of Ballistic performance of Rifle Bullets will publish the MVs and BCs of the different twist-rate barrels. Science and the Rimfire Universe:
Bryan’s goal was to expand the rimfire knowledge base. “We hope that the world of.22 LR rimfire will get a good dose science.” How does barrel twist affect the BC of.22-rimfire ammo? Are subsonic rounds more consistent than transonic or supersonic rounds? Which brands have the highest BCs Which brands have the highest MVs?
Two Oehler chronographs are used to record data in a computer. Five (5) different barrels were used to test the ammo samples. Each barrel had a different twist rate. Dane Hobbs provided a test rifle, multiple barrels and most of the ammo for the test. .22LR at 300 yards?
Bryan also did some rimfire tests at longer ranges. His fascinating findings were published in the Modern Advancements in Long Range Shooting book series. Bryan writes: “While.22 rimfire may not be considered ‘long-range’, we were able consistently hit a 2-MOA steel target at 300 meters with the trajectory predicted using AB software and the BC of standard.22 LR rimfire ammunition. We may be able to increase the range of target engagement for a round with the information we are generating. This is something that has not been possible in many decades.
