Match the model to the published BC. Shape is a visual guide only—the same projectile can have different BC values for different drag models.
G1
General rifle bulletsCommon for traditional hunting, varmint and general-purpose rifle bullets when the BC is published as G1.
Reference shape: shorter rounded ogive with a flat base.G7
Long-range boat-tail bulletsCommon for modern match and very-low-drag rifle bullets when the BC is published as G7.
Reference shape: long pointed ogive with a tapered boat-tail base.GA
Diabolo airgun pelletsFor air rifles and air pistols using Diabolo pellets when the BC or data source specifies GA.
Shape: rounded head, narrow waist and flared hollow skirt.Strelok APK: Chairgun GA retardation table for Diabolo Airgun Pellet.RA4
.22 LR rimfire bulletsFor .22 LR ammunition when the BC or data source specifies RA4.
Typical shape: rounded nose, short body and a small heeled base.Strelok APK: For 22LR bullets.Reference note: GA and RA4 descriptions follow the attached Strelok APK; G1 and G7 sketches show their standard reference projectile profiles.