The .14 hornet as you can assume is based on the .22 hornet case. It is necked down and the shoulder blown forward and straightened out. The .14/221 is based on the .221 fireball case, necked down and slightly blown straight. Bullets range from 10g to 17.5g with velocities running on avarage 3800 for the Hornet and 4100 for the .14/221. The barrels we are having built will handle all the range of bullet weights, however the hornet does better with the light weight bullets and the 14/221 does well with all of them, the 12g having the advantage of being pushed to about 4300. Bullets and supplies are available from us as well as other suppliers, none of the majors like Rem, Win, Sierra, Hornady, etc are making .14 cal bullets. The bullet dia. is .144. effective range depends on the target, for the smaller prairie dogs I'd say about 200yds, I can say that from 100yds with a 15g in the .14/221 they are completely misted. It is a very fun little caliber, it is best suited to those who are into very precise loading and shooting. In the hornet case especially very minor changes will create a big difference when the trigger is pulled. For fur shooters they are a great round, they provide a very very small entry hole and a complete blow-up on the internals, no exit. One of these days I will get some pictures done, but for now we are so busy with orders (everything else) that it is all I can do to keep up.