The Lil Gun powder is very efficient in the little hornet case, in my gun Ruger 77 Varmint 22 hornet I shoot a 40 grain Sierra HP, flatbase over 12gr of lilgun. It is a very safe powder to use i don't believe you can put over 13 grains in a case without compressing them. Also 13 is the max, just load up from 11.5 thru 13 in 1/2 grain incriments and I bet you will find a load for your gun.