Skeeter 7mm, I use the 250 gr.sst and 2 50 gr. 777 pellets.Very accurate killed 5 deer with them last year(they give doe tags out here in NY like candy on halloween)excellent performance,shots ranged from 30yds to 125 yards.I plan on working some more with the load,I now have some 30 gr. pellets as well as shooting loose 777 2f,but I have been working on my elk load for up coming hunt in Co.this Sept. 95gr.777 2f and 405 gr.powerbelt also excellent accuracy.Good luck