I am having problem finding loading date foe the 4166 IMR. has anyone worked with new powder. I am trying to get date for 223 rem. with a 77gr. sierra mk.Any imput would be very helpful. thank you. bpranger

I would suggest calling Hodgdon. They are very nice people and will be glad to discuss this with you.

try their web site.

http://www.hodgdonreloading.com/data/rifle

IMR 4166 .224" 2.260"
19.9 2,452 - 45,200 PSI
22.0 2,663 - 53,600 PSI