I use core lokts in my 7mm mag. I also use 150 grain bullet. I have not had a problem with them. I used to use Winchester Super X, but the past two seasons I have used the core-lokts, and have had good luck with them. I did have a double lung shot on one last year that knocked the lung out of the back of it, and there was not much blood. The deer ran for 20 yds, and very little blood. I just think that sometimes lung shots do not produce a lot of blood.