I am having a dispute with my head coach regarding proper tackling technique. I thought proper tackling technique involved having the head across the chest with the shoulder in the thigh or at least somewhere below the chest and the wrapping up. My head coach teaches it the old school way which involves putting the facemask in the chest and then wrapping.

I was told the facemask in the chest technique is at the least illegal and at the most dangerous.

Please give me some information regarding this coaches.

Head goes to the v of the neck, wrap arms and drive threw the contact.

From what I am seeing your Coach is in the dark ages and he's not alone. There are ex-NFL people who are on his side. But, ultimately you are correct on both fronts.

Am A Coach - Pop Warner 6 years.
Facemask in the chest, I have had to many young kids hurt their neck and shoulders if it is not done properly. I have been instructed by our high school coach (Division 1 High School State Champions 2 years running), to have the kid look straight at the ball carriers belly button (this also has them focus on not getting faked out by leg, head and arm movements) and drive with the shoulder pads into the thighs and then wrap the arms. A sure tackle almost every time.