Your Hill's Hornet seems to be a 'sloped shoulder 3-bld' - either 5/16" or 9/32". The later will have a ferrule about 1.16" in lenght the former one of 1.43" - and thats what I would guess it is. I have one in my collection like it. Yours also looks as if resharpened several times.
It dates back to c. 1950 and was made by Ralph Hill from Racine, Wisconsin. About 20 different makes are known of Hill's Hornet heads. Rather low collectors value if you should want to know that?! But any old broadhead is nice, not :D