A buddy of mine gave me a dozen of these brand new. They fly good and get amazingly sharp with just a little Arkansas stone. Which model is this head? The 1 or 2 ?   Does anyone still use them, they seem to be a great broadhead.  

I believe that is a magnus 1.  135 gr.

I did weight them. 6 are 135 and 6 are 145

I am using the 135 with adapter.

A good broad head. I wish they were still being made.

Same ESP...I used to get them insanely sharp

Yep - that's a I.  The II has deeper angle to the trailing edges.

I use the 160's and fortunately bought up a stash before they went out. Always have an eye out for more but they are scarce now.

Your 145's are probably the ones that came out later as 160's.  Those never did make weight.  But both are very good heads.

I am pretty sure the 135 was the first, or at least one of the first heads Magnus ever produced.

Some years before Magnus sold them off, they dropped the "I" off the name but everybody still called them that anyway.

I have quite a few still on arrows and one unopened pack of the 4 blade version still.     :D