I don't know about the 30deg. angle, but S&W front sight blades come "undrilled" because the older guns might have them drilled within a range on the ramp. (not all were drilled exactly the same).
I suspect you have an early Sec.6. Either way, you'll need to drill the hole in the front sight blade to match the ramp.
It may be a bit difficult if angle really is 30deg.
Most of the time this is done by tapping the sight into place, clamping the barrel into the cross-slide on a milling machine or drill press and running the bit into the old pin hole and use it as a guide to drill through the sight. Then, the appropriate size roll pin is drift punched into the hole.
I had a similar situation with a 4" Sec.6 that I bought several years ago. Only, the front sight was just real loose. I ended up using "Super Glue" as a fillet media and used a cloths pin to hold the sight in vertical plane till the glue harded. I've fired several hundred magnum rds, and many hundred .38spl rds and sight is still tight.
This gun is my favorite "truck" gun, and has accounted for several pigs while I was other wise squirrel, or other small game hunting with long gun inappropriate for PiG's.
BTW; A 165gr SWC-GC @1,300fps did wonderfully!
I picked this gun up for a "song". It was on a table at the NPSC, and nobody was interested because at the price, "something HAD to be wrong with it"!
Turned out to be one of the best deals I ever stumbled onto.
Don't try drilling by hand, you'll either bugger the hole, or worse, break off the bit in the hole.
I suggest having a gunsmith familiar with front sight handgun work do this.
It would probably be money well spent to send it to Mr. Gallagher in Jasper, AL. He's the best I know of.
Good Luck!!
