Wednesday, August 27, 2008

Benjamin 317 "Bar-V" Sight Locknut

Since I resealed the Benjamin 317, there's been one little detail left to finish...

The "Bar-V Rear Sheave Sight" is supposed to have a lock nut, not a cheap looking hex nut. So as I thumbed through my copy of DT Fletcher's "The St. Louis & Benjamin Air Rifle Cos" book, I found a few line drawings of the nut in various advertisements that conveyed how it should look.

Drilling some 1/4" stock for a #4-48 tap.

Straight knurling. Notice my crude knurling tool. This isn't ideal on the Taig lathe, due to the force needed. But I didn't feel like setting up another tool on my South Bend.

Tapping the nut.

Parting off. Usually for parts like this I'll hit the outside edge with a file to chamfer, then part halfway through, hit the inside edge with the file, then finish parting off.

Screws right on.

I hit it with some "perma blue", which is neither perma nor blue...

Of course I decided to search for the patent on this sight, and found it, so I may have to see whether the production sight used the toothed spring washer described in the patent.

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