Cutting a New Rear Sight Dovetail?

[Ohvall]

If you have an "oddball" pistol with few aftermarket sight options, is it possible to weld up the original rear sight cut and mill a new one?  Or, if you want to mount a Bomar-style target sight are you just going to remove most of that metal anyway?

[MikeBurgess]

50 minutes ago, Ohvall said:

If you have an "oddball" pistol with few aftermarket sight options, is it possible to weld up the original rear sight cut and mill a new one?  Or, if you want to mount a Bomar-style target sight are you just going to remove most of that metal anyway?

it all depends

yes you can weld and re-cut slides for sights, but some guns have slides with parts that may get in the way of some sight cuts, so you have to take some good measurements before you start. I think the largest reason you don't see more of it is for a smith to weld, mill, fit , and refinish a slide is near the cost of a new gun that doesn't need all that work.  

[assaulter]

You are likely going to remove .100 from the top anyway.

[RJH]

IDK what gun you have, but another option might be to find a sight with a too large dovetail or whatever it is called and file it down to fit in your slide

[Ohvall]

The pistol I have is an FN FNS-9 5".  It has a wide, shallow dovetail for the rear sight, so filing down the base of a sight made for another pistol probably wouldn't work.  But since it's the same basic design as the FN 509 and FN puts some deep optic cuts into the 509 Tactical/MRD slides I think there's a good bit of metal there.

 

This would wind up being a bullseye pistol for CMP matches so a low mount isn't a priority.  I'd be fine with something sitting high and hanging off the back of the slide.

[RJH]

1 hour ago, Ohvall said:

The pistol I have is an FN FNS-9 5".  It has a wide, shallow dovetail for the rear sight, so filing down the base of a sight made for another pistol probably wouldn't work.  But since it's the same basic design as the FN 509 and FN puts some deep optic cuts into the 509 Tactical/MRD slides I think there's a good bit of metal there.

 

This would wind up being a bullseye pistol for CMP matches so a low mount isn't a priority.  I'd be fine with something sitting high and hanging off the back of the slide.

 

 

I think the CMP service pistol matches require fixed sights, but IDK which event you are wanting to shoot.  That said Warren makes some nice ones and so does Heine.  Also the Heines list the fn 509 and sig 320 as the same sight, so sig 320 sights look like they might fit your gun and that might give you more options

Edited June 4, 2020 by RJH

[Ohvall]

The CMP runs several types of matches.  I shoot the service pistol matches that are shot at 50 and 25 yards so everyone uses adjustable sights.

 

Although the FNS and 509 are very similar, the FNS uses a proprietary rear dovetail.  FN must have realized that was a bad idea because they switched to the P320/XD style sight cuts for the 509.

 

If FN could just make a 5" version of the 509 I'd buy that but I doubt that is going to happen. 

[WhiteDingo]

Cut the rear dovetail to a flat pocket and solder/braze in a Bo-Mar style base, or something like the Wilson no dovetail sight 

https://shopwilsoncombat.com/Lo-Mount-Adjustable-Rear-Sight-Standard-Blade/productinfo/428W/