Sight File Question

[Long Ears]

What type of file do you guys use to cut the dovetails for your sights and lugs? I safe sided a 3 corner file but it is still rounded at the corners. I see Brownells sells a 65 degree sight file. would it be better? Thanks, Bob

[Jerry V Lape]

For what Brownell charges for that file it should be much better! 

[Dave Faletti]

How much rounding are you talking about?  I have the Brownells file(cost too much) and it does fine.  A dovetail cutter on a mill is going to give the best cut.  As long as there is a decent amount of material it will hold fine.  The straight section of the sloped surface should be much longer than the length of the rounded corner if that makes sense.  Need a pic.

[smylee grouch]

Brownell sells a fine single cut and double cut straight sided three corner file(parlell)sp.    They are worth the money if you have alot of dovetailes to do as they will help in keeping the cut straight.   

[B.Habermehl]

Carefull grinder work on the safe side of your file will result in reasonably sharp corners. Just keep the file cool.  when the file corner dulls, grind the safe side down .015 or so, presto new sharp teeth. Back when I started this hobby(obsession) I couldn't afford to even think of paying Brownells price for a dove tail file. I still never have 20 years later. Cast sights sights don't have all that sharp of corners any how, Only really neatly hand filed or machined sights will have sharp corners on the dove tails. I usually dress all of these back just a bit to a .010-.015 radius or so, rather than deal with a sharp burr edge. Neat matching of the dove tail and sight means much more than a sharp corner in a dove tail.

[D. Taylor Sapergia]

BJH's advise is good.  Just keep grinding until you have very sharp edges, and all of the teeth are gone on the safe side.  Without those fine sharp teeth on the edges, it is hard to keep the file cutting flat...it will want to cut uphill or down hill, and it's difficult to see it 'til it's too late.  Even with a file like this, I gently round the corners of the sight's base so that it does not shear metal as I tap it into the dovetail.
There's a tutorial in that forum on cutting dovetails for underlugs, but it applies to sights too.

[Lucky R A]

   So why don't you do it like the old boys did.  Cut your dovetail a bit undersize and then put a cold chisle in the corner and raise a hump on the outside of the barrel, slide your underlug into place, then set the hump back down to pin the underlug into place.  It is very fast easy to do, requires no special expensive files, and is more secure than a filed dovetail.  This also works very well for setting rear sights, just don't punch down the hump until the gun is sighted in.  Do not use this method for front sights as the blade of a front sight has to set tight down on the barrel.  K,I,S.S.

Ron

[Blacksmoke]

Like Taylor says: Keep grinding one flat on the file till the edges on the 3 corner file are nice and sharp.   However remember to only grind a little at a time so as not to heat the metal too much - which will anneal your file edges and render it useless.  Keep dunking the file in water after each grind to keep it cool.         Hugh Toenjes

[Daryl]

Ron- there is a specifically ground chisel for doing sight notches - think track sells them- probalby not expsnive. I did one that way, but being a GM barrel, less than butter soft, the end result didn't match the originals done on soft iron, although it did work.  12L14 is soft enough to work well with a chisel.  Taylor's little .40 J. Kuntz rifle is testimony to that.

[Lucky R A]

  You are right Daryl, I have one cold chisel sharpened with one bevel only just for doing rear sights and underlugs.  G.M. and Rayl barrels are a bit on the hard side, but you know the old saying--"Get a bigger hammer."
Ron

[Jim Kibler]

Ron- there is a specifically ground chisel for doing sight notches - think track sells them- probalby not expsnive. I did one that way, but being a GM barrel, less than butter soft, the end result didn't match the originals done on soft iron, although it did work.  12L14 is soft enough to work well with a chisel.  Taylor's little .40 J. Kuntz rifle is testimony to that.

Are you are refering to the chisel type tool that is set flat on the barrel and struck to form a dovetail?  I've seen these advertised, but would have no desire for such a tool.  Can't imagine it would work well.  Besides being awkward, I would fear with such little downward pressure, the chisel would have a tendency to raise up while forming the dovetail.  As Ron mentioned, a simple cold chisel ground to a slightly lower angle works perfect and provides all the control one would want. 

[whitebear]

I have one of those fancy dovetail chisels, when I started I thought I had to have everything to make the job easier, but I have never had any luck with it.  When I hit it with a hammer it just jumps out of the slot no matter how I hold it.  I even tried taping it down.

[fm tim]

I concur with Mr. Kibler and Whitebear.  Device is difficult to use.

[JDK]

I was at Big Lots a while back and found the Stanley "Short Cut Saw Sharpening Kit" item number 22-434.  It is marketed on cardstock and contains a guide for sharpening the saw and a straight triangle file with one side safe.  It file has very sharp corners and cuts steel like butter as it meant to cut saw teeth.  Leaves a perfect dovetail undercut.  They still list at on the Stanley Tools site at
http://www.stanleytoolparts.com/22-434-1-02-0d-0.html for $9.94.  At that price it's worth a try.  You may be able to find it cheaper elsewhere.  It was much cheaper at Big Lots but I have never seen it there again....of course.  Enjoy, J.D.K.