How much bigger, is the Dovetail on the Itailan made rifles over the std.

[Ace Lungger]

Howdy guys,
Can anyon give me a close size differnt between the Normal 3/8ths dove tail rather than the metric Italian Dove tails. I have a Lyman 17au front sight with a 3/8ths dove tail and I want to use it! If someone has a Italian dovetail sight, I would be great full if this person could measure in mm, the small and large ends, and then I was place it on a peice of brass and then use another peice of brass as a guide, then mig on a small bead all the way down the front side and mill it to specs!
If any one could give me those measure ment I would be great full!
Thanks ACE

[Pettifogger]

Every Italian copy of a Winchester or Colt Lightning that I have ever seen has had "standard" 3/8" dovetails.  In fact, about the only commonly used cowboy gun that doesn't is the Rossi and that's made in Brazil.  Now the problem is the "standard."  The sights and the dovetails all vary a little (some actually quite a bit) from the "standard."  In order to fit sights you should have a sight dovetail file.  It is smooth on two sides and has only one cutting edge.  You always fit the sight to the BARREL.  Never remove material from the barrel (unless, for example, you are dressing up a damaged dovetail) always from the sight.  Sights are cheap, barrels aren't.  If you don't have a slight file, you can grind the teeth off two sides of a regular fine tooth three sided file.

[Ace Lungger]

 Pettifogger ,
Thanks for the advice. My IAB Sharps has a metric dovetail, I have read other places, about this, and I also think the pedersole has the metric dovetail. i bought the IAB creedmore sight system, and the front sight fits great, but the Lyman sight will move around. I will just have to play with it.
Thanks ACE

[Pettifogger]

Just take a Coke can and cut it into strips the width of the bottom of the dovetail.  They make dandy shims.

[Coffinmaker]

Or, if it's too close for a shim but still a bit "slidy," you can slather it up with a little LocTite.

Coffinmaker