How are dovetail sights sized?

Discussion in 'Technical Questions & Information' started by Dutchboy, Jun 7, 2010.

  1. Dutchboy

    Dutchboy Member

    Jun 5, 2010
    I've got a Rossi R22B (2001 vintage). It's a .22 single shot rifle with a dovetail slot for a rear sight. The existing rear sight is plastic, and pretty beat up. I'd like to replace the rear sight with a newer and nicer one that's adjustable for elevation and windage.

    I was thinking of something like what's on my 10/22, but that sight is getting hard for my older eyes to see. I'm not ready to give up (yet) and go to actual optics. I'd like to stick to iron sights if I can. Call me old fashioned. . . Or maybe just stubborn.

    Any suggestions about what I should buy for a rear sight for this rifle?

    How are sights sized? Are the dovetails all certain sizes? How is the height determined?

    Any suggestions and information would be appreciated.
  2. yes dove tails are is difficult to measure though so it would be better to contact rossi to find out the correct do not want to attempt to install the wrong size you could mess up dovetail.when installing you must be very careful to start it straight.i would dif suggest replacing as a set,that way they will match and still be adjustable.i generally replace mine when needed with williams sights,they have a web sight that you can order and choose from...................old semperfi

  3. Big Shrek

    Big Shrek Well-Known Member

    Nov 10, 2009
    NorthWest Florida
    A digital Micrometer should easily measure your dovetail.

    And here's what I'd replace 'em with...

    Skinner Barrel-mount Sight

    Or a Marbles Bullseye Sight...

    Both great, both zero-headache, and help older shooters by virtue of being a peep sight.

    With dovetail sights, you simply file the Sight, never the dovetail...and they shouldn't be forced other than a few love taps with a brass punch & hammer. Gentle force...if it doesn't go in, file the sight.

    Something made in 2001...should be a normal 3/8" / 9.5mm dovetail.
    Rossi tends to be fairly regular, as mentioned above, it's helpful to call them direct.
    Last edited: Jun 8, 2010
  4. Dutchboy

    Dutchboy Member

    Jun 5, 2010
    Thank you for the great information and ideas. I'll follow these leads.
  5. Dutchboy

    Dutchboy Member

    Jun 5, 2010

    Called Rossi with Model and serial number information. The lady on the phone told me that in the past, Rossi used non-standard dovetails. She thought that mine was new enough that it would have a standard 3/8" dovetail, but she was not sure, and she would not guaranty it. She also said that there was no way to check Rossi's records to find out for sure.

    Wrote to Marble Arms. The fellow there confirmed that Rossi rifles can have non-standard dovetails. They tended to be wider, and have a shallower angle. The standard angle would be 60 degrees.

    So, I'm going to borrow a nice micrometer and see if I can figure out what I've got on my particular Rossi rifle.
  6. Big Shrek

    Big Shrek Well-Known Member

    Nov 10, 2009
    NorthWest Florida
    Digital Micrometer - $10 at Harbor Freight Tools stores...less when on sale ;)

    Usually under $20 anywhere else...

    You find that you use them a lot once you get one...very handy for measuring small parts of all sorts :)
    And not just gun parts, handy for Motorcycles & cars/trucks/SUV's as well. :D
  7. JLA

    JLA Well-Known Member

    Feb 26, 2007
    Heart Of Texas
    If I remember right the older rossis had some damn wide dovetail sights. I pray you have the newer 3/8. the older ones are near impossible to find...
  8. Dutchboy

    Dutchboy Member

    Jun 5, 2010

    I checked out the dovetail with a caliper, and I confirmed that it was a standard size.

    So, I bought the Marbles Bullseye Sight from Brownells, and I installed it on the rifle yesterday. It fit in the dovetail perfectly. That sight is a huge improvement from open sights. I could hardly use the old sights with my old eyes. Now, I feel like a regular sniper (only with an single shot 0.22 :))

    Thanks for the help, and for the good advice.
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