Bontok 11mm Dovetail to 21mm Upgraded Build-in Locking Screws Picatinny Rail Low Profile Scope Mount Converter Base 3/8" to 7/8" Converter

Good quality; fits precisely and solidly on my dovetail; allows the Picatinny rail to readily accept the sight mounts.

I purchased this with the intent of modifying it to fit on a 760 Pumpmaster pellet gun. Since it had a rounded receivers, and since you cannot put any clamping force on the rear section of the receiver, doing so clamps the BB loading tube closed so no BBs can go into it. This mount was hopefully going to clamp only on the front rail and not touch the rear at all. First thing necessary is to use a good size rat-tail file to make a suitable concave run in the bottom of the mount with a contour matching the contour of the top of the 760 receiver. Next, file the bottom rear corners off so that the do not touch the front of the rear receiver dovetail. Only need to take a little off there. With that done this mount fits snugly and now has a Millet red dot on it. I only used the front and middle screws on the mount. I put the rear one in but for looks only, the front and middle screws are more than sufficient to hold the red dot on a BB/pellet gun. Well worth the effort. This combination is giving me BB groups at 20’ less than a dime. Why 20’, it’s a BB gun, not my 1600fps high end pellet rifle. So, if you have a rounded top BB/pellet rifle/gun, and want to put a scope or red dot on it, and am a little handy with a file I highly recommend this base over the bases that have only two clamping screws.

This part saved me from an expensive gunsmith bill. Worked great!

Despite what the photo shows, you only get one of these with your order. Not that I necessarily needed two, but it’s bad form to advertise two in the listing’s main photo. It’s a decent mount otherwise and fits well on my Gamo Urban. Not worried about recoil so this thing is pretty solid for my purposes. Attaches easily but make sure you keep it level on both sides of the dovetail otherwise you’ll notice a slight cant in your optics when you go to shoot.

Fits perfectly on my air rifle. Excellent materials and machinery, especially for the price point.*

Was better than expected. I'm a 30 year gunsmith. Machining almost perfect. Finish really good for flat. Big compliment from an old Smith.

Fast and easy install. Fit very secure. Very clean look. Won't move after secure providing accuracy with any scope.

Works great, very sturdy and seems tough, definitely buying again if needed in the future.