Bedding a Rifle Scope

A how-to on bedding a rifle scope is a bit of an odd first post for our Defenses category but it happens to be timely.  I recently purchased a new long-range rifle and I’m getting ready to install my first one-piece scope base.  So, I’ve been doing a bit of research on the best way to fit a one-piece mount to a Remington 700.  If you’re not aware, the 700’s are somewhat notorious for relatively poor receiver tolerances making one-piece mounts more difficult to install.

For my installation, I’ve chosen the Badger Ordnance 20 MOA base pictured below.

Badger Ordnance 20 MOA Base

Frequently, you’ll end up with vertical stringing in your groups if you install a one-piece base without proper bedding.  You’ll also place unnecessary stress on your rifle’s receiver as well as the mount.

Not every base will need to be bedded.  How do you know if yours does?  How do you know which end needs to be bedded, if not both ends?

Determining Whether Bedding is Required

  1. Place the scope base on top of your rifle’s receiver
  2. Tighten the screw(s) on only one end of the base (do not over-tighten)
  3. Utilizing a .001″ feeler gauge (pictured below) check for a gap on the loose end of the base
  4. If the feeler gauge slides under the base, you have a gap that needs to be bedded
  5. If no gap is identified on the first end of the base, repeat Steps 1-4 for the opposite end of the base
  6. The end of the base with the gap needs to be bedded.

    Feeler Gauge

Once you have determined whether or not your scope base needs to be bedded, the bedding process is fairly straight-forward.

Bedding a Scope Base

  1. Thoroughly clean the under-side of your scope base and top of your rifle action with an acetone or alcohol-soaked cloth (I prefer a lint-free cloth to avoid leaving any fibers behind after cleaning)
  2. Do not touch these surfaces with your bare hands once you have cleaned them (you may want to use Nitrile gloves for the rest of the process)
  3. Apply a liberal coating of release agent to the scope base mounting screws
  4. Mix the appropriate amount of bedding compound according to the manufacturer’s directions
  5. Insert all of the scope base mounting screws into their corresponding holes in the rifle’s action; tighten 1/4 turn
  6. Apply a thin layer of bedding compound to the under-side of your scope base and around the screws in your rifle’s receiver (any excess will be cleaned off in a later step)
  7. Remove the screws from the rifle’s receiver
  8. Place the scope base, with the bedding compound on it, on top of your rifle’s receiver and begin to tighten the two center screws
  9. Tighten the two center screws until the base appears to be in contact with the rifle’s receiver (you can utilize the feeler gauge again to ensure contact; do not over-tighten the screws)
  10. Tighten the outer two screws until they make contact with the scope base (the torque of the inner and outer screws should be the same at this point)
  11. Wipe off any excess bedding compound with a clean cloth
  12. Clean up any excess residue with acetone-soaked cloths or Q-tips
  13. Bedding compound may continue to seep from under the scope base for an hour or two; be prepared to repeat Step 12 as it does so
  14. Once the seeping stops, set the rifle aside and allow the bedding compound to cure according to the manufacturer’s instructions
  15. After the bedding compound has cured, torque all four screws to the manufacturer’s specifications and go shoot your rifle!

Plan | Prepare