(8-40 stainless screws available upon request). Hole Spacing (From Rear): 1st to 2nd: 0.607' 1st to 3rd: 4.242' 1st to 4th: 5.100' ** Each base ships with 6-48 alloy steel Torx screws, and a T15 Torx wrench.the problem none of these line up with the pre drilled mounting holes in the receiver. I purchased all three red field mounts short, long, and xtra long, and one weaver long action. I'm having a problem trying to find a one piece scope base for a Remington model 788 308 win. Shiloh Front Ring Set (specify size) N/A All models need four holes drilled and tapped on barrel RIFLE New Side Sharps Mount Front SHSMT Old style distance between screw holes is ~0.825' (included w/scope) and new style distance is ~0.860' (HPMOUNTSET - buy separately). specify center-to-center screw hole distances to get correct scope bases.If you have a question, please go to our “ Ask Dan” page. Note: If you need custom bases here is a good source. Install base with the 1/2 moon radius to the clamping screw side for Original Style. NOTE: Install base with the square notch to the clamping screw side for Posa Style (this is the best style). 17.0” 1/5 minute per line (.001”) 80 minutes of elevation.10.8” 1/3 minute per line (.001”) 133 minutes of elevation.7.2” 1/2 minute per line (.001”) 200 minutes of elevation.Sight Radius: Minute of movement per line (.001”): Below is the Unertl base separation chart (sight radius).Make sure to have the (square) notch on the right side so the locking screw will fit in the notch.Installation of these mount is accomplished by using Posa style bases (square notch).If at all possible use an 18″ scope to achieve the shortest sight radius.The picture shows the front and rear mounts with an original Unertl (Posa style) mount on the right side. This means you can adjust your scope for wind and mirage changes without “holding” to try and compensate for the changes. What are Universal Mounts? These mounts will install on “Original or Posa” style bases. Malcolm Style 8 Power Scope W/Universal Mounts. These are a copy of a Universal (Posa/Original style) mounts with an additional. Here is the scope mounts you have been waiting for. Arms Custom Universal-Style (Posa/Original style) Mounts NRA Approved and Designed to fit all 3/4″ Scopes including MVA

Unertl scope base chart