Sako S20 Optilock 20 MOA mount: review

ptosis

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After the initial joy of owning a magnificent new Sako S20 rifle, comes the awkward "I should have taken a Tikka" moment – this is when the new owner inspects the optics mounting rails.

There is a problem with the original bits of picatinny in front and behind the ejection port. Actually, three problems:
(1) They have no inclination, it's 0 MOA flat = half of your scope adjustment range is useless, which means that for most scopes and calibres you don't have enough clicks to shoot beyond 800 m or so without counter-aiming. Two distant segments of Picatinny (rather than one long rail) make it impossible to use a single-piece mount to fix the issue.
(2) The rear rail segment is rather close to the eye. For scopes with a long ocular part (e.g. S&B PMII 3-20x), the eye relief is too short for comfortable shooting.
(3) They are machined with the receiver, and cannot be replaced easily.

The Optilock mounting base is therefore primarily a way for Sako to earn easy money by fixing problems that they have created in the first place (btw, the rings that go on the Optilock base are, of course, totally proprietary, and need to be purchased with the base). This said, the fix is perfectly efficient. Machining and quality are expectedly flawless, the inclination is there (I took the 20 MOA version; Sako documentation also mentions a 30 MOA version, but I have never seen it IRL), the added height and weight are very reasonable, and the positioning options allow to accommodate pretty much any scope – with longer or shorter oculars. Mounting instructions are clear, and specify recommended torque values for all screws (and, unlike the Spuhr ISMS manual, are consistent between in/lbs and Nm units).

sako-s20-ol-mount.jpg


All in all, it works out very nicely. The "medium height" 34 mm rings set the optics axis height at about 5 cm above bore axis (vs. ~4 cm with low B&T rings directly on the receiver). There is largely enough space to accommodate up to 56 mm objective lenses with a heavy 6.5 CM barrel (pictured above with a x50 scope). Ejection is clean.

After a few "settling down" shots to get all the elements of the mount to find their resting place, the performance is as expected – between 5 and 8 cm max spread on 5 shots at 300 m (= 0.56 to 0.90 MOA) with factory Lapua ammo.

IMNSHO, way to go.
 
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After the initial joy of owning a magnificent new Sako S20 rifle, comes the awkward "I should have taken a Tikka" moment – this is when the new owner inspects the optics mounting rails.

There is a problem with the original bits of picatinny in front and behind the ejection port. Actually, three problems:
(1) They have no inclination, it's 0 MOA flat = half of your scope adjustment range is useless, which means that for most scopes and calibres you don't have enough clicks to shoot beyond 800 m or so without counter-aiming. Two distant segments of Picatinny (rather than one long rail) make it impossible to use a single-piece mount to fix the issue.
(2) The rear rail segment is rather close to the eye. For scopes with a long ocular part (e.g. S&B PMII 3-20x), the eye relief is too short for comfortable shooting.
(3) They are machined with the receiver, and cannot be replaced easily.

The Optilock mounting base is therefore primarily a way for Sako to earn easy money by fixing problems that they have created in the first place (btw, the rings that go on the Optilock base are, of course, totally proprietary, and need to be purchased with the base). This said, the fix is perfectly efficient. Machining and quality are expectedly flawless, the inclination is there (I took the 20 MOA version; Sako documentation also mentions a 30 MOA version, but I have never seen it IRL), the added height and weight are very reasonable, and the positioning options allow to accommodate pretty much any scope – with longer or shorter oculars. Mounting instructions are clear, and specify recommended torque values for all screws (and, unlike the Spuhr ISMS manual, are consistent between in/lbs and Nm units).

View attachment 300331

All in all, it works out very nicely. The "medium height" 34 mm rings set the optics axis height at about 5 cm above bore axis (vs. ~4 cm with low B&T rings directly on the receiver). There is largely enough space to accommodate up to 56 mm objective lenses with a heavy 6.5 CM barrel (pictured above with a x50 scope). Ejection is clean.

After a few "settling down" shots to get all the elements of the mount to find their resting place, the performance is as expected – between 5 and 8 cm max spread on 5 shots at 300 m (= 0.56 to 0.90 MOA) with factory Lapua ammo.

IMNSHO, way to go.
Do you think just medium rings would be good for the 50mm scope on S20 (without optilock) or should I go with high rings? I'm planning to put Burris xtr rings.
 
Hi Ptosis, so you used 34 mm ( MEDIUM) rings with a scope having a 50 mm bell objective and there is still enough space for a 56 mm objective. My scope has a 30 mm tube diameter with 56 mm bell objective, do you think I can also use MEDIUM rings too? Thanks in advance
 
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