In Stock Spuhr ISMS ST-6401 Ø36mm Tube 4 MIL (30mm High) Sako TRG Scope Mount
"For shooters running European dovetail actions, this 36mm Spuhr mount delivers both elegance and serious long-range capability. The built-in 14 MOA cant gives you valuable elevation without compromising optical centering, making it ideal for precision hunting and long-range target rifles. As always with Spuhr, the machining and alignment are second to none — this is a premium mount for premium rifles." - Thomas (Online Sales Associate & Product Specialist).
The Spuhr ISMS (Ideal Scope Mount System) is a high-performance mounting solution engineered for shooters who demand unmatched stability, precision, and modular versatility. Its single-piece, billet-machined aluminium construction provides exceptional rigidity, virtually eliminating flex under recoil and ensuring repeatable zero for long-range, tactical, and competition applications.
The system’s diagonally split rings give unobstructed access to elevation and windage turrets, allowing fast and precise adjustments without interference. An integrated levelling system and alignment wedge ensure the optic is perfectly level during setup, critical for extreme-range accuracy and consistent shot placement.
Multiple interface points along the mount allow secure attachment of a wide range of accessories, from lasers and rangefinders to backup optics and night-vision devices, without affecting rifle balance or ergonomics. Machined from aerospace-grade aluminium and finished with hard-anodised coating, the ISMS offers exceptional durability, corrosion resistance, and mechanical integrity under heavy recoil and field conditions.
With its combination of precision machining, modular functionality, and rock-solid strength, the Spuhr ISMS is designed to elevate any rifle platform, providing a foundation for accurate, repeatable, and adaptable long-range performance.
Ring Height - 30mm
- Ring Size 36 mm
- Tilt 4 MIL / 14 MOA
- Height 35 mm / 1.38"
- Clearance 6 mm / 0.236" (from bottom of tube to bridge of mount body)
- Length 126 mm / 4.96"
- Weight 245 g / 8.6 oz
- Interfaces 7 sets
- Material 7075 T651 aluminium, hardcoat anodised
- Screws Torx 20, zinc-nickel coated, pre-waxed
- Included Adjustable recoil screw, 10° wedge levelling key, manual
- Compatibility SAKO TRG-22, TRG-42, and Tikka T3x dovetail rifles
- Objective Clearance Designed for scopes with up to 56 mm objective lenses
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Direct dovetail fit for SAKO TRG-22, TRG-42 and Tikka T3x rifles, eliminating the need for additional rails.
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Integrated bubble level at the rear of the mount to ensure correct rifle alignment and prevent canting errors.
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Seven accessory interface points allowing attachment of over 40 different accessories from the Spuhr ISMS system.
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Diagonally cut rings that improve visibility of elevation and windage turrets without compromising strength.
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7075 T651 billet aluminium construction for maximum durability with reduced weight.
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Hardcoat anodised finish for long-lasting surface protection.
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Zinc-nickel coated Torx 20 screws that resist corrosion in all weather conditions.
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Pre-waxed screws from the factory for consistent and secure torque application.
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Adjustable recoil screw included for enhanced stability under heavy recoil.
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10-degree wedge levelling key supplied for quick and precise scope alignment.
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Designed for long-range performance, offering improved scope positioning and stability.
- Spuhr Aluminium One-Piece 36mm Dovetail Rifle Scope Mount - 14MOA
Why is a one-piece dovetail mount mechanically superior to split rings on a dovetail rail?
Split rings rely on the rail to align them; the ST-6401 does not. Because both rings are machined in the same fixture, their bores are perfectly coaxial. This prevents the scope tube from being forced into a bend when torqued down — a common cause of tracking errors.
How does the ST-6401 prevent scope tube ovalisation?
Spuhr machines the ring bores after anodizing so the internal diameter is exact. This ensures uniform radial pressure instead of point-loading, which can distort thin-wall 36 mm tubes and damage erector assemblies.
What role does the 14 MOA cant play in optical performance, not just ballistic reach?
By shifting the scope’s mechanical zero downward, the erector assembly operates closer to its optical center. This improves tracking linearity, minimizes optical distortion, and keeps parallax behavior more predictable at distance.
Does the ST-6401 reduce the need for shimming or bedding on dovetail rifles?
Yes. The mount’s base geometry is cut square to the ring axis, so the optic is already aligned to the dovetail’s reference plane, eliminating the need for corrective shims used on less precise mounts.
How does dovetail engagement differ from Picatinny recoil lugs?
Instead of a single recoil stop, the dovetail interface distributes recoil forces across the full length of the angled rail faces. This reduces micro-movement under recoil and prevents peening of a single lug.
Is the ST-6401 more tolerant of rail wear than separate rings?
Yes. Because it clamps across a long dovetail surface rather than two isolated points, wear on the rail is spread out, preserving alignment even after thousands of rounds.
How does this mount affect barrel harmonics?
The one-piece body resists torsional flex, so the scope mass does not oscillate independently of the action. This reduces tiny shifts in point-of-impact caused by optic mass reacting to barrel whip.
Can this mount support clip-on night-vision or thermal units?
Yes. The rigid, monolithic body keeps the scope’s optical axis stable relative to the bore, which is critical when using inline devices that depend on precise optical alignment.
Does the 14 MOA cant change how zeroing is performed?
Yes. Zeroing will occur with the elevation turret dialed slightly downward relative to mechanical center, which gives you more upward travel for long-range dialing while maintaining optical symmetry.
Why is this mount preferred on high-magnification 36 mm scopes?
Large-tube scopes have heavy erector assemblies. The ST-6401’s ring spacing and rigidity prevent tube flex that would otherwise degrade tracking and cause zero drift during recoil.
How does the ST-6401 handle temperature-induced zero shift?
The mount’s aluminum alloy is stress-relieved and anodized, reducing internal stresses that cause warping when temperatures swing from cold to hot firing conditions.
Why is ring spacing important on this model?
The ST-6401 spreads the rings far enough apart to stabilize long scope bodies, reducing bending moments on the tube when firing heavy recoiling cartridges.
Delivery costs & estimated arrival
Find your country below for the delivery charge and how long your order should take to reach you. All orders ship with FedEx. Estimates are in working days and exclude weekends and public holidays.
| Country | Up to 2kg | 2kg – 30kg | Estimated delivery | ||
|---|---|---|---|---|---|
| Order under €350 | Order €350 & over | Order under €350 | Order €350 & over | ||
| Austria | €11.95 | €26.95 | €26.95 | €26.95 | 5-7 working days |
| Belgium | €8.95 | €14.95 | €14.95 | €14.95 | 4-6 working days |
| Bulgaria | €11.95 | €31.95 | €31.95 | €31.95 | 7-9 working days |
| Croatia | €11.95 | €31.95 | €31.95 | €31.95 | 6-8 working days |
| Cyprus | €14.95 | €89.95 | €89.95 | €89.95 | Contact us |
| Czechia | €10.95 | €21.95 | €21.95 | €21.95 | 5-7 working days |
| Denmark | €10.95 | €21.95 | €21.95 | €21.95 | 4-6 working days |
| Estonia | €11.95 | €31.95 | €31.95 | €31.95 | 6-8 working days |
| Finland | €11.95 | €26.95 | €26.95 | €26.95 | 5-7 working days |
| France | €10.95 | €21.95 | €21.95 | €21.95 | 4-6 working days |
| Germany | €8.95 | €14.95 | €14.95 | €14.95 | 5-7 working days |
| Greece | €11.95 | €31.95 | €31.95 | €31.95 | 8-10 working days |
| Hungary | €11.95 | €31.95 | €31.95 | €31.95 | 5-7 working days |
| Ireland | €6.95 | €6.95 | €8.95 | €8.95 | 2-4 working days |
| Italy | €10.95 | €21.95 | €21.95 | €21.95 | 5-7 working days |
| Latvia | €11.95 | €31.95 | €31.95 | €31.95 | 6-8 working days |
| Lithuania | €11.95 | €31.95 | €31.95 | €31.95 | 6-8 working days |
| Luxembourg | €11.95 | €31.95 | €31.95 | €31.95 | 5-7 working days |
| Malta | €14.95 | €89.95 | €89.95 | €89.95 | Contact us |
| Monaco | €10.95 | €21.95 | €21.95 | €21.95 | 4-6 working days |
| Poland | €10.95 | €21.95 | €21.95 | €21.95 | 5-7 working days |
| Romania | €11.95 | €31.95 | €31.95 | €31.95 | 6-8 working days |
| Slovakia | €11.95 | €31.95 | €31.95 | €31.95 | 5-7 working days |
| Slovenia | €11.95 | €31.95 | €31.95 | €31.95 | 6-8 working days |
| Spain | €11.95 | €26.95 | €26.95 | €26.95 | 5-7 working days |
| Sweden | €11.95 | €26.95 | €26.95 | €26.95 | 5-7 working days |
Returns & withdrawal
Which option you use depends on why you are sending the item back.
Changed your mind?
You have 14 days from receiving your order to withdraw from your purchase. Use our Withdrawal from Contract form to tell us. It is the quickest way, and we will then email you a free returns label.
If you would rather post the item back yourself to our returns address in Ireland, you pay the postage. Full details are on our Returns page.
Withdrawal from ContractFaulty, damaged or wrong item?
If your item arrived faulty, damaged or not what you ordered, please follow the steps on our Returns page. We cover the cost of returning these items.
Full details of all our return options are on that page.
Returns pageDelivery prices are shown in euros and confirmed at checkout.
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