Spuhr ISMS QDP-4616 Ø34mm Tube 6 MIL (34 mm High) Cantilever Quick Detach Picatinny Scope Mount

Picatinny mount for use on AR10 rifles

• Ring Diameter: 34 mm
• Tilt: 6 MIL/20.6 MOA
• Height: 38 mm/1.5”
• Length: 151 mm/5.94” (mount body only)
• Weight: 270 g/9.5 oz
• Interfaces: 8 sets
• EAN: 7340150705084

• Monolithic one‑piece construction - CNC‑machined from a single billet of aerospace‑grade aluminium to eliminate tolerance stacking, flex, and ring misalignment common in multi‑piece mounts.

• High‑rigidity structural geometry - Optimised cross‑section and material distribution provide exceptional torsional and vertical stiffness, maintaining optic alignment under heavy recoil and dynamic loading.

• Hard‑anodised surface treatment - Type III hard anodising delivers excellent abrasion resistance, corrosion protection, and a non‑reflective tactical finish.

• Diagonal ring split design - Improves load distribution around the scope tube while keeping elevation and windage turrets fully accessible, preventing obstruction during adjustment.

• Integrated scope levelling system - Built‑in bubble level allows the shooter to reference rifle cant and optic alignment directly on the mount for precise long‑range shooting.

• Multi‑axis accessory interface -  Machined mounting points on multiple faces of the mount support direct attachment of optical and electronic accessories without adding separate rails.

• Low‑profile accessory mounting - Keeps mounted devices close to the bore axis and centre of mass, preserving rifle balance and minimising parallax and offset errors.

• Precision‑cut recoil lugs and rail interface - Provides repeatable, slip‑free engagement with Picatinny rails for consistent return‑to‑zero performance.

• High‑strength fastener system - Torque‑optimised fasteners maintain clamping force under vibration and recoil, preventing optic movement or zero shift.

• Designed for extreme‑range precision - Engineered to support the mechanical and optical demands of ELR, PRS, and professional long‑range shooting platforms.

How does the 1.57″ forward offset affect scope alignment relative to the bore?
The forward offset increases eye relief while keeping the optical axis properly aligned with the bore, allowing for larger objective lenses or clip-on devices without introducing parallax issues.

What advantage does the built-in 20 MOA cant provide?
It shifts the scope’s internal elevation downward, keeping the erector assembly near its mechanical center for extreme long-range shots, which improves linear tracking and reduces potential distortion at high elevation values.

How does cantilevering impact cheek weld and ergonomics?
By extending the scope forward, the shooter can maintain a natural cheek weld even with high comb stocks or long barrels, minimizing neck strain and improving consistent head positioning.

How critical is proper torque when installing this cantilevered offset mount?
Very critical. Because the optic mass is shifted forward, asymmetric or incorrect torque can induce tube stress or subtle alignment shifts, affecting tracking and repeatability.

Does the mount maintain co-witness with backup iron sights?
Yes. The forward offset is engineered to clear irons while maintaining mechanical alignment, allowing absolute or lower co-witness depending on stock geometry.

How does the QDP locking system prevent zero shift under recoil?
The dual-cam system engages both the top and side surfaces of the rail slot, distributing recoil forces across a larger area and preventing creep or micro-shifts during repeated heavy recoil.

What effect does the forward optical position have on parallax performance?
It improves linearity in parallax adjustment across distance, as the longer eye-to-bore distance reduces extreme angular errors at high magnification.

Can the mount handle high-magnification optics with heavy objective lenses?
Yes. The wide ring spacing and rigid one-piece design resist torsional flex, preventing tube deformation that could compromise reticle integrity.

Is this mount compatible with suppressors and thermal or night vision devices?
Yes. The forward offset provides sufficient clearance for suppressors and clip-on devices while keeping the optic stable relative to the bore.

How does the mount influence reticle stability during follow-up shots?
By minimizing torsional flex and keeping the optical axis aligned, the mount reduces oscillation and drift in the reticle during rapid or repeated fire.

What role do the recoil lugs play on this model?
They lock the mount against both the longitudinal and lateral surfaces of the rail, spreading recoil forces evenly and preventing rearward creep.

Does forward offset affect elevation and windage adjustments?
No. While elevation is aided by the cant, the optical axis remains properly aligned, keeping windage tracking consistent.

How does this mount perform on magnum-caliber rifles?
The reinforced base, one-piece construction, and dual cam interface allow it to handle sharp, high-energy recoil without losing zero.

Why would a long-range shooter choose this mount over a standard QDP?
It combines forward eye relief, a 20 MOA cant for extreme elevation, and stable QDP repeatability, making it ideal for precision long-range applications where scope clearance and adjustment range are critical.