Spuhr ISMS SP-4801C Ø34mm Tube 13 MIL (30mm High) Gen 3 Picatinny Scope Mount
"The SPUHR ISMS Gen 3 SP-4801C is a precision-engineered one-piece mount that combines solid construction with practical versatility. Its medium height and 13 MIL incline make it ideal for long-range shooters seeking consistent elevation adjustments without compromising stability. The 34mm body perfectly balances optic clearance and weight, ensuring reliable zero retention even under the harshest conditions. For tactical, competition, or general precision use, this mount is a dependable choice that won’t let you down." - Thomas.
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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
- Rings: 34 mm
- Tilt: 13 MIL/44.4MOA
- Height: 30 mm/1.18”
- Length: 120 mm/4.72” (body), 130 mm/5.12” (OAL)
- Weight: 217 g/7.7 oz
- Interfaces: 7 sets
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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.
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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.
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Hard‑anodised surface treatment - Type III hard anodising delivers excellent abrasion resistance, corrosion protection, and a non‑reflective tactical finish.
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Diagonal ring split design - Improves load distribution around the scope tube while keeping elevation and windage turrets fully accessible, preventing obstruction during adjustment.
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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.
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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.
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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.
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Precision‑cut recoil lugs and rail interface - Provides repeatable, slip‑free engagement with Picatinny rails for consistent return‑to‑zero performance.
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High‑strength fastener system - Torque‑optimised fasteners maintain clamping force under vibration and recoil, preventing optic movement or zero shift.
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Designed for extreme‑range precision - Engineered to support the mechanical and optical demands of ELR, PRS, and professional long‑range shooting platforms.
- Spuhr ISMS Gen 3 SP-4801C 34mm Medium (30mm) 44.4 MOA Picatinny One-Piece Mount
- Manual
- "Wedge" levelling key
How does extreme cant affect erector system centering for ultra‑long‑range shooting?
Large cant angles shift the mechanical zero significantly downward within the scope’s adjustment range, allowing maximum upward elevation travel. This keeps the erector assembly operating near its central position where spring forces remain balanced and tracking behavior is more predictable.
Can extreme cant improve tracking repeatability at long distances?
When the erector system operates closer to its mechanical center, adjustment forces remain more uniform across elevation changes. This reduces the likelihood of hysteresis or slight return-to-zero deviations after large adjustments.
Does extreme cant influence optical clarity at high elevation settings?
Scopes adjusted near their internal limits may use lens regions farther from the optical center. Using cant reduces required adjustment and keeps the optical path closer to its optimal alignment.
Can improper torque affect cant alignment accuracy?
Uneven rail screw torque can introduce slight angular deviation in the mount body. This alters the effective cant angle and changes the elevation relationship between optic and bore.
How does extreme cant affect zeroing procedures?
Zeroing typically occurs near the lower portion of the elevation adjustment range. This requires careful adjustment to avoid reaching the lower mechanical stop prematurely.
How does ring alignment affect precision at extreme ranges?
Small alignment errors produce larger angular deviations at long distances. Precise ring alignment ensures the optical axis remains parallel with the mount structure.
How does cant influence internal scope spring pressure?
Large upward adjustments compress erector springs unevenly in flat mounts. Cant reduces required adjustment and maintains more balanced spring compression.
Does mount placement affect elevation travel usage?
Forward or rearward placement does not change total elevation travel available. It only affects eye relief and shooting ergonomics.
Can excessive ring torque affect scope tracking?
Excessive torque can slightly deform the scope tube and increase friction in the erector mechanism. Increased friction may produce inconsistent adjustment increments.
Does temperature variation affect cant accuracy?
Uniform thermal expansion preserves the geometric relationship between rings and base. The cant angle remains mechanically unchanged across temperature variations.
Can extreme cant limit close-range zeroing?
Large cant angles reduce downward adjustment travel available. Extremely close zero distances may approach the lower mechanical limit of the scope.
How does the mount maintain alignment during repeated adjustments?
The monolithic structure prevents ring movement relative to the base. This ensures that scope adjustments occur within a stable mechanical reference frame.
What installation error most often affects ultra-long-range performance?
Uneven rail screw torque is the most common cause of angular misalignment. This changes the effective cant angle and reduces usable elevation consistency.
Our aim is to ensure that your order arrives with you as soon as possible and in the safest, most cost-effective means.
Please Note: Shipping charges may be subject to additional surcharges if out of area or over weight restrictions.
Please Note: DPD SHIPMENTS REQUIRE THE CUSTOMER TO SHOW A PIN CODE ON DELIVERY - READ MORE: HERE
COURIERS
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We use DPD , RoyalMail, TNT and UPS courier services for all our orders whether dispatching to the UK or International. As soon as your order has been dispatched you will receive an email with your unique tracking number. We are unable to add delivery notes to your order regarding safe spaces or neighbour deliveries. If you require this service it can be arranged directly with the courier once the parcel is in their network.
IN-STORE ITEMS
These are items that we have in-stock and will be sent out for delivery as soon as possible. We aim to dispatch all orders within 1-2 working days, but during busy periods dispatch may be delayed by a day or so. If you would like to purchase the item in person then please call ahead to arrange an appointment: 01803 611 895.
PRE-ORDER ITEMS
These are usually items that are going to be out-of-stock for a number of weeks or are in short supply. By purchasing a Pre-Order Item you are in effect paying a deposit for your goods. As soon as the item is back in stock yours will be dispatched within 24 hours where possible. Please see individual product pages for current back-in-stock dates. In rare occasions, these dates can be changed by the manufacturers so we recommend staying in contact with Optics Warehouse depending on the product lead time.
INTERNATIONAL DELIVERY & TAXES
In addition to the above information If your delivery address is outside of the UK you may be subject to import duties and taxes, which are levied once a shipment reaches your country. Any such additional charges for customs clearance must be borne by you. You should note that customs policies vary widely from country to country. Optics Warehouse advises each customer to contact their local customs office for further information if they are in any way unsure of local duties or liabilities. Cross border shipments are subject to opening and inspection by customs authorities which means some packages may be opened and re-sealed.
NEED HELP?
If you require any further assistance, please call us on 01803 611 895 or email sales@opticswarehouse.co.uk
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A NOTE ABOUT DPD SHIPMENTS:
- Please be advised that we have now introduced DPD Pins to all DPD orders from Optics Warehouse.
- If your shipment is being sent from Optics Warehouse via DPD you will be sent a Pin Code that must be shown to the courier upon delivery.
- The pincode is sent VIA email & TEXT message. A valid email address and mobile number must be provided at checkout. Emails will be sent from "Riviera House 3PL" - if you do not receive this email please check your junk or spam folders.
- Please note that if you do not display your pin code to the courier driver upon delivery, you will not be able to have your item and you may need to schedule another delivery date to show a valid pin.
- Please view the attached slides HERE for further information!