The Primary Arms PLx 30mm Cantilever Scope Mount, 1.5 in height, black (part number 910084, SKU PA-PLX-CM-30-1.5) is a one-piece cantilever mount that fixes a 30 mm tube rifle scope to an M1913 Picatinny rail at a 1.5 in (38 mm) optical centreline. It is machined from 7075 aluminium with grade 12.9 steel hardware, uses a three-bolt ring design with dual recoil lugs and three cross-bolt lugs, and generates over 6,500 lb (2,950 kg) of clamping force.
A cantilever mount exists to solve one problem: on an AR-pattern rifle the receiver rail ends before the scope's eye relief wants it to, so the rings have to reach forward. This one does that in a single rigid piece, which is what keeps zero through recoil and lets you take the scope off and put it back without hunting for the zero again. The 1.5 in height is the conventional choice, giving a normal cheek weld with iron-sight-height comb positions.
How It Compares
This is the standard-height PLx mount. For a heads-up shooting position or a night-vision-friendly build, the PLx 30 mm cantilever mount at 2.04 in height in clear anodised sits the optic higher. For the same 1.5 in height at a lower price, the Primary Arms SLx 30 mm cantilever mount is the value option, and for 34 mm tube scopes such as the SLx 1-10x28, use the Primary Arms SLx 34 mm cantilever mount. This mount fits the 30 mm tube of the PLxC 1-8x24 FFP with the ACSS Griffin MIL G2 reticle and the SLx 1-6x24 Gen IV with the ACSS Nova reticle. Browse all rifle scope mounts and read our scope mounts and rings buyer's guide.
Ideal For
- Straight-pull AR-platform rifles in Great Britain needing forward eye relief from a receiver rail
- Civilian Service Rifle and practical rifle builds wanting a conventional cheek weld
- Shooters who remove and refit an optic and need it to return to zero
- Any 30 mm tube LPVO on an M1913 Picatinny rail
Key Features
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Ring size: 30 mm, for scopes with a 30 mm main tube
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Height: 1.5 in (38 mm) optical centreline, the conventional height for a normal cheek weld
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Construction: One-piece 7075 aluminium body with grade 12.9 steel hardware
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Retention: Three-bolt ring design, dual recoil lugs and three cross-bolt lugs
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Clamping force: Over 6,500 lb (2,950 kg)
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Rail: M1913 Picatinny
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Torque: Ring screws 16–18 in-lb (1.8–2.0 Nm), base screws 30–35 in-lb (3.4–4.0 Nm)
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Finish: Black anodised
Technical Specifications
| Product Type |
One-piece cantilever rifle scope mount |
| Ring Diameter |
30 mm |
| Height |
1.5 in (38 mm) optical centreline |
| Rail |
M1913 Picatinny |
| Material |
7075 aluminium body, grade 12.9 steel hardware |
| Retention |
Three-bolt rings, dual recoil lugs, three cross-bolt lugs |
| Clamping Force |
Over 6,500 lb (2,950 kg) |
| Ring Torque |
16–18 in-lb (1.8–2.0 Nm) |
| Base Torque |
30–35 in-lb (3.4–4.0 Nm) |
| Finish |
Black anodised |
| SKU / MPN / UPC |
PA-PLX-CM-30-1.5 / 910084 / 818500015543 |
What's Included
- Primary Arms PLx 30 mm cantilever scope mount, 1.5 in height
UK Delivery & Support
This mount is UK-stocked and dispatched tracked from our UK warehouse — no import duties and no customs delays — backed by UK-based aftersales support.
Frequently Asked Questions
What size scope tube does the Primary Arms PLx cantilever mount fit?
This mount has 30 mm rings, so it fits rifle scopes with a 30 mm main tube. Scopes with a 34 mm tube need the 34 mm version instead.
What rail does the Primary Arms PLx cantilever mount attach to?
The Primary Arms PLx cantilever mount attaches to an M1913 Picatinny rail, using three cross-bolt lugs and dual recoil lugs to resist movement under recoil.
What does 1.5 in height mean on a scope mount?
The 1.5 in figure is the optical centreline height, measured from the top of the Picatinny rail to the centre of the scope tube, which is the conventional height and gives a normal cheek weld on most AR-pattern rifles.
What torque should I use when fitting this mount?
Primary Arms specifies 16 to 18 inch-pounds, which is 1.8 to 2.0 newton metres, for the ring screws, and 30 to 35 inch-pounds, which is 3.4 to 4.0 newton metres, for the base screws.
Why choose a cantilever mount rather than separate rings?
A cantilever mount extends the rings forward of the rail section it clamps to, which is necessary on AR-pattern rifles to set correct eye relief, and its one-piece body keeps the two rings in perfect alignment so the scope tube is not stressed.
Should I choose the 1.5 in or the 2.04 in height?
Choose 1.5 in for a conventional cheek weld and a lower sight line, and choose 2.04 in for a more upright heads-up shooting position or where a night-vision device needs to sit in line with the optic.
