Questions, answered.

All orders are paid through PayPal at checkout. You are taken to PayPal to approve the payment, so your card or bank details are handled by PayPal and never shared with us.

Yes. Bundle & Save is applied automatically at checkout, with no code needed:

• 2 items: 5% off the order
• 3 items: 10% off the order
• 4 or more items: 15% off the order

The quantity counts every item in your bag, so you can mix products, for example a stock, grip and sling. You will see the discount in the order summary before you pay.

Email support@onyxarmaments.co.uk straight away with your order number and the change you need. We can help most easily before the order is dispatched. After dispatch, your 30-day right to cancel still applies (see Returns).

Yes. We sell branded products from the manufacturers named on each listing, such as Magpul, Geissele, Holosun, EOTech, Streamlight and SureFire. We do not sell replicas, clones or unbranded copies. If a listing ever looks wrong to you, tell us and we will check it.

Yes. You must be 18 or over to place an order. By ordering, you also confirm that you are legally allowed to buy, own and use the items for a lawful purpose (see Legal & buying in the UK).

We deliver anywhere in the United Kingdom. We do not currently ship outside the UK.

Delivery is a flat £5 per order, however many items you buy, sent by Royal Mail Tracked 24.

Please allow 7 to 10 business days from the day you order (Monday to Friday, not counting UK bank holidays). We order products in from the manufacturer rather than holding them in UK stock, and that is why delivery takes longer than a next-day parcel. The delivery estimate on each product page shows the actual dates.

We email you a tracking number as soon as your order is dispatched. You can follow it on our Track your order page or on the Royal Mail website.

Usually not, because standard orders go by Royal Mail Tracked 24. Higher-value orders may be sent on a signed-for, insured service at no extra cost, to protect your order in transit.

Email support@onyxarmaments.co.uk within 48 hours of delivery with photos of the outer packaging and the product. Please keep all the packaging until we have sorted it out. Damaged goods are covered by your statutory rights, and we will pay for the return.

No. We sell online only and do not have a shop or trade counter, so we cannot offer collection or visits.

You can cancel within 30 days of receiving your order, without giving a reason. You then have 14 days to send the item back. Items must be unused and returned in their original packaging. The full terms are in our Refund policy, and none of this affects your statutory rights.

Email support@onyxarmaments.co.uk with your order number and the item or items you want to return, and we will send you return instructions. Please do not send anything back before you receive these, because a parcel without a reference is hard to match to an order.

If you change your mind, you pay the return postage. We recommend a tracked, insured service, because we cannot be responsible for a return that is lost in transit. If an item is faulty, damaged or not what you ordered, we pay reasonable return costs.

We refund to your original payment method within 14 days of receiving the goods back, or of receiving proof that you have sent them. PayPal or your bank may need a few more days to show the refund.

Yes, if it is within the 30-day cancellation period and the part is unused and in its original packaging. You can trial-fit a part to check fitment, but please be careful:

• Don't cut, file or modify anything.
• Don't apply thread locker or grease.
• Don't fully torque mounts or ring caps.
• Don't fire the rifle with the part fitted.

If a part comes back marked or used, we may reduce the refund to reflect the loss in value. If you are unsure before ordering, email us first. We would rather check fitment for you than process a return.

Under the Consumer Rights Act 2015, goods must be as described, of satisfactory quality and fit for purpose. If something is faulty, email us with your order number, a description of the fault and, if possible, a photo or short video. We will arrange a repair, replacement or refund as appropriate. Many manufacturers also offer their own warranty, which is in addition to your statutory rights.

The right to cancel does not apply to gift cards or to goods made to order or personalised to your specification. This does not affect your rights if an item is faulty.

Every product page has a Compatibility & Fitment section based on the manufacturer's information. It covers the platform, the mounting interface and any restrictions. If you are still unsure, email support@onyxarmaments.co.uk with the make, model and generation of your rifle, and a photo if you can. We check against the manufacturer's data rather than guessing, and we will tell you plainly if something is unconfirmed.

Often, but not always. Most UK straight-pull rifles built on the AR pattern use standard AR-15 lower receiver interfaces. That usually means they accept standard pistol grips, receiver-extension stocks and many drop-in triggers. Some makers use their own upper receivers, cocking or bolt-release systems, handguards or trigger groups, and these may not accept standard parts. Before ordering, check your rifle maker's specification or email us with the exact model.

Some do. Many .308-sized lowers take the same pistol grips and receiver-extension stocks as an AR-15, and many take the same fire-control parts. Handguards, barrel nuts, charging handles and other upper-receiver parts are specific to the larger receiver, and they don't swap across. AR-10s are also not fully standardised. The two main patterns (DPMS/LR-308 and Armalite) differ from each other, so check the listing or our AR-10 & LR-308 parts collection.

M-LOK is a slot system: accessories bolt directly into rectangular slots in the handguard, which keeps the handguard slim and light. KeyMod is an older keyhole-shaped slot system, now largely replaced by M-LOK, and the two are not interchangeable. Picatinny (MIL-STD-1913) is a raised rail with cross-slots that accessories clamp onto. If you want to fit a Picatinny accessory to an M-LOK handguard, bolt a short Picatinny rail section into the M-LOK slots. Browse M-LOK accessories.

Not quite. Picatinny slots are 0.206in wide on consistent 0.394in centres. Weaver slots are narrower (about 0.180in) and are not always evenly spaced. Most Weaver-pattern mounts will fit a Picatinny rail. A Picatinny mount with a full-size recoil lug often won't seat in Weaver slots.

The outside diameter of the receiver extension (buffer tube) is different:

• Mil-spec: about 1.148in, usually with a flat, squared-off rear.
• Commercial: about 1.168in, often with a sloped rear.

A mil-spec stock won't slide onto a commercial tube, and a commercial stock on a mil-spec tube will wobble. Measure your tube across the threads-free section with callipers. Every stock listing tells you which tube it needs.

Most adjustable (collapsible) AR stocks fit a carbine-length tube. Traditional fixed rifle stocks, such as A2-style stocks, need a rifle-length tube with the matching rifle buffer and spring. Some fixed stocks, such as the Magpul MOE Fixed Carbine, are designed for the carbine tube. If you change tube length, the buffer and spring must change with it, or the rifle will not cycle correctly.

Yes. On an AR-15 the grip holds the safety selector detent spring in place. When you remove the grip screw, the detent and spring can drop out and are easily lost, so work over a tray. When you fit the new grip, make sure the spring sits in its channel before you tighten the screw. The selector should click positively between SAFE and FIRE.

A single-stage trigger has one consistent pull, then breaks. It is quick and simple, and suits fast, close-range shooting. A two-stage trigger has a light first stage of take-up, then a distinct wall, then a short, crisp second stage. The wall makes a precise, deliberate shot easier, so two-stage triggers are popular for precision and target shooting. Compare our single-stage and two-stage triggers.

The trigger and hammer pins pass through holes in the lower receiver. Standard AR-15s use small pins (0.154in). Some older Colt lowers and some .308-sized lowers use large pins (0.170in). A trigger must match your receiver's pin size, although some manufacturers supply adapter pins. Measure the pin holes or check with your rifle's maker before you order.

A drop-in trigger comes as a single self-contained unit, pre-assembled and pre-adjusted at the factory, so there is no need to fit the individual springs, disconnector and hammer. That makes installation simpler and less error-prone. A component (mil-spec style) trigger is fitted part by part. Either way, always do a function check afterwards.

It can if the hammer spring is reduced too far. Some lighter pull weights are achieved with reduced-power hammer springs, and these can cause light primer strikes with hard military-style primers. Use the springs the trigger maker specifies for your ammunition. Don't cut or modify springs to chase a lighter pull.

If you are confident and have the right tools, yes, but follow the manufacturer's instructions exactly. If you have any doubt, have a competent gunsmith fit it. After fitting, always do a function check with the rifle unloaded:

• With the selector on SAFE, the trigger must not release the hammer.
• On FIRE, the hammer must fall.
• Hold the trigger back, cycle the action, then release the trigger slowly. It must reset with an audible click, and the hammer must stay cocked.

If any step fails, don't use the rifle until it has been checked.

Yes. We sell Remington 700 triggers, which also fit many actions built to the Remington 700 footprint, and rimfire & bolt-action triggers for other popular models. Remington 700-pattern actions differ in their safety and bolt-release arrangements, so check the listing's compatibility notes for your exact action.

Red dot sights project an LED dot onto a coated lens. They are light, compact and often have very long battery life. Holographic sights, such as EOTech, use a laser to reconstruct the reticle in a larger window. The reticle can look crisper, but the battery life is shorter. Prism scopes use an etched glass reticle with fixed magnification (often 1x to 5x), so the reticle is still visible without a battery. Prism scopes also suit many shooters with astigmatism. Browse red dots, holographic sights and prism scopes.

Usually not. This is most often astigmatism in the eye. To test, look at the dot and rotate the sight. If the smear rotates with the sight, the sight may be at fault. If the smear stays the same, it is your eye. Turning the brightness down often helps. Many shooters with astigmatism also see a prism scope's etched reticle, or a holographic reticle, more clearly.

MOA (minute of angle) is an angular measurement. 1 MOA is about 1.047in at 100 yards, or about 2.9 cm at 100 m. A 2 MOA dot therefore covers about 5.8 cm at 100 m, and a 6 MOA dot about 17.5 cm. Smaller dots cover less of the target, which suits precision shooting. Larger dots are quicker to pick up at close range.

The human eye is most sensitive to green light. A green dot therefore looks brighter at the same setting, and many people find it crisper. Red is the traditional choice. A gold dot stands out against both green and brown backgrounds. It comes down to personal preference, and it is worth trying each if you can.

A footprint is the screw and recoil-boss pattern on the base of a mini red dot. It decides which mount or adapter plate the sight fits. The common footprints are:

• RMR
• RMSc
• Leupold DeltaPoint Pro
• Aimpoint ACRO (enclosed)
• Aimpoint Micro/T-1 (used by many rifle red dots)

A sight fits a mount only if the footprints match, or if you use the correct adapter plate. Each sight listing states its footprint.

Co-witness means the red dot and your iron sights line up. On a flat-top AR-15:

• Absolute co-witness: the dot sits on the front sight post. The optical centre is about 1.41in above the rail.
• Lower-third co-witness: the irons sit in the bottom third of the window. The optical centre is about 1.5 to 1.6in above the rail.

Taller mounts give a more upright head position, which many shooters prefer with a plate carrier or helmet. See scope mounts & risers.

In a first focal plane (FFP) scope, the reticle grows and shrinks with magnification. Its holdover and ranging marks are correct at every magnification. In a second focal plane (SFP) scope, the reticle stays the same size, so it is easy to see at low power. Its marks are only correct at one magnification, usually the highest. FFP suits precision shooting at distance. SFP is common on hunting scopes and many LPVOs.

Rings must match the scope's tube diameter: usually 1in, 30mm, 34mm or 35mm. The ring height must give enough clearance for the objective bell and let you look through the scope with your head in a natural, relaxed position. For AR-pattern rifles, a one-piece cantilever mount places the scope far enough forward for correct eye relief. See precision scope mounts.

Use a torque driver and the manufacturer's specified values, which are printed in the instructions for each mount. Ring-cap screws are specified much lower than the clamp that holds the mount to the rail. Over-tightening can crush a scope tube or strip threads. Tighten ring caps evenly in a cross pattern, so the gaps on each side are equal.

First, get on paper at a short distance: 25 m is common. Then confirm your zero at your chosen distance. For an AR-15 with a red dot, a 50 m zero is popular. For magnified scopes, 100 m is typical. Fire groups of three to five shots and adjust from the centre of each group, not from single shots. Your optic's manual gives the value of each click, for example 0.5 MOA or 0.1 mil. 1 mil is 10 cm at 100 m.

Lumens measure the total light output, which determines how much the light fills a room. Candela measures beam intensity, which determines how far the light reaches and how well it punches through. The ANSI FL1 beam distance is roughly 2 × √candela in metres, so 20,000 cd gives a beam distance of about 280 m. For use outdoors at distance, prioritise candela. Indoors, very high lumens can reflect back off pale walls. Compare weapon lights.

Only if the manufacturer approves them for that model. Rechargeable RCR123A cells often run at a higher voltage than primary CR123A cells. In a light not rated for them, they can shorten its life or damage it. Some lights, such as our rechargeable weapon lights, are designed for a specific rechargeable battery pack. The listing and the manual give the approved batteries.

Mount the light as far forward as practical, and close to the bore line, so the barrel casts as little shadow as possible. Make sure you can reach the switch without shifting your grip. Many shooters use a remote pressure switch on an M-LOK handguard. See weapon light accessories for mounts and switches.

Yes:

• Treat the laser like a firearm, and never point it at anyone.
• Shining a laser at a vehicle, vessel or aircraft is a criminal offence in the UK.
• Infrared (IR) lasers are invisible to the naked eye but can still cause eye injury. They are intended for use with night-vision equipment.

Each listing states the laser's colour and type.

No. The items we sell are accessories and non-controlled parts: optics, mounts, lights, stocks, grips, triggers, handguards, slings and bipods. None of them is a controlled component part of a firearm. Under the Firearms Act 1968, the relevant component parts that need certificate authority are:

• the barrel, chamber or cylinder
• the frame, body or receiver
• the breech block, bolt or other mechanism for containing the charge at the rear of the chamber
• the slide

We do not sell any of these. You are still responsible for making sure your purchase and its use are lawful where you live.

Yes. Firearms law in Northern Ireland is separate from the law in Great Britain (the Firearms (Northern Ireland) Order 2004). We deliver across the UK, but it is your responsibility to check that an item is lawful for you to own and use where you live.

In general, yes. Fitting accessories such as optics, stocks, grips and lights to a rifle you lawfully hold is normal owner maintenance. If a job involves the barrel, receiver or bolt, or if you are unsure whether a change is permitted, speak to a registered firearms dealer or your police firearms licensing department before you start.

No. The answers on this page are general information to help you choose parts. They are not legal advice. For questions about your own certificate or circumstances, contact your police firearms licensing department or a solicitor.

By email, at support@onyxarmaments.co.uk. We aim to reply within one working day (Monday to Friday, not counting UK bank holidays). Please include your order number if you have one, and your rifle's make and model for fitment questions. You can also use our contact form.

We handle all customer service by email. That way every answer is in writing, and fitment advice can include the exact part numbers and links.