SHS M4 Series Replacement Metal Hop Unit

When buying your first Airsoft gun, do not forget to purchase yourself some eye protection, because without it you are at serious risk of damaging your eyes.

Remember these guns have a high velocity when leaving the barrel of your gun. It's also important to protect others around you when using your Airsoft gun, so make sure they have face protection as well. NEVER point an Airsoft gun at an individual without face protection.

NEVER take your face protection off for any reason on site, if there is a problem shout for a marshall and they will help you out. It’s also a bad idea to smile like a Cheshire cat as well no matter how much fun you’re having, a sniper may shoot out one of your teeth, unlikely but it does happen.

When transporting your Airsoft gun, remember that you are carrying an item that is made to look like a real gun. The public and the police may not take it so lightly if you carry your gun inappropriately.

Always transport your airsoft gun in a non-descriptive bag or case.

Make sure your gun is NOT loaded when in transport

The original box does not count as a suitable transportation device, due to the markings and often a picture of the gun being present. On this note, a supermarket plastic bag, hand bag, rucksack are also not considered as suitable. See our section on Gun Cases / Bags for more details.

Most Airsoft guns do NOT include a battery or a charger unless it is either specified in the description or there is an option to add a battery to the product. If it does not say, then you will need to add a battery and a charger to your order.

When selecting your charger you will need to match the battery type.

NiMH batteries can be charged with an NiMH battery charger

LiPo / LiFe batteries will requies a LiPo / LiFe battery charger

BB pellets are quite simply the ammo that your Airsoft gun will be using. Choosing the right BB's can be just as important as choosing the right gun in terms of weight. BB weight is simply how heavy the BB is, with 0.2g being the most common so use that to start with. ROF is rate of fire, or how many BB's you shoot a second. A high rate of fire sounds good, but the higher the ROF, the quicker you will use your ammo.

Don't worry about it too much. Since you will be shooting a lot of BB pellets, we also recommend you think about the environment and use biodegradable BB's.

These product are suggested for users 18 years or older.
● Wear face protection while shooting.
● Misuse may cause injury or death.
● Never point at humans and animals with the airsoft guns.
● Read the whole manual before using.
● Buyers and users should obey the laws and rules of the local authority.

When shooting the air guns for target practice or in a game situation, you and all participants must wear safety goggles or other eye protective gear. Also, pay attention to ricochets. It is very important to pay attention to third parties other than the participants.

Always attach the safety cap to the muzzle, remove the battery and store the air gun in a case or bag and at a place that is out of reach by children.

Never direct the muzzle towards a person, animals or in any direction that may cause harm or damage to the third party.

ooking into the muzzle is extremely dangerous regardless of BBs having been loaded or not. If you get hit in the eye by a BB pellet, you may in worst case, lose your eye sight.

Disassembling or modifying the gun may adversely affect the performance and make it dangerous.

Your just starting to get into airsoft and you ask yourself what kind of gun can I get?

For anyone who is not currently registered in the UK as a UKARA member and is over the age of 18, you will want to purchase an Airsoft Two-Tone BB Gun. The guns are UK legal and comply with the VCR Act of 2007. If you live outside of the UK, the VCR Act does not pertain to you and you can purchase either a RIF Airsoft BB Gun or an Airsoft Two-Tone BB Gun.

A RIF is a (replica immitation firearm) and can only be purchased by licensed members of the UK or to persons living outside of the UK. If your billing address is outside of the UK and your delivery address is inside the UK, you will still need to be a licensed member to purchase a gun.

To be a licensed member you must either carry a valid UKARA player registration number or be a registered and insured member of a re-enactment group.

What gas is best for my gun? - As a general rule of thumb, anything out of Japan we warranty for use with Abbey Ultra Gas maximum and anything else for use with Green Gas maximum.

Can gas guns use C02 instead of green gas? - No, but some guns do use a C02 adapter.

A Hop-Up or Spinup system puts an upwards spin on the BB as it goes down the barrel. This reduces the affects of gravity to increase the flight time and range of the BB.

Metal Hydride Batteries (known also as NiMH Batteries) The initial charge should be 4 hours but no longer, and subsequent charges should last no longer than 2-3 hours (mini batteries only).

Overcharging your battery will ruin your battery so that it won't hold a charge. Remember to never overcharge your battery! For a more accurate estimate, take the mAh listed on the battery, the mAh of the output listed on your charger and use the following formula:

Battery mAh --------------------------- x 1.4 = Hours to Charge Charger Ouput mAh

This charge time is from fully flat.

If in doubt, purchase a good quality charger like the Vapex VTE500P whcih rapid charges the battery and when fully charged, drops to a trickle charge. Lithium polymer and Lithium Ferrite Batteries (also known as LiPo / LiFe batteries) Do not use a standard NiMH charger with LiPo/LiFe batteries as this runs the risk of fire and/or injury! Only use a good quality LiPo/LiFe charger and ideally a balance charger, like the Vapex VTE600 which balance charges the cells before switching off the charge circuit to stop over-charging.

FPS is feet per second in velocity and is a measurement in distance traveled. In theory the higher the FPS, the further the BB pellet will travel. But you will also need to take into account BB pellet weight and if you are using a Hop Up unit.

Here in the UK sales of airsoft guns are restricted. But don't worry, its easy to understand. If you are over 18 you can buy yourself a two tone gun (the ones that have bright paint on them) Or if you want them realistically coloured, you need to play at a registered site for at least two months and play at least 3 games. Then the site will help you fill in the form for you. If your under 18 you cannot buy either of the above. You can get a parent to 'gift' you one, either two tone or if they are registered themselves a RIF. Check out www.UKARA.org.uk for more info, or talk to your site organiser.

ROF is rate of fire, or how many BB's you shoot a second. A high rate of fire sounds good, but the higher the ROF, the quicker you will use your ammo.

The question widely asked of us is "How do I increase the rate of fire?", even on guns that are already putting BBs out in a solid stream - go figure...

Well this can be done easily with the change to a higher voltage battery or with a more technical approach, which can range from a less powerful spring -which reduces your F.P.S.- to the more elaborate use of the prototype sector gear that gives two piston strokes per revolution.Throw into this mix a high speed motor and what is the result? "Aha" you say "mind boggling BB carnage"---Wrong

Thrown together speed increasing set ups have a wonderful tendency to be rather short lived affairs, just like in nature if it moves quickly chances are it doesn't live long. Properly researched and engineered Grin-factor Twelve gearboxes do exist and are a thing of beauty but they are just that; PROPERLY ENGINEERED. Sometimes you have to just be satisfied with what you have as a R.O.F. and realise that if you cant hit your target with 2/3 BB's, then emptying 300 rounds ten feet short of target (although fun!), just wastes your ammo.

We accpept Paypal, Credit / Debit Card, Bank Transfers UK, Bank Transfers International

You will be required to log in or register on the checkout in order to place orders.

Paypal

On the checkout you will be redirected to the Paypal.com website, where you will either need to enter you paypal login details or select use Credit / Debit card. From there you will be redirected back to our website on successful login and payment.

Credit / Debit Card

We accept most major credit cards, VISA, Mastercard, JCB, Maestro. During the checkout process you will enter your card details. A successful transaction will redirect you to the order confirmation page.

Bank Transfer

To use our bank transfer method, you will need to select Bank Transfer on the checkout and take note of the bank transfer details that you will need to use. Pressing the place order button will create an order that is valid for 15 days. If we have not received payment within 15 days, your order will be terminated. Customers who abuse this method of payment will be blocked.

For Euro or USD, please use the details on the checkout for those retrospective accounts.

If you have placed an order with a two-toning service applied, it will take 5 days (times may vary during busy periods).

We will not dispatch your entire order until your gun has been painted.

If you require items shipped separately from a custom painted two-tone airsoft weapon, please place a separate order for those items.

If you are ordering a Replica Imitation Firearm (Any gun that is not a two-tone) and you are living outside of the UK, you can order a RIF as long as your local laws pertaining to owning an airsoft gun allow it.

We will not be responsible if you order an airsoft gun to a country that has strict controls in place and the package is destroyed on arrival.

We are unable to ship pyrotechnics or gun gas outside of the United Kingdom and Northern Ireland.

All other items will be sent by courier UPS or DPD.

On some items when we have an estimated time of arrival, we do offer a pre-order service. If you order a pre-order item and an instock item on the same order, this order will not be dispatched until the pre-ordered item has arrived.

Our pre-order estimated dates are subject to change if the shipment to our warehouse is delayed.

Please check product pages and Facebook for pre-order updates.

When ordering from our website we will make you aware of any age restrictions on a product.

All pyrotechnics, gun gas, kinves and airsoft guns must be purchased by someone of 18 years of age or older.

Please see our section on the VCRA for guidance.

Orders are usually processed quickly on Airsoft World and so cancelling an order needs to be done within an hour or two of purchasing. In order to cancel, please refer to the order id number in the email you received.

PLEASE CALL US. on 0333 344 9555

99% of orders are shipped the same day your order is received, so contacting us by email will not enable us to read your message in time to cancel your order before it is dispatched.

During peak times, our email backlog can be as much as three days before we manage to read it.

If you would like us to upgrade or downgrade a gun from our website, please see our Upgrades section of our website.

Select the product you would like to add to your gun and add it to your basket along with the gun you are upgrading / downgrading.

If you have an questions regarding upgrading / downgrading your gun, please call us on 0333 344 9555 to discuss possibilities.

• Magazine is too cold (Liquid gas fails to evaporate and create enough pressure)
• Loose breech block
• Defective or deformed BB pellet
• Magazine is defective or damaged
• Incorrect adjustment of back-spin (hop-up) mechanism.

Possible Solutions

• Place in normal room temperature or heat the magazine in your hands or pocket for a few minutes. do not place near heater, naked flames or strong heat
• Re-tighten
• Use high quality BB pellets that have no visible mold-seam or miss-shape. Do NOT ever re-use a fired BB!
• Deformity of magazine top or magazine outlet feed. Replace worn parts with new ones
• Move hop-up adjustment up if the BB's drop or down if the BB's curve upwards.

"My gun has stopped firing." - Now while this sounds to some like a meaningful statement, in honesty it tells us little unfortunately.

However where AEGs are concerned the first thing to check is the fuse (and the mot common call type I get enquiries about). Now while this little piece of kit is simple in construction it’s not really that useful in an AEG. The whole idea is that the fuse is a piece of wire that, when a current is passed through it greater than the wire can handle, it burns out.

Simple. Well not really.

Most AEGs use an inline glass fuse so you can see the fuse wire inside. So it should be a case of simply opening the fuse holder and looking at the fuse wire to see if it has indeed burnt out. Wrong I’m afraid. While in theory the fuse wire will burn out in the centre, a number of fuses are failing at the end caps. Whether this is because they are cheaply made and the solder hasn’t taken or in fact it’s a press fit and the contact has been broken, the simply fact is a visual inspection just isn’t enough.

To check a glass inline fuse correctly, either use a multi-meter or more conveniently, remove the fuse and directly connect the two fuse holder clips, clip them together and now try your AEG. If it fires, replace the fuse and you’re all done! If not, then it’s something more and may require the tender touch of your local airsoft technician to diagnose and repair.

So you have a game on tomorrow and the fuse has gone but after testing the gun fires fine. Your nearest airsoft retailer is an hour away and it’s 7PM at night. What do you do? Well don’t despair as the fuses are actually car fuses of around 25-30AMP so simply pop into your local garage shop and pick up a replacement for continued skirmishing joy. These are slow blow fuses so they allow a little more current drain before they go to allow for the motor to draw the current it needs to get up to speed.

Possible Cause

• Magazine is too cold/amount of gas is inadequate
• Oil in piston section has been used up
• Loose breech block
• Cracked cylinder
• Defective or malfunction of trigger
• Magazine BB feed outlet is damaged
• Abnormality of magazine feed outlet
• Lubrication of slide runner track not adequate
• Piston o-ring is deformed or missing
• Slide stop catch is deformed

Possible Solutions

• Wait until the pistol is at normal room temperature. Ensure magazine is full. Add silicon oil on nozzle rubber
• Wipe with silicon oil. If problem persists, it may be due to deterioration of O-ring replace→with new parts
• Refit tightly
• Replace with new part(s)
• Check if the sear or spring is worn→if yes, replace with new parts
• Replace with new parts and clean barrel feed chamber (where the BB's enter from magazine)
• Wipe with oil. If problem still persists, immediately replace with new parts
• Wipe oil on slide/frame track. If problem persists, replace or send for repair
• If slide stops in the middle, there may be a piston o-ring blown into the cylinder. Remove and replace with new piston ring
• Replace with new part

Possible Cause

• Incorrect magazine installation
• Inadequate gas pressure inside magazine
• Deterioration of Piston O-ring

Possible Solutions

• Reinstall until magazine lock is fastened (until it clicks)
• Replenish gas. If temperature of magazine is too low, wait until it is restored to normal room temperature
• Add silicon oil. If problem persists, replace with new one. Problem may be due to cracks in cylinder, replace as required

Possible Causes

• Gas is empty/gas leak
• Excess amount of gas pressure
• Deformity of spring in piston
• Pellet stuck in rubber chamber
• Poorly fitting magazine
• Pellet obstruction inside magazine
• Malfunction of valve impact hammer

Possible Solutions

• Refill gas in magazine. If the mag is oiled correctly and it still fails to work, send for repair or replace mag
• High temperature increases the gas pressure as it evaporates more quickly. Mags left in direct sunshine or just hot weather can cause this. Carefully release pressure and refill with fresh gas
• Replace with new parts
• Deformed BB, dirty/damaged chamber or the hop-up mechanism is on to high
• Install properly and insert magazine fully until it clicks
• May be due to foreign matter, deformity of magazine output lips, poor BB pellets. Remove foreign matter/replace parts as required
• Replace defective parts (may also be due to faulty safety mechanism or worn/dirty parts in the impact system

Possible Causes

• Temperature of magazine to high
• Inadequate amount of gas in your can or the fill-valve/nozzle on can is damaged
• Magazine fill-valve is damaged

Possible Solutions

• Press magazine discharge valve (gently!), loosen discharge valve to reduce internal pressure. Wait for magazine to restore to normal temperature and refill with gas
• Replace with new gas can
• Replace with new parts

Possible Causes

• Safety mechanism is closed
• Trigger return spring is damaged

Possible Solutions

• Pull up safety lever, remove safety mechanism
• Replace as required

Possible Causes

• Opening of magazine is deformed
• Deformity of magazine output 'lips'

Possible Solutions

• Always replace with a new one. Poor quality BB pellets can cause this damage

Possible Causes

• Abnormality of BB pellet
• Abnormality in sectional parts of barrel
• Synchronisation failure between moving parts
• Holding and gripping gun incorrectly

Possible Solutions

• Avoid using poor quality or deformed BB pellets. Use high quality, seamless and perfectly round BB's
• Replace with new parts if there are scratches or deformities in internal parts of BB chamber/inner barrel
• Lubricate slide, frame-assembly, gun barrel and other movable parts with oil or clean with warm soapy water and re-lubricate
• Try to avoid wrist or hand shake, grip tightly when shooting. Grip gun with both hands where possible