Beginners guide: AEG Performance and maintenance

Beginner’s Guide: AEG Maintenance and Performance

You may have been told various untruths about Airsoft AEGs in the past, and these usually revolve around AEG maintenance and performance. 

Certain other retailers and manufacturers prime new Airsoft skirmishers with unrealistically high expectations of their Airsoft AEGs, which can often result in disappointment and dissatisfaction. Manufacturers often display unrealistic range expectations on their boxes; we have seen several claiming accuracy at 70m+ which is very unlikely within UK legal muzzle energy parameters. 

Many players are convinced their AEG can shoot 100 metres, expect an extremely flat trajectory (ew spelling) and grouping sizes that are just unattainable. Others may watch YouTube videos filmed in Asia or America, where the limits of muzzle velocity are often dictated by the skirmish site they attend, rather than the government. Then you have the flip side - the guy who paid £30 for the cheapest AEG going and finds it performs horribly. He then proceeds to make claims that airsoft guns all have lousy performance, which simply is not true.

At Patrol Base, we’re here to dispel the Airsoft fake news and enlighten our newer players on what performance to expect from an AEG within UK legal limits. We’ll also explain proper airsoft AEG maintenance so that players can achieve maximum performance, plus we’ll share a few handy tips such as ‘the poor man’s chrono’ test. 

Informing new players with truth rather than trying to entice them with lies is important to us because we believe it’s the best way to build a knowledgeable community.

What to expect from an AEG out of the box 

As a baseline, you should expect around 30-50m accurate range, with a harassing fire that’s slightly beyond that - so long as it’s an un-upgraded AEG with a properly adjusted HOP.

Accuracy-wise, being able to hit an A4 sized target at 20m from a standing, unsupported position 9/10 times is considered to be "combat accurate" in Airsoft terms. However, a tight-bore barrel (6.04mm and smaller inner diameter) should provide some slight improvements.

Your AEG should fire with around 10% of its velocity in variance shot-to-shot at maximum (i.e a 330fps AEG should have all its shots between 300fps and 360fps approximately). Anything beyond this may indicate poor quality BBs, HOP issues, or an internal air-seal issue. 

Your rate of fire will vary depending on the motor type, gearbox internals, and size of the battery (both voltage and amperage). However, a minimum of 10-15 RPS (rounds per second) is what to expect from using the Airsoft batteries we recommend on our website.

Poor Mans Chrono

If you suspect your AEG is not shooting the stated velocity but you don't own a chronograph, there is a trick Airsofters have been using for decades to roughly ascertain their muzzle energy and velocity. Known as the ‘poor man's chrono’ or the ‘coke can test’, this is a good way to check your AEG to ensure it's skirmish ready. You will need the following:

  • Eye Protection 

  • Your AEG with a full magazine 0.2g BBs (this only works with 0.2g) and charged battery 

  • An empty coke can with no dents (Sprite, Dr Pepper, Fanta, Lilt etc.)

Once you have this collection of items ready, and somewhere safe and private to carry out your test, we can begin. 

Step 1 

You will want to load your AEG and place the muzzle between 3 and 5cm from the can, holding the can in your hand but being careful not to put your fingers in the line of fire (ouch).

Step 2 

Once you have done so and have your eye protection on (the same goes for anyone watching) you can fire a single shot into the can around the centre of its length (near the logo).

If the BB penetrates one side and ends up inside the can, your AEG shoots approximately 290-310fps (end the test here).

If the BB penetrates both sizes, you are shooting above 310 fps. If so, you need to continue the test.

Step 3 

Switch the can so that you’re shooting through the bottom edge (not the centre). If your 0.2g BB goes through the bottom edge, your AEG shoots at above 350fps and may not be allowed on site.

Keep in mind, this test is not particularly accurate and is valuable only to gain a very rough idea of what muzzle velocity your AEG shoots. It is not definitive proof of your AEGs performance. The ideal solution is to purchase a chronograph, as coke cans may vary in thickness and you will only ever get a round-about result with this test. 

The test will also not work if you use heavier BBs than 0.2g. I generally use this to check that any AEGs I have stored for some time have not been left with the spring compressed and are still at a skirmishable velocity.

AEG Gun Maintenance

The amount of AEG maintenance needed to sustain your gun’s functionality is small. What’s more, the consequences of not carrying out maintenance after every extended firing session are considerably less than with gas blowback pistols and other gas-powered airsoft guns. This is one of the many things that make an AEGs is a perfect choice for beginners. Apart from carrying out a full stripdown and re-lube of the gearbox (this may be necessary after a year or two, depending on how regularly you use the AEG and how/where it is stored), you will only have to do the following after each skirmish:

  1. Fire a handful of shots in semi-auto before storing - This will ensure your gearbox completes a full cycle before it is stored, preventing damage to the internals and spring
  2. Fire the AEG with no magazine, held upside-down, at least twice before leaving the firing range/skirmish site  - This ensures you are safely storing your AEG, as BBs can remain in the hop unit after the magazine is removed.
  3. Never leave your battery connected to your AEG when stored. - This can cause corrosion to build on the battery and AEG connectors, rendering both useless until replaced
  4. Do not store AEGs anywhere where damp is present (cellars/garages are the main culprit here). - This can cause irreparable damage to the finish on the outside, and result in rust on the steel components of the AEG.

Inner barrel cleaning 

Regularly cleaning your AEG inner barrel is an essential part of AEG maintenance, as this ensures your gun remains accurate and your HOP is at peak effectiveness. You will need a cleaning rod (supplied with every AEG), a small piece of microfiber cloth, and silicone lubricant (spray works best for this but any liquid silicone lubricant will work).

  1. You will first want to cut the micro-fibre cloth into a small strip, to fit inside the slot on the cleaning rod tip. 

  2. Proceed to wrap the cloth around the tip of the rod, until it barely fits inside the barrel. Ensure the AEG is unloaded and does not have a battery connected.

  3. Next, spray a small (very, very small!) amount of silicone lube down the barrel from the muzzle end. Then run the cleaning rod down the barrel from the muzzle end, repeating this and changing the cloth until the cloth comes out clean. 

  4. Be very careful to avoid pushing the cleaning rod into the hop unit (you should feel resistance at the end of the barrel) as this can damage the hop-up. 

  5. Following barrel cleaning, we advise you to put a couple of hundred BBs through your AEG to clear out any residual silicone lubricant. This will affect accuracy, especially if it has made its way to your HOP rubber

  6. Under no circumstances should anything other than 100% silicone oil be used, as other lubricants, such as WD40 will severely damage the rubber air seal components inside the AEG, rendering it unusable.

As an alternative, some players choose to use a degreasing spray to clean their inner barrels, which is very effective but requires the barrel to be removed from the AEG to ensure no excess degreaser makes its way into the gearbox. Using a degreasing spray can be especially useful if you haven't cleaned your inner barrel in a while, or if you want to avoid having to fire a few hundred BBs through the AEG following cleaning to clear out the excess lubricant. 

Performance - Factors to Consider

Now that you know how to properly maintain your AEG, it’s important to understand other factors that can affect its performance. These are outlined below, so you can be aware of any changes or improvements you need to make

Projectile shape

There is a reason the so-called "Minié ball" and  "spitzer" bullet were invented in the post-musket era. The reason being, a sphere is not the best projectile to shoot as far as stability goes. Spherical projectiles are particularly vulnerable to air resistance, meaning their velocity will drop off much more sharply than a pointy projectile. Obviously, Airsoft guns come with HOP up units to stabilise the projectile and add a significant amount of effective range, which goes a long way to mitigating this. Equally obvious is the fact that we aren't actually trying to kill each other at a skirmish, and the less likely the projectile is to enter the skin, the safer it is. The airsoft BB is the perfect projectile for our sporting purposes, but that doesn't come without a trade-off. 


Due to the considerable difference in weight of an airsoft BB when compared to a real firearm bullet or even an Air rifle bullet means the BB suffers much more when shooting in windy conditions than the aforementioned projectiles. This doesn't mean you can bring your air rifle and dominate the Airsoft field though! 

The effects of windy weather can be mitigated by using heavy BBs, but the real benefit of heavier projectiles is only really seen in long-range set-ups, such as DMR rifles. This refers to rifles locked to semi-auto, permitted to exceed the velocity restrictions for fully automatic AEGs with a minimum engagement distance enforced.

BB weight

Your choice of BB weight can be a major factor in your AEG's performance. We recommend anywhere between 0.2g and 0.28g for the average AEG. 

For CQB and AEGs with less effective HOP, 0.2g is ideal, and they generally run a bit cheaper than heavier options. For outdoor skirmishes with longer engagement ranges, 0.25g is great, provided you adjust your hop to get the ideal trajectory. 0.28g and above are useful for DMR rifles or otherwise tuned rifles with a very strong HOP, as these are verging on sniper BB weights and probably will require a HOP up upgrade for optimum performance in most AEGs. 

Some support gunners also choose to run heavier BBs, as they provide improved penetration of foliage and light cover when nearing their maximum range, due to their mass allowing them to retain energy for longer. 

The downside to using heavier BBs is that your velocity will decrease, potentially to the point that the opposing force can see them coming and dodge., Plus, if your HOP is not strong enough you will see a reduction in range. Lighter BBs will get out there quickly, but at longer ranges you may find they are more affected by wind, impacts with leaves, and other foliage between you and your target.  Then, when you shoot and bag yourself a nice long-range hit, your target is less likely to feel it.


This is one of the biggest misconceptions in Airsoft. At UK legal velocities, there is very little benefit to squeezing an extra 20fps out of your AEG to get it from 330 to 350, especially before you have used your AEG and pinpointed its weaknesses.

Velocity upgrades are a risky business, as increasing the strength of the spring can put stress on other parts in the gearbox, often resulting in continual upgrades to keep your AEG working. The fact that many AEGs come with higher power springs before they are downgraded for UK legality means on average, UK velocity AEGs will last longer, provide a higher rate of fire and quicker trigger response. This is due to the reduced stress on the gearbox internals.  

We recommend that if your AEG shoots between 300 and 330fps, you will not really benefit from a velocity upgrade unless you are upgrading to DMR velocity. This is a big job and means you have to kiss goodbye to full auto.

A much more useful upgrade at these velocities would be a HOP upgrade, providing increased range and projectile stability. It is well known that Tokyo Marui AEGs and GBB pistols have exceptional HOP units providing superb BB trajectory stability, so they out-range cheaper AEGs shooting 400fps whilst they shoot well south of 300fps. Whilst the fabled Tokyo Marui "magic dust" probably isn't real, the benefits of a well set up HOP and correct BB weight choice absolutely are. 


The trajectory of the projectile is definitely something new players are often not aware of. 

Due to the laws of Physics (we love those!), a projectile without any spin when fired horizontally will hit the ground at the same time as the one you drop straight down from the same height. HOP is used to counter this, providing not only stabilization in lieu of a rifled barrel but also back-spin to increase the range.

The side effect of this is an extremely sudden drop-off at the end of the HOP-extended flight path, as the spin slows and air resistance eats up the muzzle energy of the BB. The consequences, as it relates to a skirmish, is that it may appear that you are landing hits on a target near maximum range when in actual fact your BBs are falling straight down at their feet.

A good way to gauge this phenomenon is to either get shot at (the painful choice) or get a friend to stand at the edge of your AEGs range and watch the flight path. Even with an optimally set HOP, this will happen, and there are no upgrades that can prevent it. In order to avoid frustration and assumptions that the target didn't call the hit, it can be useful to be aware of this. 

And here ends our guide on what to expect from your AEG and what you have to do to keep your AEG happy. We hope you have learned what you need in order to appreciate the innovation and technology that is present in these RIFs, and that you now understand both the capabilities and limitations of the Airsoft AEG as a platform. 

To learn more, be sure to check out our other handy guides such as What is an Airsoft Gun.