Since the very nature of modelguns is to be able to re use the brass cartridges, cleanliness of the cartridges is essential to the reliability of the particular weapon. I have found that some cartridges do not have to be cleaned that often for the modelguns to work properly, these include the new type marushin MP40/uzi ones and most of the cartridges for the colt 45 range. other guns such as the Marushin M16/xm177 need the cartridges relatively clean for the long heavy bolt to be driven back enough.

A little wipe inside each time with a cotton bud dipped in wd40 is a good start, of course from the very corrosive nature of gunpowder products the cartridges MUST NOT be left for long periods of time without being cleaned, if this should occur you will be faced with a lot of stubborn and hard green deposits which is the brass being eroded away. Pull through pipe cleaners are a good investment and will keep your cartridges in tip top shape.

If you have a large amount of cartridges being used all the time it is worth investing in an ultrasonic cleaner .This uses ultrasonic waves making minute bubbles to break down any deposits inside cartridge. These devices are normally used in the Tatto and jewelry industry. I should have some of the ultrasonic cleaners available through my spare cartridges/caps pages.

The basic way shown in most of the modelgun manuals is to put used cartridges in a bowl of warm water with normal washing detergent, wipe them dry and spray with a light oil (wd40 is great for this) This is time consuming but essential for trouble free firing !