UMAREX Heckler & Koch HK USP 4.5mm BB 22-Round CO2 Magazine
Heckler & Koch Magazine
4.5 mm (.177) BB, 22 rds
22 shot magazine for BB's
Important — read before purchase or storage.
All CO2 and green‑gas/propane powered guns and magazines are pressure systems and must not be stored pressurised for any length of time outside active shooting. Leaving gas installed will compress internal seals, accelerate permanent leaks, and shorten the life of your gun.
Temperature & Pressure Behaviour
CO2 and propane are temperature‑sensitive: they expand and contract with temperature changes. That expansion can force gas past worn seals or, in extreme heat, rupture seals or valves — creating dangerous failures. Keep guns and magazines out of direct sunlight and away from heat sources. Cold temperatures reduce pressure and can cause low power or feed problems, so always test a gas gun in the conditions you intend to use it.Always remove or fully vent gas after use. If you’re not shooting, remove the CO2 capsule or vent/empty magazines. Do not store with gas installed.
Lubrication Recommendations
To protect internals and seals we recommend using gas with added lubricants:-
CO2: use lubricated CO2 capsules — UMAREX branded CO2 is our recommendation.
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Green Gas / Propane: use gas with added lubricant such as Vorsk, UltraAir, Nuprol, or Abbey (Green Gas).
Seal & Lubricant Guidance
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Apply one drop of silicone oil (for polyurethane seals only — usually green or clear seals) to the tip of every 5 CO2 capsules or before long‑term storage to lubricate the piercing nozzle and protect seals.
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For silicone seals (typically semi‑translucent white), only use PTFE‑based lubricants (e.g. Super Lube PTFE). Do not use silicone oil on silicone seals.
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Never use gas cartridges showing rust or visible corrosion.
Leak Expectations & User Responsibility
All gas systems will slowly leak over time. Proper care reduces the rate of leakage but cannot prevent it entirely. Leaving cartridges installed dramatically speeds up seal wear. By using or storing gas guns you accept responsibility for regular maintenance, correct lubricant use, and safe storage.We Test Before Sale
We test every gas‑powered gun prior to dispatch or handover for major leaks and function. This may mean the gun arrives with gas installed — you may choose to use this free gas or vent the gun before storage. Testing does not guarantee seal life or prevent future leaks; seals remain consumable parts.If you’re unsure about seal types, lubricant compatibility, or safe storage, ask us before purchase — we’ll give honest guidance. Failure to follow these recommendations may void warranty or return eligibility where damage is caused by improper storage or lubrication.
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