Airsoft Gas · Volume 6
Adapters, Silicone & Where to Buy
Overview
Volume 4 established the chemistry: green gas is filtered propane pre-mixed with silicone oil, and CO₂ arrives as a sealed 12-gram capsule. This volume is about the hardware that lets a builder feed those gases — specifically raw propane and bulk CO₂ — without paying the markup of pre-packaged airsoft “green gas.” The economics are the motivation: a can of branded green gas runs roughly $9–20, while a 16.4-oz camping-propane bottle holds far more usable gas for $3–6, with only a one-time adapter in the $5–35 range as a standing cost. The catch is that camping propane is dry — no silicone oil — and its bottle valve does not mate to an airsoft fill valve. The adapter solves both problems, and silicone-oil dosing becomes the builder’s responsibility rather than the gas manufacturer’s. The sections below cover the adapter hardware, the contested question of how much oil to add, the CO₂ tooling, where to buy, and the maintenance habits that keep seals alive.
6.1 Propane / Green-Gas Adapters
A propane fill adapter does two jobs. First, it bridges two incompatible fittings: it threads onto the CGA600 connection of a disposable Coleman-style 16.4-oz (1 lb) camping-propane bottle on one end and presents an airsoft magazine fill nozzle on the other. (Larger 20-lb tanks need a further adapter; airsoft fill adapters are sized for the small 14–16-oz throwaway bottles.) Second — on the better designs — it meters silicone oil into the charge as the gas flows, restoring the seal lubrication that camping propane lacks.
The reference product is the Airsoft Innovations “GunGas” adapter — and the brand name matters, because it is frequently miscalled “Power Up.” There is no Airsoft Innovations product by that name; the line is GunGas, made in Canada. The base GunGas Propane Adapter Kit ($17.20, approx, availability-dependent) ships with both a propane adapter and a duster adapter plus a bottle of premium silicone oil, and is manually oiled. The step-up GunGas High Strength adapter with Oil Pump Kit ($34.95) adds the design’s signature feature: the user pumps silicone oil into the propane bottle itself once, after which the bottle auto-doses oil into every subsequent fill for that bottle’s life — the cleanest way to guarantee consistent, light oiling without per-fill guesswork.
Against the GunGas sits a field of generic adapters, most using the simpler manual-oiling model: a small oil port near the nozzle into which the user drips oil before each fill. Examples include Evike’s polymer adapter (~$12–15, whose label instructs adding ~3 drops to the oil port before filling), Evike’s CNC-aluminum version, Sapien Arms units on Amazon, and Lancer Tactical’s full-metal pressure-activated adapter, alongside many unbranded CNC aluminum or stainless units built CGA600-to-GBB-nozzle. One persistent caution: all-metal probes can damage the soft fill valve of a GBB magazine, so several designs use a polymer or softer-tipped probe. (A frequently-cited Nine Ball / Laylax propane adapter could not be confirmed in research and is not asserted here.)
The practical distinction between the two camps is the oil reservoir: a built-in reservoir or oil-pump system (GunGas High Strength) doses automatically and consistently, while a manual-port adapter (most generics) leaves dosing entirely to the user’s habits — which is exactly where the controversy lives.
6.2 Silicone-Oil Dosing
Silicone oil is in the system for one reason: seal lubrication. Branded green gas carries it pre-mixed precisely because the O-rings, valve seals, and sliding surfaces inside a gas blowback gun need a light, continuous film to stay supple and gas-tight. Bare camping propane delivers none, so a propane-fed gun will dry out its seals over time unless oil is added back. That much is settled. How much to add is not.
The published guidance spans roughly a 15× range, worth presenting honestly rather than splitting the difference:
Table 1 — The published guidance spans roughly a 15× range, worth presenting honestly rather than splitting the difference
| Source | Dosing guidance | Confidence |
|---|---|---|
| Airsoft Innovations (manufacturer) | ~2 drops per 10 magazine fills | high |
| Generic Evike adapter label | ~3 drops per fill | high |
| Community / DIY figures | a few drops every ~7 fills; some add none, greasing parts directly | medium |
The conservative, defensible default is to lead with the manufacturer’s low end — on the order of a couple of drops per several fills, not per fill. The per-fill label figures are widely regarded in the community as far too heavy, and the consequences of over-oiling are real and specific: the hop-up bucking and inner barrel must stay oil-free to grip and spin the BB. Excess silicone oil migrates downstream onto the bucking and barrel, kills the friction the hop relies on, and produces inconsistent hop and wild, erratic flight — the classic symptom of a freshly over-oiled gun. It also gums internals and accelerates wear. Only the O-rings, valve seals, and sliding surfaces want a film; nothing forward of the nozzle does. When in doubt, under-oil and watch for the first sign of a dry or squeaky seal rather than dosing heavily on every fill.
6.3 CO₂ Adapters & Fill Tools
CO₂ splits into two delivery models. The dominant one needs no adapter at all: the gun takes a 12-gram threadless “powerlet” capsule that drops into the magazine and is pierced by a retention screw. There is nothing to fill — the capsule is the charge, good for roughly 40–60 shots before it’s spent and discarded. This is the path the overwhelming majority of CO₂ guns use.
The second model is the bulk-CO₂ fill adapter, which refills a CO₂-capable magazine from a larger source (a paintball-style bulk tank or refillable reservoir) rather than feeding it one disposable capsule at a time. These are a niche convenience for high-volume shooters; most CO₂ users simply buy 12-g capsules by the box. Either way the dry-gas caveat applies: CO₂ carries no oil, so CO₂ magazines need periodic manual silicone lubrication of their seals.
6.4 Best Adapters & Where to Buy
Propane adapters and fill tools sell through the usual airsoft channels — Evike, Airsoft GI, Amazon, Airsoft Megastore, Airsoft Station, Fox Airsoft, RedWolf, and Airsoft Innovations’ own store. Indicative pricing and stocking:
Table 2 — Propane adapters and fill tools sell through the usual airsoft channels — Evike, Airsoft GI, Amazon, Airsoft Megastore, Airsoft Station, Fox Airsoft, RedWolf, and Airsoft Innovations' own store. Indicative pricing and stocking
| Adapter / tool | Approx price | Where (typical) |
|---|---|---|
| AI GunGas Propane Adapter Kit | ~$17 | Airsoft GI, Airsoft Station, AI store |
| AI GunGas High Strength + Oil Pump | ~$35 | Airsoft GI, Airsoft Megastore |
| Evike polymer propane adapter | ~$12–15 | Evike |
| Evike CNC-aluminum adapter | ~$15–25 | Evike |
| Lancer Tactical full-metal adapter | ~$15–20 | Evike, Amazon |
| 12-g CO₂ capsules (per box) | ~$0.50–1 each | Evike, Amazon, Fox Airsoft |
All prices are approximate and availability-dependent — re-check at purchase time, because availability in this category is volatile. The Airsoft Innovations GunGas is excellent but frequently out of stock (multiple retailers and AI’s own store showed sold-out listings during research, with no sign of a permanent discontinuation — it reads as intermittent stock-outs and restocks).
Recommendation for most builders: if a GunGas High Strength with the oil-pump kit is in stock, buy it — the auto-dosing reservoir removes the single biggest source of per-fill error. If it is sold out (often the case), a generic polymer or CNC-aluminum adapter in the ~$12–15 band is the de-facto fallback and is essentially always available; just adopt the conservative manual-oiling discipline from the dosing section, and prefer a polymer-tipped probe to protect the magazine fill valve.
6.5 Maintenance
Three habits keep a gas system healthy. First, vent after play but not completely — the standard advice is to leave a little gas in each magazine so the fill valve and seals stay seated under slight positive pressure rather than fully relaxing; this protects against debris ingress and seal set. (For punctured CO₂ capsules the opposite urgency applies: do not leave a pierced capsule under full pressure in a magazine for more than a day or two, because sustained high pressure and cold cycling hardens and cracks O-rings.) Second, seal care is the silicone-oil routine above — a light, periodic film on O-rings and sliding surfaces, never on the hop or barrel. Third, storage: keep gas cans, propane bottles, and CO₂ capsules cool, dry, and out of direct sunlight, since heat raises internal pressure. And a transport note from Volume 4 bears repeating here — pressurized gas and propane generally cannot be shipped or flown, so plan to buy adapters mail-order but source the gas itself at the destination.