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Our goal is to fulfill orders and get them dropped off for shipping same day if ordered by 12PM EST or the following day. Worst case 2 days. If this does not happen with your order you are welcome to reach out to us via email at sales@blowbackmasters.com and we can guide you through why this was the case.

Please ship your return to the address below with the order number clearly displayed.

BBM RETURN (ORDER # )

2220 Executive Dr

Lexington, KY 40505

• All returns must be in new unused condition and in the original packaging. If not, you may only get partial refund.10% Restocking fee applied to all returns.
• Retuns must be initiated within 30 days of delivery.

Any concerns please feel free to contact us here: Contact Us

To increase fps on your hi-capa, upgrade your barrel and bucking combo. This upgrade improves FPS and accuracy. For even better consistency, consider upgrading the BlowBack Housing and magazine gasket.

Below are some good options to start your upgrade journey.

MAX FPS BUCKING

Best Inner Barrel

BEST FIRST UPGRADE KIT

Hands down the best hopup us the NEXXSPEED Hopup. Allowing top down adjustment to give the most consistent shot out of your pistol. 

Below is a link to the product and a video reviewing it.

Purchase NEXXSPEED Hopup

Review of the NEXXSPEED Hopup

This part of teh Hi-Capa is pretty sensitive. Check out the video below to learn about how to work on the sear to solve this solution.

How to adjust HI-CAPA sear spring to solve half cock

Building a Hi-Capa from Scratch is a journey we all want to explore.

Below is a link to a video showing how to do this step by step.

Video Tutorial

This is almost always a worn or dried-out O-ring in the fill or release valve, not a cracked magazine body. Common fixes, easiest first: 1) Make sure the valve is fully tightened - a valve key (or a well-fitting flathead in a pinch) snugs it down; a loose valve is the #1 cause of slow leaks. 2) Try the hot water trick - briefly warming the mag can reseat a swollen O-ring. 3) If it's still leaking, replace the fill valve and release valve O-rings. A full O-ring rebuild kit (fits most TM gas pistol mags including Hi-Capa) runs under $15 and takes about 10 minutes per magazine. 4) Avoid green gas with high silicone content long-term - it can swell o-rings unevenly; a PTFE-based lube on the o-rings helps them seal without gumming up the hop-up.

Short answer: this points to the magazine’s internal seal, not the fill or release valve — usually grit or a swollen main O-ring letting gas escape into the body instead of up through the valve.

How to fix it

1. Open the magazine and inspect the main seal for flattening, cracking, or debris.
2. Clean the seal and surrounding area with isopropyl alcohol.
3. Replace the seal if it looks worn — this is the most common cause.
4. Check the loading nozzle for hairline cracks too, since a cracked nozzle can mimic this same symptom.

If the leak continues after a seal replacement, the nozzle is the next thing to inspect.

Short answer: this is almost always the magazine lip or the loading nozzle not resetting fully — not a broken gun.

Two usual causes

• Magazine lip deformation — a bent or worn mag lip can snag BBs on their way up so they don’t present correctly to the nozzle. Swap magazines to test; if the problem follows the mag, that’s your answer.
• Nozzle not resetting fully — if the loading nozzle doesn’t travel back far enough each cycle, it won’t scoop the next BB. This is common after installing an aftermarket nozzle that isn’t a matched set with your hop-up bucking and chamber.

Stick to a matched nozzle/bucking/chamber set from one manufacturer to avoid this entirely.

Short answer: almost always a worn slide-lock notch, a stiff slide catch, or a weak magazine follower spring — in that order of likelihood.

What to check

• Worn or rounded slide-lock notch on the slide itself — very hard to see, but you can feel it by running a fingernail along the edge. Replace the slide stop if it’s rounded.
• Stiff slide catch — a drop of lube on the slide catch pivot can free it up if the magazine follower spring isn’t strong enough to push it up on its own.
• Weak or worn follower spring — try a different magazine to confirm; if the problem follows the magazine, replace the follower spring.

Step by step

1. Remove the magazine and confirm the chamber is empty.
2. Rack the slide back until the disassembly notch lines up with the slide stop — this exposes the hop-up wheel through the ejection port.
3. Turn the hop-up dial to add or reduce backspin. More hop suits heavier BBs, less hop suits lighter BBs.
4. Fire a few test shots and watch the BB’s flight. If it drops early, add a bit more hop. If it climbs and curves upward mid-flight, back off.

This applies to essentially all Hi-Capa-pattern pistols — Tokyo Marui, WE, Army Armament, KJW — since they share the same hop-up architecture.

Check these in order of likelihood:

1. Hop-up bucking wear or debris on the bucking’s contact nub
2. Inner barrel fouling — clean with a squeegee/pull-through and isopropyl alcohol
3. BB weight mismatch with your current hop setting (heavier BBs need more hop)
4. A poorly seated hop-up chamber after a rebuild

Rule out barrel fouling first since it’s the fastest, cheapest fix and the most common culprit.

Yes, this is normal — gas guns are temperature-sensitive by nature. Basic gas law: pressure rises with temperature.

A magazine that’s been sitting in direct sun will chrono hotter than one that’s been in shade or a cooler bag. For consistent readings:

• Let magazines acclimate to ambient temperature before testing
• Avoid firing many shots in a row right before chronoing — rapid-fire cools the mag and temporarily drops FPS
• Chrono at the same time of day/temperature you’ll be playing in whenever possible

Best option: install an adjustable/low-power gas valve (e.g. a Nine Ball High Power Gas Valve set to restricted flow). This lets you dial FPS up or down without permanently modifying the gun.

Other options

• Switch to a lower-pressure gas (duster/1.0 gas instead of green gas)
• Shorten the inner barrel slightly — even 1cm can meaningfully drop FPS, though this is more permanent and less reversible

An adjustable gas valve is the cleanest solution since it's fully reversible and lets you fine-tune for different fields.

Wipe down external moving surfaces and the barrel after every game day. For lubrication, match the product to the part:

• Airseal surfaces (piston cup, floating valve, air nozzle): light silicone oil
• Frame rails, hammer/striker assembly: a small amount of white lithium or PTFE-based grease
• Plastic-on-plastic or metal-on-plastic contact points: silicone oil, applied sparingly — over-lubing attracts dirt and can gum up the hop-up

Avoid petroleum-based oils on airsoft internals; they can degrade rubber seals over time.

Standard order

1. Clear the gun and remove the magazine
2. Rack the slide to the disassembly notch and remove the slide stop
3. Slide the upper assembly forward and off the frame
4. Remove the recoil spring/guide and barrel
5. For deeper cleaning, the blowback unit comes out after removing a single hex screw at the rear of the slide

Full teardown to the fire control group (hammer, sear, disconnector) is only needed for repairs, not routine cleaning.

Range and accuracy first. A quality hop-up bucking and tight-bore inner barrel give the most noticeable improvement for the money.

A common mistake is buying a metal slide before touching the internals — it adds weight and can actually slow cycling without improving accuracy. Save the metal slide for last, once the internals are dialed in.

Suggested order

1. Hop-up bucking + tight-bore inner barrel
2. Nozzle/bucking/chamber matched set if feeding is inconsistent
3. Recoil spring tuning
4. Metal slide and other cosmetic/aesthetic upgrades last

You can, but tolerances vary between manufacturers even though everything is nominally “TM-spec.” This is most likely to cause problems on the hammer/sear/disconnector set — mixing brands here is a common cause of light strikes or double-feeding.

When upgrading the fire control group, buy a complete matched set from one manufacturer (CowCow, Guarder, and Nine Ball are all reliable) rather than piecing it together from different brands.

Most Hi-Capa rear sights are drift-adjustable for windage and have a screw for elevation:

• Windage (left/right): the rear sight sits in a dovetail. Tap it gently left or right with a sight pusher or padded punch — move the rear sight in the direction you want the point of impact to shift.
• Elevation (up/down): if your rear sight has an elevation screw, turning it changes how high the BB hits. Not all stock sights have this — some are fixed, in which case elevation is tuned through hop-up instead.

Make small adjustments and re-test after each one; sight pushers are inexpensive and prevent scratching the finish.

Usually dirt or dried lubricant in the safety detent, not a broken part.

• Field-strip and clean around the safety lever and its detent ball/spring with isopropyl alcohol
• Apply a small amount of light lubricant (not grease, which attracts grit) to the pivot point
• If it's still stiff, check the detent spring for weakness or the safety lever itself for burrs

If your Hi-Capa has an ambidextrous safety, also check that both sides are engaging evenly — misalignment between the two levers is a common cause of stiffness.

Grip panel screws backing out under recoil is common on Hi-Capas. A few fixes, from simplest to most permanent:

• Apply a small dot of low-strength threadlocker (blue, removable-strength) to the screw threads before reinstalling
• Check that you're not overtightening — stripped threads in the frame hold worse than snug ones
• If the screw hole itself is worn, a slightly oversized replacement screw or a thread insert can restore grip

Avoid high-strength (red) threadlocker — it can make future disassembly very difficult on small grip screws.

Stock Hi-Capa slides don't come with a red dot cut, so you'll need one of these:

• RMR-cut slide — an aftermarket slide machined for a direct mount, the cleanest option if you're already upgrading the slide
• Optic mount plate — screws into the rear sight dovetail and sits the optic above the slide; works with a stock slide but adds height

Whichever route you choose, check that your chosen optic's footprint (RMR, Docter, etc.) matches the cut or plate before buying — footprints are not universal.

• Green gas: propane blended with a small amount of silicone oil for lubrication. Highest pressure of the common options, and the silicone helps seal O-rings over time — the standard choice for most players.
• Propane (duster/1.0 gas): similar pressure to green gas but without the added silicone. Runs cleaner on the hop-up but gives seals less lubrication over time, so o-rings may need attention sooner.
• Duster gas: significantly lower pressure, popular for lowering FPS to meet strict field limits or for indoor/backyard use. Requires a compatible fill adapter.

Whichever you use, avoid mixing gas types in the same session without fully venting the old gas first, since pressure differences can cause inconsistent shots.

Gas pressure drops with temperature, so cold weather is the #1 cause of weak, sputtering shots or a gun that won't cycle fully.

• Keep magazines in an inside jacket pocket between uses to keep them close to body temperature
• A magazine warmer pouch or hand warmer packet wrapped around the mag works well for extended cold-weather sessions
• Consider a higher-pressure gas (green gas over duster/propane) in cold conditions to compensate for the pressure drop
• Avoid leaving magazines in a cold vehicle or bag right before playing

If performance is still weak after warming the mag, that points to a mechanical issue rather than temperature.

Grittiness is usually friction, not damage. Heaviness is usually spring weight or geometry.

• Gritty feel: dirt or dried grease on the trigger bar/disconnector contact surfaces. Clean with isopropyl alcohol and re-lube lightly with PTFE grease.
• Heavy pull: stock trigger springs are often on the stiffer side. An aftermarket trigger spring kit (lighter trigger return spring) noticeably reduces pull weight.
• Inconsistent pull: check that the trigger bar isn't binding on the frame — light polishing of the contact rails can smooth this out.

A trigger job (polishing sear/hammer engagement surfaces) goes further but should be done carefully, as over-polishing can affect safety engagement.

Recoil spring weight is a tradeoff between slide speed, felt recoil, and reliable cycling:

• Lighter/stock spring: snappier cycling, more felt recoil, but can short-stroke on colder days or with weaker gas
• Heavier spring (110%–130%): smoother, more controlled cycling and better spring life, popular for players who want a more realistic recoil feel without sacrificing reliability
• Very heavy springs (150%+): only recommended with a matched high-flow nozzle/valve setup, otherwise the slide may not fully cycle

Start with a 120% spring as a good middle ground if you're unsure, and adjust from there based on how your gun cycles with your preferred gas.

Unlike a real firearm magazine spring, a Hi-Capa's BB follower spring doesn't wear out from being loaded — but it can weaken over years of use, especially if left compressed with BBs loaded for long periods between games.

• Signs it needs replacing: BBs not feeding reliably near the end of the magazine, or the slide not locking back on empty
• As a habit, unload magazines after each game day rather than storing them loaded — this significantly extends spring life
• Replacement springs are inexpensive and take a couple of minutes to swap

Mostly yes, with some caveats. WE, KJW, Army Armament, and most other Hi-Capa clones follow the same general dimensions as the Tokyo Marui original, and TM-spec aftermarket parts are designed around that standard.

• Slides, barrels, and hop-up units generally swap fine across brands
• Magazines are the most likely to NOT be cross-compatible — gas output and fit vary by brand
• Frame-level parts (fire control group) can have small tolerance differences that cause light strikes if mixed carelessly

When in doubt, check the specific part listing for confirmed compatibility with your platform (TM, WE, KJW, etc.) before ordering.

Common symptoms of a cracked loading nozzle:

• Gas leaking from the front of the slide/ejection port area rather than out the barrel
• Random drops in FPS or double feeding that doesn't correlate with the magazine
• A hissing sound on firing that doesn't match normal cycling

To confirm, remove the blowback unit and visually inspect the nozzle for hairline cracks, especially around the tip and the o-ring groove — this is a common wear point on stock plastic nozzles. If you see any crack, replace it; nozzles are inexpensive and a cracked one will only get worse.

This is a fairly simple issue. Below is a link to solve this issue.

Watch Tutorial

Maintaince is a must in keeping your GBB pistol operating properley.

Below is a video showing how to keep up with maintaince. 

Maintenance on an AAP01