Hi-Capa R501/R603/R604 Long Magazine - Black [JAG Arms]

The one thing that everybody needs one in Airsoft. After some time one is not enough. And after some time two is not enough!! This one in particular is great cause it can hold many BBs!! Fast package and well delivered!

This looks so slick in the Pit Viper. Working flawlessly so far. It has of course higher capacity which is always good and just has a great tactical feel to it. It's a must to make sure you don't run out of ammo in the battlefield.

⭐⭐⭐⭐⭐ Hi-Capa R501/R603/R604 Long Magazine – Black [JAG Arms]

This long double-stack magazine converts a Hi-Capa into a persistent field tool. Construction feels sturdy. The increased tank capacity allows two or more full strings of fire per fill depending on gas and BB weight. The feed lips and spring provide reliable indexing with no hesitation. With the magazine installed the pistol sits a bit heavier and that extra mass actually improves recoil control and target follow-up when shooting fast strings.

Field performance: in both speedsoft and IPSC drills the longer mag reduced reload frequency dramatically. In real games I often only needed to reload once or twice per engagement period. Gas efficiency is excellent when paired with quality green gas and the mag’s valve holds pressure even in cooler conditions. Loading BBs takes slightly longer because the loader window is smaller, but that’s a minor tradeoff for the sustained shooting time it gives you.

Practical tips: carry a dedicated extended mag pouch or a modified pistol-mag pouch because standard pouches can be tight. Keep the fill valve lightly lubricated with silicone oil and avoid overfilling. If you move between platforms, double-check compatibility with non-JAG Hi-Capa variants; most users report cross-brand fit but always test before a match. Overall verdict: the long mag is a high-impact upgrade for anyone who wants capacity, gas economy, and steadier handling without sacrificing feed reliability.

Hi-Capa R501/R603/R604 Long Magazine – Black [JAG Arms]
Summary: Reliable, gas-efficient long mag that adds both capacity and stability – perfect for competitive use.

Review:
I purchased this long magazine for my Hi-Capa and it has been a fantastic upgrade. The build quality feels solid, with a strong feed spring and no wobble once inserted into the pistol. Gas efficiency is excellent: a full fill easily powers two full loads of BBs without leaks, even in colder weather. What I especially appreciate is that the extended size not only increases capacity but also gives the pistol a steadier grip for competitive shooting.
For anyone considering it: make sure to use high-quality green gas and keep the valve lightly lubricated, as this keeps performance consistent. If you want both reliability and extra firepower in a single package, this magazine is worth every cent.

Best magazines for hi-capa pistols! This will allow you to run around not worrying about having enough ammo to last the round. Works in all Hi-capa brands, no problems or concerns between brands. I also like the way this matches my black 2011s!

Fantastic magazine, holds lots of rounds and gas
Its not even that uncomfortable and looks great on the pistol.
If u use the pistol as a primary this is the way to go.
Might be too big for some pouches

Increased magazine for Jag arms pistols. I got it for my combat master and my sand Viper and it fits like a glove. The magazine has an increased tank of green gas and BBs and is great for extending the shooting session. The only flaw is that the loading window of the BBs is small and it takes a little longer to load the BBs but nothing impossible. Recommended

I have never used a green gas canister and I can tell you that it is really simple to use. This 1000 ml bottle is fantastic value for money and, despite almost 1000 shots fired, there is still gas inside. In addition, inside there is a small amount of silicone oil that will lubricate your replica. Recommended

Amazing magazine which is not much heavier than the standard sized one, the capacity is good enough to where in games where I am primarily using my pistol I only have to reload this big mag maybe once or twice per hour but this also depends on how much ammo you are looking to use.

I was afraid it would be clunky to carry around or have in the pistol but it actually is not any different than the small ones, you just have to get an extended pistol magazine pouch.