Definitive Guide to Gamo Swarm Magnum, Gen 2

The Gamo Magnum started as an ultra-magnum break-barrel that boasted up to 1650 FPS with light alloy pellets. It later received the Whisper moderator, followed by the Swarm system later down the road. The original Swarm Magnum used the "tall" vertical mag system, which required Gamo to remove the open sights. The Gen II has been upgraded to use the rotating horizontal mag system and brings back Gamo's fully adjustable micro-click fiber optic sights.

Gamo's ability to create powerful but lightweight airguns continues with this version. The rifle comes in at only 6.8 pounds, making it an all-day carry around the woods gun. The thumbhole composite stock pulls easily into the shoulder and does not feel cheap. It is a long gun at 49.2", making it more suitable for larger shooters vs younger, smaller shooters.

The rifle sports all of Gamo's top technologies. It's powered by their IGT Mach 1 Gas ram, which promises more power with less recoil. We can agree that it produces excellent power, but in our opinion, the recoil remains fairly sharp. Fortunately, Gamo included their Recoil Reducing Rail (RRR) system, which helps protect the scope from the recoil and we've found this system to deliver on its promises. The recoil is further mitigated by their Shock Wave Absorber (SWA) recoil pad.

The trigger is Gamo's Custom Action Trigger (CAT), which is 2 stage adjustable. The trigger pull comes in around 3 to 4 pounds with a very light first stage followed by a smooth and predictable break at the end of the 2nd stage. As for adjustability, shooters can adjust the length of the 1st stage. The 2nd stage is fairly long, and while you can adjust it, you can only adjust it to be longer and not shorter. The pull weight is not adjustable.

We come now to what really sets this airgun apart, and that's the Gen II Swarm system and new inertia driven magazine system. As mentioned above, the Gen II Swarm System uses a horizontal magazine vs a vertical magazine. When you cock the gun, the magazine rotates into place so the pellet pusher can seat the pellet into the breach. When you close the barrel, it rotates back into place, allowing the use of the open sights.

The new magazine also has a trick up its sleeve. The old-style magazine utilized a spring that automatically rotated the magazine, lining up the next pellet for your next shot. This system works well, unless you accidentally cock the gun without taking a shot with the last pellet, leading to double-feeding pellets into the breach. The new magazine adds a mechanical stop to the process. The pellet will not advance until it feels the recoil and clicks the next pellet into place. The system works well, but in the event that it does not advance, you can hit the little red button and manually advance the system.

While the system incorporates the option to run with open sights, Gamo includes their 3-9x40 optic with a heavy-duty mount. It has a duplex reticle and a fixed parallax. We generally ding bundled optics pretty hard, but the Gamo Scope is actually pretty good. The parallax seems to be set for airgunners at around 35 yards. We've been unable to confirm the actual parallax distance, but from general use, it looks to be about 35 yards.

Before you start shooting, you need to load the magazine. This is done by inserting the pellet nose first and rotating the cylinder counter-clockwise until it clicks. Follow this process until you have loaded all ten pellets. Pay attention to the pellet length, as longer pellets may jam the system and prevent proper operation. Once fully loaded, install the mag into the Swarm System.

Make sure that you engage the safety located in front of the trigger within the trigger guard. Next, take a firm grasp of the moderator and, in one smooth motion, cock the gun. If necessary, be ready to use both hands as the cocking force is significant. We don't have the means to give you an exact number on what it takes to cock the Swarm Magnum, but we estimate that it's probably near 50 to 60 pounds. It's a lot, more than most break-barrels on the market.

The shooting cycle is very sharp. You will want to keep your cheek firmly planted on the stock, or it may rattle your teeth a bit. Once you understand how it all feels and what to expect, it's easy to make the adjustments. As with all spring/gas-ram airguns, the use of the artillery hold is essential. If you find your shots wandering vertically, then it may be that your off-hand position is not consistent.

Accuracy and Power

1650 FPS is a big number, and it's really not realistic. With lightweight lead pellets like the 7.0 Grain RWS Hobby pellets, we are getting about 1260 FPS. With the lightest lead-free pellets, we see that climb to about 1395 FPS. Now we are shooting at 4600 feet, which does impact our tests. The thinner air equates to less volume in the compression chamber, which will reduce the maximum velocity we'll get at this altitude.

**NOTE - The speed of sound will vary based on elevation. Once you start shooting over 1000 FPS you are getting close. When a pellet breaks the sound barrier you will get a "crack" that can't be quieted down. Also, accuracy generally suffers when you shoot pellets over the speed of sound. For the best accuracy shoot heavier pellets to keep your velocity under 1000 FPS.

For our accuracy tests, we looked at two pellets. The first is the 7.8 grain Gamo RedFire, and the 2nd is the 10.65 grain Baracuda Match. The IGT Mach 1 powerplant has plenty of power on tap to propel the heavier pellets which should equate to more energy and accuracy at longer ranges.

We did our tests at 20 yards and got the following results. The Gamo RedFire pellets gave us a .960" CTC 5 shot group shooting 1120 FPS which is 21.73 Ft-Lbs.

The H&N Baracuda Match pellets gave us a .496" CTC 5 shot group shooting 965 FPS which is 22.07 Ft-Lbs.

The RedFire pellets are ideal for small game hunting out to about 20 to 25 yards. The H&N pellets are ideal for stretching things out past 25 yards. There are many other pellet options, and every gun may like something slightly different, so make sure to try several options before you settle in on just one pellet.

Summing Up

Gamo has created yet another winner with their Swarm Magnum 10x Gen II. It certainly has its quirks, with the high cocking effort and sharp recoil. But the benefits, like massive power (for a break-barrel), 10 shot auto-indexing magazine, and outstanding accuracy, far outweigh the quirks. Add in a 5-year warranty and it's certainly an airgun worthy of attention.

If you have more questions, please reach out to us here at Airgun Depot, and we'll be happy to help you with anything you may need.