by Tom Gaylord
Writing as B.B. Pelletier

Gamo Swarm Fusion
Gamo Swarm Fusion 10X repeating rifle.

Part 1
Part 2

This report covers:

  • Today’s test
  • The test
  • Trigger adjustment
  • Sight-in
  • Air Arms Falcon
  • H&N Match Green
  • Gamo Master Point
  • RWS R10 Pistol
  • Firing behavior
  • JSB Exact 8.44-grain domes
  • H&N Baracuda Green
  • JSB Exact Heavy
  • JSB Exact RS
  • Firing behavior
  • Whew!
  • 10-shot group with Match Green
  • Conclusion?
  • Summary

Today we start looking at the accuracy of the Gamo Swarm Fusion 10X Gen II repeating breakbarrel spring-piston air rifle. I’m hoping for a great result!

Today’s test

The Swarm Fusion has open sights, and I’m testing them today. It also comes bundled with a scope that I will test in another report. Since this is the first accuracy test, I decided to just shoot 5-shot groups so I could test lots of different pellets. Let’s get started.

The test

I shot off a sandbag rest at 10 meters. I used a modified artillery hold, because the thumbhole stock on this rifle doesn’t permit a classic hold. The only difference is I did grasp the pistol grip.

I rested the rifle on the flat of my open palm with the heel of my hand back by the triggerguard. A rifle that recoils like this cannot rest directly on a bag or anything else!

I made no attempt to adjust the sights throughout the test until the very end. So, after sight-in the pellets went where they wanted to.

Trigger adjustment

I told you in Part 2 that I would buy a long-bladed small Phillips screwdriver to adjust the stage two trigger pull. After I had placed the order, reader New To Old Guns told me the second stage is already adjusted as short as it can be. Nevertheless, when the screwdriver arrived I tried adjusting it.

Gamo Swarm Fusion trigger
Don’t bother trying to adjust the second stage of the trigger. I did and there was no change.

NTOG was right, there isn’t anything you can do to the second stage. I adjusted it several times and found no difference. Well, at least I now own a nice set of long-bladed screwdrivers!


Since I was shooting with the installed open sights I started shooting at 10 meters. The first shot went high and I discovered the rear sight was adjusted up quite far. That was something I’m sure I did when examining the rifle. I adjusted it down and was on target in three shots.

Air Arms Falcon

The first pellet was the Air Arms Falcon. Four went into a tight 0.245-inches, but the fifth pellet opened it to 0.656-inches between centers at 10 meters. Maybe this pellet is worth further exploration.

Swarm Fusion Falcon group
Air Arms Falcons were tantalizing. Four are in 0.245-inches, but the fifth shot opened it to 0.656-inches at 10 meters.

H&N Match Green

Next up were H&N Match Green pellets. Every one of the five shots broke the sound barrier with a loud crack. But they were accurate! Five made a group that measures 0.341-inches between centers.

Swarm Fusion Match Green group
The Swarm Fusion sent 5 H&N Match Green pellets into a 0.341-inch group at 10 meters.

Gamo Master Point

I tried five Gamo Master Point pellets next. Four went into a nice 0.519-inch group at 10 meters, but the fifth shot opened it to 1.19-inches.

Swarm Fusion Master Point group
Four Gamo Master points went into a nice 0.519-inch group, but the fifth shot opened the group to 1.19-inches at 10 meters.

When something like this happens while I’m shooting with open sights I wonder if it was me that threw the shot. The other thing I wonder is if there is a bad chamber alignment in the mag that causes one shot to go wild like this.

RWS R10 Pistol

Next I loaded 5 RWS R10 Match Pistol pellets into the Fusion magazine. They went into 0.519-inches at 10m meters. Another good group!

Swarm Fusion R10 Match Pistol group
Five RWS R10 Match Pistol pellets went into 0.519-inches at 10 meters.

Firing behavior

At this point I will tell you that the Swarm Fusion does slap me in the face just a little when it fires. It’s not much but I can feel it. I will also tell you that the trigger now acts very much like a light single-stage trigger. It’s easy to use but the let-off point is vague.

I’m not telling you this to discourage you. This rifle seems to be a winner in most respects. You just need to know what you are getting.

JSB Exact 8.44-grain domes

The next pellet I tried was the JSB Exact 8.44-grain dome. The Fusion 10X put five of them in 0.889-inches at 10 meters. This is perhaps not the pellet for the Swarm Fusion.

Swarm Fusion JSB Exact group
At 10 meters the Gamo Swarm Fusion put 5 JSB Exact 8.44-grain domes into a group that measures 0.889-inches between centers.

H&N Baracuda Green

The next pellet I tried was the 6.48-grain H&N Baracuda Green. They did not go supersonic, thankfully. Five went into a 0.708-inch group at 10 meters.

Swarm Fusion Baracuda Green group
The Fusion put 5 H&N Baracuda Green pellets into a 0.708-inch group at 10 meters.

JSB Exact Heavy

The next pellet I tested was the JSB Exact Heavy dome. The Swarm Fusion put 5 of them into exactly 0.40-inches at 10 meters. That is a nice result!

Swarm Fusion JSB Exact Heavy group
Five JSB Exact Heavy pellets went into 0.40-inches at 10 meters.

JSB Exact RS

The final pellet I tested was the JSB Exact RS dome. These are sometimes surprisingly accurate. But in the Fusion I had four that were close and one that was a flier. Four are in 0.472-inches, with five in 0.881-inches.

Swarm Fusion JSB RS group
Five JSB Exact RS pellets went into 0.881-inches at 10 meters.


That’s 8 pellets tested in the Gamo Swarm Fusion 10X rifle. There was never a bobble in feeding the pellets, so that magazine works quite well. Of course today was shot with open sights and there is a scope test coming, so we are not finished with the Fusion. However, I did want to shoot a 10-shot group with the most accurate pellet which turned out to be the H&N Match Green pellets. That’s too bad for a couple reasons. One, they are wadcutters and probably won’t hold up at 25 yards. And two, they are supersonic and very loud to shoot. But they were the best so I picked them.

Looking at where they hit the target I adjusted the rear sight for them. I went two clicks to the left and three clicks up.

10-shot group with Match Green

Ten H&N Match Green pellets went into 0.739-inches at 10 meters. Since open sights were used, that is a terrific result! The sight adjustment didn’t move the group very much.

Swarm Fusion 10Match Green group
Ten H&N Match Green pellets went into 0.739-inches at 10 meters.


This is an accurate air rifle. It’s a little harder to cock than an Umarex Synergis underlever repeater, and of course it costs more, but if you want power in a repeating breakbarrel, this is one to consider.

I will pare down the pellets I test at 25 yards, and I will also test 10 through the mag against the same 10 loaded singly. They still have to be loaded through the mag, but the same chamber is used every time.


We are not finished with the Fusion just yet. I still have to mount the scope and move back to 25 yards. Stay tuned!