Seneca Dragonfly Mark 2 .177: Part Eight

Seneca Dragonfly .177.

Part 1
Part 2
Part 3
Part 4
Part 5
Part 6
Part 7

This report covers:

  • The plan
  • The test
  • Seven pumps
  • Eight pumps
  • Nine pumps
  • Ten pumps
  • However
  • Nine pumps free-floated
  • 8 pumps free-floated
  • 7 pumps free-floated
  • What to do?
  • Ten shots on ten pumps per shot free-floated
  • What’s next?
  • For Dragonfly owners

Today we have an unusual test to examine. It was supposed to be one thing and turned out to be another.

In April I shot the .177-caliber Seneca Dragonfly Mark 2 for accuracy at 25 yards, testing how the number of pump strokes affected the 5-shot group size. The pellet I used was the 10.34-grain JSB Exact Heavy. I tested accuracy at 25 yards on 3, 4, 5, and 6 pump strokes with this pellet. Six pumps proved to most accurate, putting five JSB Heavies into 0.69-inches.

My plan for today was to shoot the Dragonfly from 25 yards with the same pellet on 7 through 15 pumps. But things happened to change my plan and therein lies our report.

What happened may get a little confusing, so please read everything as we go. The .177 Dragonfly Mark 2 that has a UTG 3-12X32 Bug Buster attached. That scope was zeroed when it was mounted in Part 6, so today I shot a single JSB Heavy pellet on 7 pumps of air, just to “wake up” the rifle before starting the test.

The test

I’m shooting from 25 yards with the rifle resting directly on a sandbag. I’m shooting 5-shot groups until the end of the test. There were no called pulls that resulted in flyers throughout today’s testing.

Seven pumps

On seven pumps the Dragonfly put five pellets into a 25-yard group that measured 1.36-inches between centers. I was surprised at this group’s size, since on 6 pumps the rifle put five of the same pellet into 0.69-inches. But this is why we test.

Dragonfly 7pumps
On 7 pumps the Dragonfly put 5 JSB Exact Heavys into a 1.36-inch vertical group.

Eight pumps

On eight pumps the Dragonfly put five JSB Heavys into a 25-yard group that measures 0.855-inches between centers. At the time I thought this could be a turning point.

Dragonfly 8 pumps
On 8 pumps the Dragonfly put 5 JSB Heavys into a 0.855-inch group.

Nine pumps

On nine pumps the rifle put five JSBs into 1.691-inches at 25 yards. This was the point where today’s report changed. Something was wrong and I wasn’t sure what it was.

Dragonfly 9pumps
On 9 pumps the rifle put five pellets into 1.691 inches at 25 yards. Something was probably wrong and I needed to investigate.

I stopped shooting and looked inside the muzzle cap of the rifle for lead streaks. There were none, nor did I expect any since the hole through the muzzle cap is much larger than the exit hole at the barrel’s muzzle.

Then I went to all the previous reports, looking to see whether I had removed the muzzle cap and the front sight of this rifle, making the barrel free-floating. I could not find mention of that anywhere for this rifle, so it looks like I didn’t do it, but I did it for the .22 version when I mounted the dot sight and I believe I left it off for the remainder of the testing of that rifle. You can see how I removed that sight in Part 6 of the test of the .22 Dragonfly.

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Ten pumps

For ten pumps I removed the muzzle cap and the front sight — free-floating the barrel. If the next 5-shot group on ten pumps was much better I would go back and rerun the 7, 8 and 9 pump-strokes tests. I did adjust the scope 2 clicks to the left for this group. And naturally there was a HOWEVER.


On ten pump strokes per shot the first three shots went quite a bit higher than the bullseye aim point (2.5-inches) but they landed close together. Had I discovered “the secret”? Then shot number four went a lot lower. Phooey! But shot number five hit next to it, so I decided to keep on shooting to see if all the shots would now land together. Sure enough, they did!

So, what I have to show you for ten pumps per shot are 8 pellets in 1.555-inches between centers, with the last five (shots 4 through 8) in 0.383-inches between centers. 

Dragonfly 10pumps
This group caused me to rethink today’s test. Eight shots are 1.555 inches apart (between centers) with the last five 0.383-inches apart.

I wasn’t certain of anything at this point, but it did seem that the rifle might have settled down to group well, now that the barrel was free-floated. It also seemed like I needed to rerun the first three tests instead of pressing on with the number of pumps as originally planned.

I decided to rerun the first three tests in reverse order. No special reason for doing it that way except it kept me from becoming confused. I also adjusted the scope 10 clicks down to get the shots back on the bullseye at which I was aiming.

Nine pumps free-floated

This time on nine pumps the Dragonfly put five pellets into a 1.096-inch group.

Dragonfly 9pumps 2nd time
With a free-floated barrel the Dragonfly on nine pumps put five JSB Exact Heavy pellets into a 1.096-inch group at 25 yards.

This group is smaller than the previous group that was shot with 9 pumps. It’s not a great group but it is enough smaller to be considered significant. Let’s see what else happens with the other two tests.

8 pumps free-floated

On 8 pumps per shot with the barrel free-floated the Dragonfly put five pellets into a 1.221-inch group at 25 yards. That was significantly larger than the group that was shot with 8 pumps while the front sight was mounted. That one measured 0.855-inches.

Dragonfly 8pumps 2nd time
On 8 pumps with the barrel free-floated the Dragonfly put five shots into 1.221-inches at 25 yards. There are two shots in the lower hole.

7 pumps free-floated

On 7 pumps per shot the Dragonfly put five shots into 0.882-inches at 25 yards. This group is significantly smaller than the group shot with 7 pumps while the front sight was on the rifle. That one was 1.36-inches.

Dragonfly 7pumps 2nd time
On 7 pumps the Dragonfly with the free-floated barrel put 5 pellets into 0.882-inches between centers at 25 yards.

What to do?

It’s difficult to tell from these results whether free-floating the barrel helped or not. It seems like it did, but there isn’t enough data to tell for sure. However, since the barrel is free-floated I decided to end today’s test with a 10-shot group fired with ten pumps per shot. That’s might show us whether the small group we saw previously was for real or was just a fluke.

Ten shots on ten pumps per shot free-floated

My final target was a group of 10 JSB Exact Heavys shot with ten pumps per shot. While that group isn’t small, all ten pellets did land in 1.112-inches.

Dragonfly 10shots 10pumps
The Dragonfly with a free-floated barrel and on 10 pumps per shot put 10 pellets into 1.112-inches.

What’s next?

I think what comes next is to test the rifle on 11 to 15 pumps per shot. However, before I do that I believe I should put the front sight back on the rifle, to see if there is a difference with a 10-shot group while the front sight is on the barrel. If there is, then the front sight comes off again and I shoot the remainder of the test with the barrel free-floated. If not then the front sight remains on through the finish.

For Dragonfly owners

Today’s report may be of interest for the owners of Dragonflys in either caliber. I would test it if I was curious about my rifle’s accuracy.

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