Umarex Fusion 2 CO2 rifle: Part 3

by Tom Gaylord
Writing as B.B. Pelletier

Fusion 2
Umarex Fusion 2 CO2 repeater.

Part 1
Part 2

This report covers:

  • A dime spacer
  • It worked!
  • Velocity
  • No feeding problems
  • Trigger pull
  • One final tip
  • Where we stand
  • Summary

Today we look at velocity of the Umarex Fusion 2 repeating air rifle again. After Part 2 I considered all the remarks carefully. I wanted to test the rifle’s accuracy but not before knowing how many shots I could count on.

A dime spacer

Reader EricfromSC said he used a dime as a spacer between the two CO2 cartridges and it worked. He also mentioned that he had the same magazine feeding issues I encountered and that by holding the rifle level when working the bolt they were resolved. When I test velocity I often cock the rifle with the muzzle up, so this time I was careful to hold it level. read more

Endosnake borescope

by Tom Gaylord
Writing as B.B. Pelletier

The Endosnake is an affordible endoscope/borescope that works with a smartphone or computer. The camera has mini LEDs to illuminate what’s in front of it.

This report covers:

  • A job worth doing…
  • First use
  • Videos not necessary
  • Resolution
  • Summary

For years I have wanted a borescope so I could look inside my barrels. Twenty years ago they were priced in the thousands and out of my reach. Ten years ago they dropped into the hundreds and were still pricy. But they were not optimized for airguns. They were mostly sized for .22 barrels, as though AR-15 owners were the target market. Again, I had no interest.

Then about two months ago I started getting emails about a product called the Endosnake. It was selling for $50 and I needed a wifi kit to connect it to my iPhone. I got the one that’s 2 meters long. The camera is 3.9mm in diameter and when I asked the Endosnake people whether it would fit into a .177 caliber airgun bore they said they didn’t know. Well, I know now and it does! read more

Slavia 618 breakbarrel air rifle: Part 1

by Tom Gaylord
Writing as B.B. Pelletier

Slavia 618
Slavia 618.

History of airguns

This report covers:

  • History
  • Research
  • Model variations
  • What is the Slavia 618?
  • Comparisons
  • Stock
  • Summary

Some of you may have been hoping for Part 2 of the Beeman R10 rifle report today. Well, Part 2 will be the strip-down and installation of the Vortek tuning kit, and I need a couple days to do the work and take the pictures, as well as the writing. So today I’m starting my report on the Slavia 618 breakbarrel pellet rifle.


Guess what? Almost nobody knows the history of this air rifle. It has a lot of fans, but nobody seems to know much about it.

The Blue Book of Airguns says it was made in the 1970s — period. But they say the same thing about the Slavia 622. Well, I received one of those as a gift in about 1961 or ’62, so that’s obviously not right. read more

AirForce Edge 10-meter target rifle: Part 3

by Tom Gaylord
Writing as B.B. Pelletier

AirForce Edge.

Part 1
Part 2
Part 3
Part 4
Part 5
AirForce Edge 10-meter target rifle: Part 1
AirForce Edge 10-meter target rifle: Part 2

A history of airguns

This report covers:

  • Accuracy day
  • Dropped a shot
  • What was happening?
  • The problem
  • Went to AirForce
  • Adjusting an Edge top hat
  • Purpose of the o-rings
  • Adjusted the top hat
  • RWS Basic
  • H&N Finale Match Light
  • RWS R10 Match Pistol
  • Sig Match Ballistic Alloy
  • Shot count
  • Off the regulator
  • One last thing
  • Summary

Oh, boy! Every once in awhile something big happens with this blog, and today is a report on such a time. This is about the AirForce Edge.

To tell the complete story I first have to tell you some bad news. I want you to read it without getting angry, because if it hadn’t happened as it did I would not be able to tell you the extraordinary news I’m about to tell you.

Accuracy day

This report was supposed to be the first test for accuracy. I knew there were going to be several accuracy tests, but this would be the first one. Except the rifle didn’t cooperate. read more

A little about o-rings

by Tom Gaylord
Writing as B.B. Pelletier

An assortment of o-rings.

This report covers:

  • History
  • Flexibility is key
  • O-ring failure
  • O-rings as a face seal
  • O-ring-assortments
  • Hardness
  • Some o-ring facts
  • The seats or channels they sit in help o-rings work!
  • O-rings used other ways
  • Summary

An o-ring is a donut-shaped elastomer (pliable) seal that performs sealing functions for hydraulics and gasses. Airguns use o-rings a lot, and for different purposes. They help us enjoy our hobby with a minimum of fuss. But what do we know about them?


The first patent for an o-ring was by the Swedish inventor, J.O. Lundberg. It was granted in 1896. Not much is known about him, but Danish machinist, Neils Christensen who came to the U.S. in 1891, patented the o-ring in this country in 1937. No doubt his work originated from his development of a superior air brake that Westinghouse, a leader in air brake technology since George Westinghouse invented the first fail-safe railroad air brake in 1869, gained control of. In World War II the U.S. government declared the o-ring a critical mechanical seal technology and gave it to numerous manufacturers, paying Christensen a stipend of $75,000 for his rights. Long after the war was over and he had passed away his family received another $100,000 read more

AirForce Edge 10-meter rifle: Part 5

by Tom Gaylord
Writing as B.B. Pelletier

AirForce Edge
AirForce Edge.

Part 1
Part 2
Part 3
Part 4

This report covers:

  • Behind the curtain
  • Field measurements
  • Test 
  • Low velocity
  • Different valve
  • H&N Finale Match Heavy
  • RWS Meisterkugeln Rifle
  • Shot count
  • Short on air?
  • Hammer spring
  • What else have I learned?
  • Summary

Today is unusual because I’m doing a back-to-back report on the AirForce Edge. I don’t normally do that, but I discovered some very interesting things that will probably help a lot of you with precharged pneumatic airguns of any kind. Also, I got into this project and just couldn’t stop until it was finished. I know you know what that’s like. Let’s get to it.

Behind the curtain

There were several things I did not tell you in Part 4 last Friday. I did them then, but the results were outside the scope of the report, so I held off. Today they will make a lot more sense. read more

Some talk about airgun lubrication: Part 1

by Tom Gaylord
Writing as B.B. Pelletier

This report covers:

  • Why do we lubricate?
  • The Meteor’s needs for lubrication
  • Leather piston seals
  • Velocity
  • Watch the performance
  • Synthetic piston seals
  • Summary
  • Other lubrication requirements

Yesterday a reader asked why I bothered with Tune in a Tube. Why didn’t I just clean the Meteor Mark I when I had it apart, lubricate with moly grease and be done with it? That tells me there are a number of readers who don’t really understand what is involved with airgun lubrication. So today I thought I would discuss it a little.

Why do we lubricate?

This is a good place to start. In fact, from the reader’s comments, it seems to be at the core of misunderstanding. Don’t we just lubricate to reduce friction?

Friction is a principal reason for lubrication. But there is more to it than that. Sometimes we want to reduce friction by a certain amount, while retaining some part of it that’s needed for proper operation. Otherwise, moly (molybdenum disulphide) would be the answer to everything. Some airgunners think it is. The reader who wrote the comment that got me started on today’s topic said that very thing — that I should just clean the Meteor’s parts and lube everything with moly and be done with it.

That would be a disaster! Let’s look at that airgun and see why.

The Meteor’s needs for lubrication

The Meteor was buzzing when it fired. Buzzing is caused by excessive tolerances that allow the powerplant parts to vibrate when the gun fires. Moly will have no affect on that. The parts may move faster than they did before when lubed by moly, but they will still bang together and vibrate in an annoying way.

What is needed is one of two things. Either the parts must be tightened in some way so there is less sloppiness or they must be surrounded by a material that causes the vibration to stop quickly. Tune in a Tube does the latter. While it does provide lubrication, the ability to stop vibration is its principal feature. Add to that the fact that it can be applied to a gun without disassembly and you have a wonderful product for a spring piston airgun. And a mediocre one for a CO2 or pneumatic gun, whose needs for lubrication are different.

I will address those other powerplants later in this series. Let’s stay with the Meteor for now. The Meteor is made as cheaply as it can be. Its piston is sheet metal that’s formed into a cylinder and welded, top and bottom. That kind of construction does not lend itself to the attachment of synthetic bearings called buttons, which are the number one way to eliminate slop for a piston . You saw me use buttons on the piston of the Diana 45 I tuned in the special 10-part series I did last year. Part 6 of that series shows most of the tricks I would normally use to tune a spring gun, but the Meteor’s thin metal construction doesn’t allow most of them. Because of that, Tune in a Tube is an ideal product for the Meteor. The intended use is a large part of selecting the correct lube.

For the Meteor piston, piston seal and mainspring I need a lube that will dampen vibration, reduce friction and also seal the compression chamber. Tune in a Tube with do the first two, and oil will seal the compression chamber. But — what kind of oil? The Meteor has a leather piston seal, so let’s discuss that first.

Leather piston seals

Leather piston seals need to be flexible to seal the compression chamber. That takes oil. Is the oil a lubricant? Yes, but in this case it’s being used for three good reasons. First, because it keeps the leather seal pliable, allowing the leather to flex and to therefore seal the air in front of it. Second, being oil, it lubricates the seal, reducing friction so the seal and the piston it’s mounted on will move as fast as possible. And third, being oil, it evaporates slowly, which means the seal will stay pliable longer. But longer than what? Well, longer than water, for example.

Water will lubricate the leather and make it pliable. A water-soaked piston seal will seal the compression chamber about as well as one soaked in oil. But water evaporates rapidly and will dry out. When it does, the leather will shrink and harden. If left that way, it will break up in small particles every time it is moved, as in firing. And, if left for long enough it will eventually dry completely, allowing the leather to deteriorate by a process we call dry rot. Oil may dry to a point, but even when appearing dry some will remain for years, preserving the leather if it isn’t worked too hard. I have seen the leather seals in airguns that were over one-hundred years old, and they were still in working condition because they had been oiled.


The velocity of the airgun also plays a factor in the choices for lubricants. The Cardews showed in their experiments that were documented in the book, <i>The Airgun from Trigger to Target</i>,       that when a spring piston airgun approaches 600 f.p.s. muzzle velocity it starts burning some of the lubricant in the compression chamber. That is called dieseling. Like any other internal combustion engine, this burning of oils generates energy of its own. In an experiment the Cardews shot a 14.4-grain .22-caliber pellet in an HW 35 at 636 f.p.s. when the gun was properly lubricated. When the same gun was fired in a pure nitrogen atmosphere where combustion was not supported, the same pellet only shot 426 f.p.s. This proved that combustion was generating part of the energy in that airgun.

My BSA Meteor Mark I shoots light lead pellets at greater than 600 f.p.s. So it is safe to assume that it, too, is dieseling with every shot. If water was used on the leather seal, the gun couldn’t diesel and the resulting velocity would be much slower. But consider this. If I used a type of oil that combusts readily, such as one made from petroleum, the gun might go from dieseling to detonating, which means exploding with every shot.

Therefore, for guns that shoot in the high 400s to the mid-500s, like Diana 25s and 27s, I recommend a piston seal oil that’s petroleum-based, like Crosman Pellgunoil. For guns that approach 600 f.p.s. and more I recommend high-flashpoint silicone chamber oil. Now you know the answer to what oil to use in a spring gun that you suspect has a leather piston seal. It’s based on the gun’s potential velocity, and if you don’t know what that is, watch the performance of the gun after you oil the piston.

My final comment about water on leather seals — don’t do it! That was mentioned for the purpose of discussion, only. Water inside a spring gun would rapidly oxidize and cause the gun to rust.

Watch the performance

If the gun you have oiled smokes after each shot without any noise, you are using the right type of oil on the piston. It may detonate a few times at first, but two or three explosions is all you should hear. If it keeps on exploding, you used the wrong type of oil. Since the seal is leather, just wait a few months, then oil it with silicone chamber oil from then on.

Synthetic piston seals

The oil for synthetic piston seals does something different than the oil for a leather seal. A modern synthetic seal is self-lubricating, which really means that the seal material has a very low coefficient of friction. It doesn’t need oil to work its best — at least not from the standpoint of friction.

A synthetic seal uses oil as an additional air barrier between the edge of the seal and the compression chamber. Like the oil in your car’s engine, the oil in your airgun compression chamber just makes the piston seal better. Don’t use too much oil, though, because the act of firing will vaporize some of the oil and cause it to detonate inside the compression chamber.

Synthetic seals come in all modern airguns, but since most of them shoot faster than 600 f.p.s., I advise everyone to use silicone chamber oil for their seals. It saves me having to explain all that is in this report, every time I talk to a new airgunner.


Today we have discussed lubricants used for two purposes. The first is to reduce vibration between moving parts in a spring-piston powerplant. And the second is to lubricate the piston seal.

When it comes to the piston seal we discussed the three purposes for oiling leather piston seals, and what types of oils work best. We learned that it depends on the power the gun produces. We also discussed what lubrication does for synthetic seals, and how that differs from the needs of leather piston seals.

I held nothing back today. If this report put you to sleep, my advice is to have someone else tune your spring guns. And, I’m just getting started. There are other lubrication requirements that deserve a thorough presentation as well.

Other lubrication requirements

Sealing pneumatic and gas reservoirs and valves
Reducing friction on metal parts
…heavy wearing parts like linkages
…piston bodies and spring guides
Oiling pellets

As you can see, there is a lot to lubricating airguns, and I plan to tell it all.