Chinese B3 underlever: Part 7

by Tom Gaylord
Writing as B.B. Pelletier

B3
The B3 underlever from China.

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

A history of airguns

This report covers:

  • Refresher
  • The test
  • Sig Match Ballistic Alloy
  • Sight adjustment
  • On a roll?
  • Air Arms Falcon
  • POI change
  • RWS R10
  • Best for last
  • JSB Exact RS
  • Summary

Today was day of learning, or perhaps I should say remembering, because today’s test of the Chinese B3 underlever took me back to my early days with spring-piston air rifles. I will explain as the report unfolds.

Refresher

I found this tired old air rifle in a pawn shop many months ago. In this series I have replaced the breech seal with a faucet washer, opened up the powerplant, lubricated the moving parts with Tune in a Tube and shot the rifle for accuracy. That was when I discovered how accurate this old Chinese underlever is. So I vowed to shoot it for accuracy once more, now that the powerplant has been tamed. read more


Beeman R9 with Vortek center-latching air piston: Part 4

by Tom Gaylord
Writing as B.B. Pelletier

Part 1
Part 2
Part 3

This report covers:

  • Important discovery!
  • Analysis
  • Setup
  • JSB Exact
  • Evaluation
  • Test restructure
  • Predator Polymag
  • H&N Field Target Trophy
  • H&N Baracuda
  • Crosman Premier
  • Benjamin Cylindrical
  • Velocity comparison
  • Retest of JSB Exacts
  • Cocking effort
  • Discussion
  • Going forward
  • Testing new designs

Today I will test the Vortek Center-Latching Air Piston in the Beeman R9, with the pressure set at 50 bar, which is 725.19 psi. This is the highest pressure to which I have set the unit, so today’s velocities should be the fastest we will see.

Important discovery!

Before we begin today’s test, a remark made by reader GunFun1 to the last report triggered some unplanned testing that revealed some surprising results. He was concerned by my remark that some spring-piston guns (and that is EXACTLY what this center latching unit is) need a “wake up” shot when they are first fired. I have seen this with perhaps half of the springers I have tested over the years. Here is what he asked me. read more


Beeman R9 with Vortek center-latching air piston: Part 3

by Tom Gaylord
Writing as B.B. Pelletier

Part 1
Part 2

This report covers:

  • Adjust the pressure
  • Filling
  • R9 disassembly and assembly
  • JSB Exact
  • Predator Polymag
  • H&N Field Target Trophy
  • H&N Baracuda
  • Crosman Premier
  • Benjamin Cylindrical
  • Discussion
  • Trigger
  • Cocking effort
  • Evaluation

Today we look at adjusting the Vortek Center Latching Air Piston, which I refer to as the center-latching unit (CLU). It went faster and easier than I imagined.

Adjust the pressure

To adjust the air pressure in the unit I had to disassemble the Beeman R9, to get the unit out. That procedure is described in Part 1. Once the unit is out, the piston seal has to be removed to reveal the air port.

Beeman R9 CLU port
Looking down into the fill port of the CLU we can see the ball valve.

To adjust the pressure in the CLU, first release all the air. That way you start from zero. The unit fills very fast from a hand pump and this is the best way to ensure accuracy. read more


Chinese B3 underlever: Part 6

by Tom Gaylord
Writing as B.B. Pelletier

B3
The B3 underlever from China.

Part 1
Part 2
Part 3
Part 4
Part 5

A history of airguns

This report covers:

  • Pre-work baseline
  • RWS Hobby
  • Harsh firing cycle
  • Rifle is breaking in
  • Air Arms Falcon
  • Sig Match Ballistic Alloy
  • RWS Hobby again
  • Discussion
  • Cocking effort
  • Trigger pull
  • Summary

Today I will test the velocity of the B3 underlever that we cleaned and lubed on Friday. This will be a fantastic learning lesson for all airgunners, because the results are most informative!

Pre-work baseline

If you have been following this report you know I discovered in Part 2 that the rifle wasn’t performing to expectations. In Part 3 I replaced the breech seal and tested the velocity. That gave us a baseline we can use today for a before and after comparison. Let me get to the tests right now.

RWS Hobby

The first pellet to be tested was the RWS Hobby. In Part 3 Hobbys gave an average 617 f.p.s. with a 24 f.p.s. spread. read more


Chinese B3 underlever: Part 5

by Tom Gaylord
Writing as B.B. Pelletier

B3
The B3 underlever from China.

Part 1
Part 2
Part 3
Part 4

A history of airguns

This report covers:

  • Remove the stock
  • Anti-beartrap
  • The piston and sliding compression chamber
  • Removing the mainspring
  • Removing the anti-beartrap device
  • Compression chamber and piston out
  • Cleaning
  • Assembly
  • The trigger
  • Lubrication
  • Does it work?
  • Next
  • Summary

Today I take the Chinese B3 underlever rifle apart and we see inside. This will be a good one.

Remove the stock

The first step is to remove the stock. That’s two forearm screws and one in the triggerguard. Once out, I could see this rifle is very rusty. It’s so rusty that it will take many hours to clean. I don’t have that kind of time so I’m going to clean only what needs to be cleaned.

B3 action
With the action out of the stock you can see rust everywhere! Notice the flat bar in front of the trigger housing. That’s the anti-beartrap. read more


Beeman R9 with Vortek center-latching air piston: Part 2

by Tom Gaylord
Writing as B.B. Pelletier

Part 1

This report covers:

  • Today’s fill
  • JSB Exact
  • Predator Polymag
  • H&N Field Target Trophy
  • H&N Baracuda
  • Crosman Premiers
  • Benjamin Cylindricals
  • Cocking effort
  • Trigger pull
  • Firing behavior
  • Summary

Today is velocity day for the Beeman R9 with the Vortek center-latching gas piston that I’m calling the center latching unit (CLU). Bear in mind as you read today’s test, that this unit allows the owner to adjust the pressure inside the gas piston — raising or lowering the velocity and cocking effort. So, this is the first of several tests of the unit.

Today’s fill

I filled the CLU to 675 psi when I installed it. So that’s how it’s set up today. I will test it with 6 different .20 caliber pellets — one more than Pyramyd Air carries, if you don’t count the felt Beeman cleaning pellets. Let’s get started. read more


The world’s best airgun doesn’t exist…

by Tom Gaylord
Writing as B.B. Pelletier

A history of airguns

This report covers:

  • The start
  • The deal
  • The challenge
  • It is achievable
  • The Marauder
  • Good points
  • Bad points
  • Bronco
  • The world’s best air rifle
  • Synthetic stock
  • The deal
  • History?

…but it has in the past. Or parts of it have existed. They are very rare today, but at one time there were many airguns that were 80 percent of the way to being great.

The start

This report started this past Wednesday in an archery store. Next week I will mention why I was in the store, but here’s what happened. The older man behind the counter, after learning what I did for a living, asked me what would be a good airgun for him to get. I stood there like a deer in the headlights, running through a half-century of experience and trying to boil it down to one sentence, when he added, “…and be able to take out a squirrel once in awhile.” read more