The Benjamin Cayden: Part 2

by Tom Gaylord
Writing as B.B. Pelletier

Benjamin Cayden
Benjamin Cayden sidelever repeater.

Part 1

This report covers:

  • The test
  • Adjusting the power
  • DonnyFL Ronin silencer
  • Velocity on high power
  • Velocity on medium power
  • Velocity on low power
  • The trigger
  • Crosman Premiers
  • Shot count
  • Summary

This was a fun test because the Benjamin Cayden gives me lots of things to do. Some, like adjustable power, are things I have dealt with in the past and I’ve figured out good ways to handle them. Others, like the sound of the unmoderated gun firing, are not things I usually deal with. And I have a new sound meter to collect data on that! Let’s get right into the test.

The test

Since the Cayden has adjustable power I thought I would test it with a single pellet and the setting on high, medium and low. That would give us a good idea about the power range as well as the stability at all power ranges. I will also keep track of the reservoir pressure and try to get a shot count, though. as we go. read more


Walther LGR Universal: Part 2

by Tom Gaylord
Writing as B.B. Pelletier

Walther LGR
Walther LGR.

Part 1

History of airguns

This report covers:

  • LGR Universal
  • Velocity RWS R10 Pistol pellets
  • Velocity Gamo Match pellets
  • Velocity RWS Meisterkugeln Rifle
  • What I didn’t tell you
  • Oh phooey!
  • Pumping effort
  • Trigger
  • Summary

Today we look at the velocity and other performance of the Walther LGR Universal rifle. And the first thing to note is I have changed the model name.

LGR Universal

Reader Kevin pointed out that my rifle is an LGR Universal. What distinguishes it as a Universal are several things. The walnut stock was found on the Universal but not on the basic LGR. That one had a beech stock. The walnut Universal stock was also stippled at the pistol grip and on the forearm. The adjustable cheekpiece and buttpad also are only found on the Universal. The performance of both air rifles is the same, the Universal is just an upgraded model. We saw the same thing in the Weihrauch line of match rifles. The HW55 Custom Match was the top model and the HW55 SM was the standard. There is also a rare SF model HW55 that did not have the barrel lock that’s found on all the other HW 55s, but that rifle — a cheapie in its day — is now the rarest HW55 of all! read more


Diana Mauser K98 PCP rifle: Part 2

by Tom Gaylord
Writing as B.B. Pelletier

Diana Mauser
Diana Mauser K98 PCP.

Part 1

This report covers:

  • Fill
  • JSB Exact Jumbo Heavy
  • Fill to 200 bar
  • Discharge sound
  • Discussion 1
  • Beeman Kodiak
  • Pellet feed with the single-shot tray
  • H&N Hollow Point
  • Discussion 2
  • Trigger pull
  • Summary

Today we test the velocity and power of the Diana K98 PCP rifle. According to the description on the Pyramyd Air web page, this is a 26-foot-pound air rifle in the .22 caliber I am testing. This information helps me select the right pellets to test. A pneumatic in this power range is probably best with medium-weight to heavyweight pellets, though I will also test lightweights, just so we know.

Fill

I tried to fill the rifle to 200 bar/2900 psi — the recommended fill pressure, but I waited an instant too long to shut the tank valve and the fill went to 3,000. It’s only 100 psi more. read more


Benjamin Fortitude PCP air rifle Gen2: Part 3

by Tom Gaylord
Writing as B.B. Pelletier

Part 1
Part 2

Fortitude
The Generation II Benjamin Fortitude.

This report covers:

Through the receiver
Man plans…
Power adjust instructions
Testing the rifle  at its lowest power
High power
Adjusting the power down
Air Arms Falcon pellets
How is the air?
What I haven’t told you
Summary

Today we continue the velocity test of the Benjamin Fortitude Generation 2. We are doing this because Crosman has made the Fortitude velocity adjustable by the owner. 

Through the receiver

The Fortitude allows the user to both adjust the velocity as well as depressurizing the rifle in case of an overfill or a need for maintenance. The optional degassing tool fits through the hollow head of the Allen screw that adjusts the velocity, so you use an Allen wrench to adjust power. It’s a regular 3/16-inch Allen wrench, and the head of the bolt that must be turned is near enough to the end of the receiver that the short end of the wrench will work. Both the power adjustment wrench and the degassing tool fit through an opening in the rear of the receiver. The Allen bolt head has been drilled out so the degassing tool will fit through, so don’t be fooled by the looks. read more


Diana 27S: Part 3

by Tom Gaylord
Writing as B.B. Pelletier

Diana 27S
Diana 27S.

Part 1
Part 2

A history of airguns

This report covers:

  • SHOT Show
  • Odd-sized breech seal
  • Grainger
  • Velocity with Air Arms Falcon pellets
  • Fooled around
  • WHAT!!!?
  • On with the test — JSB Exact Heavy
  • Chronograph error
  • Cocking
  • 27S
  • Cocking behavior
  • Firing behavior
  • RWS Hobby
  • Summary

SHOT Show

I’m at the SHOT Show today. Today is Media Day At The Range, so I’m looking at all the new airguns that are on the range in Boulder City. Yesterday I went to Sig Range Day, so tomorrow I will have a report on both events. The show opens on Tuesday, so the Wednesday blog will be my first report from there.

Today we look at the velocity of the Diana 27S we are testing. If you recall, in Part 2 the breech seal failed and I couldn’t test the rifle. I replaced the seal with a temporary leather one and the velocity jumped from the mid-300s to the high 600s. I said then that it was the largest velocity increase I have ever seen from just replacing a breech seal. I expected a gain of 60-80 f.p.s. Several readers made similar comments.

Odd-sized breech seal

When I measured the old seal I expected to find numbers that were even, numbers that made sense! Instead I found the old seal’s material diameter (the thickness of the ring) was 2.4mm. The inside diameter was 8.3mm and the outside diameter was 13.1mm. Okay, where is the camera — I’m on Candid Camera, right? I expected a ring with a thickness of 2.5mm, an ID of 8.5mm and an OD of 13mm. Who would make something common like an o-ring with such random and odd dimensions? The ring wasn’t designed for Diana. Diana selected the ring from what was available and designed their airguns to fit.

Apparently, though, someone did design a ring like this because when I went to Grainger looking for one, there it was — 2.4mm by 8.3mm by 13.1mm! The reason I was so skeptical is because when it comes to measuring things I’m a cut-three-times-measure-once-and-then-hire-somebody-else-to-do-the-job kinda guy. But, listening to all of you guys with skills, I figured I could at least give it a go — might provide some fodder for a funny blog!

Grainger

So I placed an order with Grainger for 25 o-rings. I have about 6-8 Dianas that need these seals, and the way I love these guns more can come at any time. The rings arrived last week, and, with considerable trepidation, I installed one in the 27S. Then I set up the chronograph and fired the first tentative shot.

Diana 27S breech seal
The new o-ring/breech seal from Gainger fit perfectly.

Velocity with Air Arms Falcon pellets

Okay guys, we will start the velocity test with the Air Arms Falcon dome pellet. Ten Falcons averaged 689 f.p.s., for an average muzzle energy of 7.73 foot-pounds. Remember — the magic number of 671 f.p.s. is the velocity at which the energy of the pellet in foot-pounds is equal to the pellet’s weight in grains.

The spread ranged from a low of 672 to a high of 710 f.p.s. That’s 38 f.p.s., which is high.

Fooled around

After that I shot some more Falcons and got a string of three that measured 320, 309 and 310 f.p.s. — WHAT!!!?

WHAT!!!?

Right after installing the new breech seal and shooting the gun at velocities in the 690s, I suddenly got one at 374 f.p.s. And that is when it hit me. The new breech seal DOES NOT add 300 f.p.s. to the velocity of the rifle! I had shot through the chronograph in such a way that the first skyscreen was triggered at the wrong time. I know that because I can now do it anytime I want.

It isn’t common but I have seen this phenomenon before. If the muzzle of the gun is too close to the first skyscreen (with Shooting Chrony chronographs) you will get a reading like this. In the case of this Diana 27S I also have to point the barrel slightly downward by a few inches at 3 feet to make it happen every time. That is what happened in the last test, but I didn’t catch it until today. It was just the way I was sitting that made it happen. Apparently the Diana 27S is just long enough to put the muzzle in the exact right spot for this to happen.

So — chronograph users beware. And everybody — a new breech seal should not increase velocity by 300 f.p.s. unless there was no seal to begin with!

On with the test — JSB Exact Heavy read more


Air Arms Pro-Sport: Part 7

by Tom Gaylord
Writing as B.B. Pelletier

Pro-Sport
Air Arms Pro-Sport.

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

This report covers:

  • Disassembly
  • Rotate forward spring guide
  • The washers
  • Factory top hat
  • Last note
  • Assembly
  • Relubed
  • Gun back together
  • Velocity with RWS Hobbys
  • Velocity with Baracuda 5.50mm heads
  • Cocking effort
  • The question
  • Summary

Today we look at the Air Arms Pro-Sport with the Vortek PG3 tune kit installed at its most powerful setting. This test was suggested by reader Yogi in the comments to Part 5.

“To finish up the review, how about exploring the other 2 notches in the PG3 kit? Maybe one notch is full OEM power, second notch is the desired 12 foot-pounds, and the third one(the one you have it set on) is good for 10.5 foot-pounds.

This way you have a full report on the Pro-Sport AND the PG3 kit.”

I though that was a great idea. Unless I test it, who knows what the other notches will do? And also there are the two heavy washers that add weight to the piston and more tension to the mainspring.

What I won’t do is test every possible combination of the kit. Besides the three notches there are two washers, so that’s a possible 9 different combinations to test — low notch no washers, low notch one washer, low notch 2 washers, mid notch no washers etc.

Instead, I will go to the opposite end of possibilities and set the mainspring on the high notch with two washers installed. That will bracket the power possibilities.

Disassembly

The Pro-Sport came apart in a few minutes with no mainspring compressor needed. Remember that with this Vortek kit the pretension on the mainspring is even less than on the factory gun and even that doesn’t need a compressor.

Pro-Sport Vortek kit
The thousand-word picture. The mainspring is in the lowest notch from the previous tune. The two washers from the Vortek kit are going in ahead of the forward spring guide (black thing the mainspring is wound around) that’s inside the piston. The factory top hat is shown below. One of the washers is stuck to the tip of a magnet to show that it’s ferrous.

Rotate forward spring guide

To get the end of the mainspring into the highest notch in the base of the forward spring guide, the spring guide has to be rotated. However, the inside diameter of the relaxed spring is smaller than the outside diameter of the spring guide — so the spring is on the guide extremely tight. It look me 20 minutes of fiddling with a screwdriver to move the guide high enough to make the slight rotation that was needed. You don’t want to grab the base of the guide with pliers because it is synthetic!

After that was accomplished the rest of the job took mere minutes. But before I go there, let’s look at what I’m about to do.

The last tune was with the spring set in the lowest notch of the spring guide. And no washers were used. So the piston was almost as light as it could be. By removing the synthetic spring guide it would have been a few grains lighter, but the spring would then have had room to vibrate on the piston stem. Vibration is a bad thing, so those few grains of weight are well spent.

The washers

I weighed the two washers, which are steel. One weighed 85.5 grains and the other weighs 86.2 grains. When I add that the two should weigh 171.7, but for some reason my scale says 171.4 grains. We are talking about a weight difference of a postage stamp, so it may be more in the technique I was using to place them on the scale than any real weight difference. At any rate, an additional 171.4-grains of weight is being added to the Pro-Sport piston.

Pro-Sport Vortek washers
Both Vortek washers together weigh 171.4 grains. They will be going into the piston ahead of the mainspring.

Factory top hat

For curiosity I also weighed the factory top hat that goes into the piston like the washers. It weighs 352.2 grains, or 180.8 grains more than the two washers. It’s a little over twice the weight of the two washers. That’s interesting but I don’t know why.

Pro-Sport top hat
The factory steel top hat weighs 352.2 grains.

Last note

If someone reads this entire report they will discover that I removed the sliding compression chamber for the first tune in Part 5. I did it because the piston didn’t want to go into the chamber when I started assembling the gun. But it really isn’t necessary to do that. Just fiddle with the piston and the piston seal will eventually clear and go in the chamber. This time I did not remove the sliding chamber and the time to assemble was cut by several minutes.

Assembly

I won’t show you the entire assembly of the rifle because that was covered pretty well in Part 5. I will just show you the order of the parts as they go back into the gun. The two washers go onto the piston rod first. They add that 171-grains of additional weight to the piston, which should change its performance with heavier pellets a little. They also add perhaps a quarter-inch or a little more of preload to the mainspring.

The higher notch on the spring guide also adds a little preload to the spring. I would guess that together the notches and the two washers add about 3/8-inch of preload. That isn’t much, so Yogi, I doubt we are going to see the factory spec with this kit. I think it may get a little closer to 12 foot-pounds, which is what the specs tell us to expect.

Pro-Sport notch
There is the end of the spring in the highest notch. It isn’t seated all the way but when I cock the rifle it will seat. read more


Diana 27S: Part 2

by Tom Gaylord
Writing as B.B. Pelletier

Diana 27S
Diana 27S.

Part 1

A history of airguns

This report covers:

  • Velocity day
  • A happy accident
  • Breech seal
  • No problemo!
  • BB isn’t daunted
  • Problemo
  • BB has a backup
  • HOWEVER
  • What size are the seals?
  • What now?
  • Cocking effort
  • Trigger pull
  • Today’s report
  • Summary
  • read more