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


    Gamo 126 single stroke pneumatic 10-meter target rifle: Part 2

     

    by Tom Gaylord
    Writing as B.B. Pelletier

    Gamo 126
    Gamo 126 single stroke pneumatic 10-meter target rifle.

    Part 1

    A history of airguns

    This report covers:

    • RWS Basic
    • Sig Match Ballistic Alloy
    • RWS R10
    • Warmed up?
    • Second string of RWS Basics
    • Pump effort
    • Trigger pull
    • Discussion
    • Summary

    Today is velocity day for the Gamo 126 target rifle we are testing. We learned a lot from the comments in Part 1 and I also learned a lot while researching the rifle for this report. Today we will see where this particular one is.

    The Blue Book of Airguns said to expect a velocity of 590 f.p.s., but many owners say 550 is about as fast as they ever shoot and some even say less. The rifle also starts loosing velocity over time, so we should be able to assess the health of the gun I am testing right away.

    RWS Basic

    I will start with the lightest lead wadcutter anyone is likely to use — the 7-grain RWS Basic. I will warm up the action with several shots before starting to chronograph the results.

    The first string of Basics averaged 434 f.p.s. The low was 415 and the high was 449 f.p.s. The spread from low to high was 34 f.p.s. I guess this 126 is getting tired again, following its reseal.

    Sig Match Ballistic Alloy

    Next to be tested were Sig Match Ballstic Alloy pellets They weigh 5.25-grains and should be the fastest that I test today. Ten of them averaged 496 f.p.s. The spread went from a low of 490 to a high of 501 f.p.s. That’s 11 f.p.s., so this pellet might be accurate. And the rifle may be warming up, so I need to test Basics again.

    RWS R10

    The next pellet I tested was the 7-grain RWS R10 Match Pistol pellet. I also tried a different way of pumping the gun. Instead of forcing the pump lever closed as fast as possible I went with a smooth motion that was decidedly slower. R10s averaged 454 f.p.s. with a spread that went from 449 to 460 f.p.s. That’s an 11 f.p.s. spread.

    Warmed up?

    It seemed like two things had happened as I shot this test. First, the rifle’s pneumatic mechanism had warmed up and second, the different way of pumping seemed to have given the shots more stability. So I wanted to try RWS Basics once more.

    Second string of RWS Basics

    This time 10 RWS Basics averaged 452 f.p.s. That’s faster than the fastest pellet in the first string (449 f.p.s.). So one or both of the things I said were working. The spread for this string went from a low of 432 to a high of 462 f.p.s., so a difference of 30 f.p.s. That is close to the 34 f.p.s. I got in the first string, so I think this Basic pellet is just not that stable in this rifle. But the rifle pump mechanism definitely did warm up a little!

    Pump effort

    The Gamo 126 and Walther LGR 10-meter target rifles both share a common flaw, in that their pump stroke is on the closing stroke when their levers move forward. This tends to make both rifles harder to pump than other single-strokes, though the Gamo has some kind of pump assist in its oil-filled piston and is actually easier to pump than any other 10 meter single stroke rifle.

    The rifle I am testing requires 15 pounds of force to pump if you go steady and smooth. If you force the lever the effort spikes to more than 20 pounds. Only the awkward placement of the pump fulcrum at the rear of the action gives any hinderance at all.

    Trigger pull

    Now we come to the thing I am most interested in — the trigger pull. I told you in Part one that the 126 has a world-class trigger and now we will see how correct that was.

    This is a two-stage trigger as all target triggers should be. I mean real target triggers — not just triggers that have the name target in their title. Stage one takes 3 ounces to complete and stage two breaks at 3.4 ounces. That’s an average of 5 pulls.

    Discussion

    The powerplant in my rifle is not performing to spec. But it is fairly stable if I pump it correctly. I can live with that long enough to get through the accuracy test that comes next.

    Summary

    It seems that reader Geezer was right about the Gamo 126. It apparently does have performance issues. I always heard that it did, but now I know what they are and why they exist.

    Does a 126 belong in a collection of vintage 10-meter target rifles? At this point I think it does — warts and all. But I still need to see the accuracy to know for sure.


    Air Arms Pro-Sport: Part 5

    by Tom Gaylord
    Writing as B.B. Pelletier

    Pro-Sport
    Air Arms Pro-Sport.

    Part 1
    Part 2
    Part 3
    Part 4

    This report covers:

    • The inspiration
    • The kit
    • Installing this kit
    • Disassembly
    • Examine the parts
    • Factory top hat
    • Install the PG3 mainspring/li>
    • Spring guides very tight!
    • Assemble the piston and spring
    • Compression chamber is buttoned
    • Finished assembly
    • Discussion
    • Cocking effort
    • Firing behavior
    • Velocity with Hobbys
    • Additional benefit
    • Velocity with H&N Baracuda
    • Summary

    Today is the day, airgunners. This is the day we open the .22-caliber Air Arms Pro-Sport we are testing and install a Vortek PG3 tune kit. It’s a drop in one-for-one replacement powerplant kit that promises to lower the cocking effort of the rifle and smooth out the shot cycle. The power output is 12 foot-pounds in .22 caliber which would be a 11.9-grain RWS Hobby leaving the muzzle at 674 f.p.s. And someone says, “Gee, BB, don’t you know you’re not supposed to tune for LESS velocity?”

    Yes, I do. And this is exactly what I want. Even if I only get 625 f.p.s. with the Hobbys it’s what I want. Because I’m going for smooth — not power.

    The inspiration

    The initial inspiration was a Venom Mach II rifle that was owned by Trooper Walsh. That was the rifle that the Pro-Sport was built to copy, and it was a sheer delight to cock and fire. However, at $2,000 in the 1990s, it was an airgun I could never afford to own.

    Then a few months ago I happened to shoot Jeff Cloud’s Pro-Sport. Once again it was a sheer delight to cock and shoot. It reminded me of the Mach II of my past. Only this rifle is still being produced, and at a far more affordable price. And Vortek makes the spring kit that tames the beast,

    The kit

    The kit consists of a new mainspring, a spring guide, a “top hat” that is a forward spring guide living inside the piston, two spacer washers, a small tub of grease and instructions.

    Pro-Sport PG3 kit
    The PG3 kit consists of a new mainspring, a white spring guide, a black “top hat” forward spring guide for inside the piston, two washers that can be used as spacers to increase the preload of the mainspring , a small (but way more than adequate) tub of grease and the instructions.

    The instructions tell how to install the kit. There are several options that can be applied, and the instructions address them. They do not tell you how to disassemble the rifle.

    Installing this kit

    I found this kit very easy to install, but before you jump in with both feet, remember that I have been doing things like this for decades. What seems easy to me may not seem that easy to you. I do find Air Arms spring guns easier to work on than any other brand for several reasons. First, they are so well made that you seldom if ever encounter a problem from the manufacturer. Second, neither the TX200 Mark III nor the Pro-Sport require a mainspring compressor to safely open the powerplant.

    I had never opened a Pro-Sport before this day, so what you are about to see was as new to me as it will be to many of you. But the Pro-Sport only differs from the TX200 in a few small ways that aren’t a hindrance, and I know TXs very well.

    Disassembly

    First remove the barreled action from the stock. This is straightforward, except that both of the triggerguard screws need to be removed and the triggerguard with them. Both screws are attached to the barreled action. The rear one attaches to the rear of the trigger unit.

    To get the action out of the stock the underlever needs to be opened (not cocked — just pulled away from the barrel) to slip out of the cocking slot of the stock. Once the action is out you can open it by unscrewing one bolt. It’s the bolt that the front triggerguard screw attaches to. It has an 11mm head and comes right out, but here is a tip. If you want to find out how much preload the mainspring is under you can press the back of the end cap on the action against a padded place on your bench while unscrewing the bolt by hand (once it’s loose). The pressure you have to press the action down with to make this bolt loose enough to turn by hand is the amount of preload the spring is under. The factory mainspring took about 40 pounds of downward pressure to turn the bolt.

    Pro-Sport bolt out
    When the bolt is removed the trigger comes out. It’s pushed by the mainspring, and this is as far as it goes. This is why a compressor is not needed.

    Slide the trigger out of the gun and then slide out the mainspring and spring guide, followed by the piston. Because the Pro-Sport has a sliding compression chamber, the piston is not held in the gun at this point. If it doesn’t slide right out it may help to pull the underlever down smartly and the piston should come sliding out.

    Pro-Sport mainspring and piston
    The trigger slides out and so does the mainspring and piston.

    Examine the parts

    I looked at the parts at this point. I expected to see perfectly machined and finished parts because this is an Air Arms airgun. I was not disappointed. The spring was lubricated with their grease in what looked like the correct amount. Their grease is thinner than the Tune-In-A-Tube I plan to use, so a lot of vibration should disappear when I install and lube the new spring.

    Pro-Sport mainspring lube
    Air Arms lubed the mainspring perfectly. But their grease is thinner than TIAT.

    Factory top hat

    A top hat is a forward spring guide that lives inside the piston. It is engineered to take up all the slack in the inner diameter of the mainspring, so it doesn’t vibrate on the piston rod when the gun shoots. It can also add significant weight to the piston, which makes the gun more efficient with heavier pellets. I could see a top hat inside the piston by shining a bright flashlight inside.

    The Vortek kit comes with its own top hat, so the factory part must be removed. It didn’t just slide out, so I used a 4 by 4 wooden post and whacked the rod end of the piston down on the post to jar it loose. One rap was all it took.

    Pro-Sport top hat
    One whack of the end of the rod against a post was all it took to get the top hat (left) out of the piston. read more


    Gamo Swarm Fusion 10X Gen II air rifle: Part 2

    by Tom Gaylord
    Writing as B.B. Pelletier

    Gamo Swarm Fusion
    Gamo Swarm Fusion 10X Gen II rifle.

    Part 1

    This report covers:

  • Well!
  • Another breakbarrel repeater
  • Easy loading
  • High velocity
  • Gamo Platinum PBA
  • Cocking is easy
  • Trigger adjustment
  • Trigger pull
  • RWS Hobby
  • RWS Superdome
  • H&N Baracuda Magnums
  • Gamo Platinum PBA — again
  • Pellet feeding
  • Summary
  • read more