Diana 23: Part 1

by Tom Gaylord
Writing as B.B. Pelletier

Dioana 23
Diana 23.

A history of airguns

This report covers:

  • A stripper
  • The rifle
  • Two versions of the later rifle
  • Trigger
  • Breech seal and locking detent
  • Sights
  • Cocking
  • What is it good for?
  • Summary

This report should be titled, “By any other name” because the airgun I’m writing about doesn’t say Diana anywhere. It says Gecado, Mod. 23. I know it is a Diana because I have paid attention to Diana air rifles for the past four decades, or so. They can also be named Hy Score, Winchester, Peerless, Original, Milbro, RWS, Geco (of which Gecado is a derivative) and Beeman. And I bet there are more names I haven’t mentioned.

Dioana 23 markings
These are the principal markings on the rifle. There is no serial number, caliber or date of manufacture.

A stripper

Decades ago a new car that was basic and was priced as low as that model would go was called a stripper. Well, the Diana 23 is the stripper of Diana pellet rifles. In the photograph above the rifle appears to be the same size as a Diana 27, but when you see them together the difference becomes obvious. 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


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 Swarm Fusion 10X Gen II air rifle: Part 3

    by Tom Gaylord
    Writing as B.B. Pelletier

    Gamo Swarm Fusion
    Gamo Swarm Fusion 10X repeating rifle.

    Part 1
    Part 2

    This report covers:

    • Today’s test
    • The test
    • Trigger adjustment
    • Sight-in
    • Air Arms Falcon
    • H&N Match Green
    • Gamo Master Point
    • RWS R10 Pistol
    • Firing behavior
    • JSB Exact 8.44-grain domes
    • H&N Baracuda Green
    • JSB Exact Heavy
    • JSB Exact RS
    • Firing behavior
    • Whew!
    • 10-shot group with Match Green
    • Conclusion?
    • Summary

    Today we start looking at the accuracy of the Gamo Swarm Fusion 10X Gen II repeating breakbarrel spring-piston air rifle. I’m hoping for a great result!

    Today’s test

    The Swarm Fusion has open sights, and I’m testing them today. It also comes bundled with a scope that I will test in another report. Since this is the first accuracy test, I decided to just shoot 5-shot groups so I could test lots of different pellets. Let’s get started.

    The test

    I shot off a sandbag rest at 10 meters. I used a modified artillery hold, because the thumbhole stock on this rifle doesn’t permit a classic hold. The only difference is I did grasp the pistol grip.

    I rested the rifle on the flat of my open palm with the heel of my hand back by the triggerguard. A rifle that recoils like this cannot rest directly on a bag or anything else!

    I made no attempt to adjust the sights throughout the test until the very end. So, after sight-in the pellets went where they wanted to.

    Trigger adjustment

    I told you in Part 2 that I would buy a long-bladed small Phillips screwdriver to adjust the stage two trigger pull. After I had placed the order, reader New To Old Guns told me the second stage is already adjusted as short as it can be. Nevertheless, when the screwdriver arrived I tried adjusting it.

    Gamo Swarm Fusion trigger
    Don’t bother trying to adjust the second stage of the trigger. I did and there was no change.

    NTOG was right, there isn’t anything you can do to the second stage. I adjusted it several times and found no difference. Well, at least I now own a nice set of long-bladed screwdrivers!

    Sight-in

    Since I was shooting with the installed open sights I started shooting at 10 meters. The first shot went high and I discovered the rear sight was adjusted up quite far. That was something I’m sure I did when examining the rifle. I adjusted it down and was on target in three shots.

    Air Arms Falcon

    The first pellet was the Air Arms Falcon. Four went into a tight 0.245-inches, but the fifth pellet opened it to 0.656-inches between centers at 10 meters. Maybe this pellet is worth further exploration.

    Swarm Fusion Falcon group
    Air Arms Falcons were tantalizing. Four are in 0.245-inches, but the fifth shot opened it to 0.656-inches at 10 meters.

    H&N Match Green

    Next up were H&N Match Green pellets. Every one of the five shots broke the sound barrier with a loud crack. But they were accurate! Five made a group that measures 0.341-inches between centers.

    Swarm Fusion Match Green group
    The Swarm Fusion sent 5 H&N Match Green pellets into a 0.341-inch group at 10 meters. read more


    Diana 27S: Part 1

    by Tom Gaylord
    Writing as B.B. Pelletier

    Diana 27S
    Diana 27S.

    A history of airguns

    This report covers:

    • Carel
    • Diana 27S
    • Anti-beartrap
    • Description
    • Dimensions
    • Sights
    • Ball bearing sear
    • History
    • Parts interchange
    • Summary

    This report is one I wanted to write months ago, but after all I wrote about reader Michael’s Winchester 427 and my own Diana 26 and Diana 35, I thought I had better let vintage Dianas rest for awhile.

    Carel

    I purchased this Diana 27S along with the Diana 26 and Diana 35 I have just mentioned from reader Carel of the Netherlands. He gave me a fantastic deal on three air rifles that are quite uncommon in the US. The 35 is the most common of the three, but Carel had a very early one that was different than the one many Americans have seen, so it was just as uncommon to me as the other two.

    Diana 35
    The Diana 35 I got from Carel is a very early one that we don’t often see in the U.S.

    I was able to tune the 35 to be a smooth shooter and an easy cocker — something that you don’t see with run-of-the-mill Diana 35s (and Winchester 435s/Hy-Score 809s/Beeman 200s that are all the same rebranded models). That was a 6-part series that’s linked above.

    Diana 27S

    And now we come to the subject air rifle — the .177-caliber Diana 27S. What is it? Well, there is very little written about this model so I’m going to expand your horizon just a tad. There are some subtle refinements on this scarce Diana model.

    In the UK the German Diana is called the Original Diana, because the Milbro company of Scotland received the rights to produce and sell Diana airguns as war reparations following WWII. In the 1981 edition of The Airgun Book, author John Walter says the Original Diana 27S comes with “an automatic trigger-blocking safety”. I thought, “Oh, no — not one of those!” But don’t fret. He didn’t mean what you think.

    Anti-beartrap

    What Walter meant was the 27S has an anti-beartrap device built into it, unlike the standard model 27 that you can close when it’s broken open by pulling the trigger (restrain the barrel when doing this!). There is no separate safety lever on the 27S. But the barrel has to be closed in order for the trigger to work, so Walter is correct in what he says, but the term anti-beartrap is used more commonly for this feature today. We will take a closer look at the parts that support this function when we go inside the rifle. Yes, we will be going inside!

    Description

    The Diana 27S is a conventional breakbarrel spring-piston air rifle, but it differs from the 27 in a couple obvious ways. The triggerguard is very angular The forearm is also squared off and the end is cut on an angle instead of being rounded like the forearm end of a standard 27. The butt has a thin rubber pad that’s separated from the wood by a white line spacer. On a conventional model 27 there is just a red rubber button at the top of the wooden butt to help the rifle stand on its butt without slipping.

    Diana 27S logo
    The Diana logo shows Diana dropping her bow for a rifle. As you can see, there are flecks of rust in the blue. Ballistol and 0000 steel wool will handle them.

    Diana 27S butt pad
    The 27S has a whole butt pad, where the 27 just has a rubber button.

    My .177-caliber 27S rifle weighs 6 pounds 10 oz., which is one pound one ounce heavier than my .22-caliber Diana 27 (Hy-Score 807). The .177 caliber adds a little weight because the barrel, having thicker walls, weighs a little more. Also the forearm of the stock is a trifle wider and the cocking slot is shorter because the two-piece cocking link is articulated and therefore doesn’t need the longer slot. More wood means more weight. In theory this makes the stock stiffer, which should help to reduce vibration a little, but in this day of

    Tune in a Tube read more


    What does the new year hold?

    by Tom Gaylord
    Writing as B.B. Pelletier

    This report covers:

  • What the new year holds
  • Big bores
  • High-tech projectiles
  • Price point PCPs (PPP)
  • Basic features of a PPP
  • Things that are good to have
  • Kiss of death for a PPP
  • Horsepower wars over?
  • Optics
  • Electronics in scopes
  • Scope mounts
  • Air compressors
  • Replica airguns
  • A dual-power spring-piston breakbarrel
  • M16 replica
  • M1 Garand replica
  • Summary
  • 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