Tuning Michael’s Winchester 427: Part 8

by Tom Gaylord
Writing as B.B. Pelletier

Diana 27
Michael’s Winchester 427 is a Diana model 27 by another name. The rifle pictured is my Hy Score 807/Diana 27.

Part 1
Part 2
Part 3
Part 4
Part 5
Part 6
Part 7

A history of airguns

This report covers:

  • Recap
  • Tune in a Tube
  • But the rear sight…
  • The rifle is fixed!
  • Breech seal shim
  • Pivot bolt locking screw
  • Accuracy
  • Air Arms Falcons
  • RWS Hobby
  • Then I read…
  • Michael’s rifle is accurate
  • The big surprise!
  • Next

Today was a long time coming — much longer than I anticipated. But I learned a lot about problems with the Diana 27 that I have never encountered before, and I now believe I can tune one with ease.

Recap

Just so you remember, I am tuning reader Michael’s Winchester 427 that is a Diana 27 by another name. It looked good on the outside, apart from missing things like the rubber button on the butt and a locking screw for the pivot bolt. The rear sight was a kluge of backwoods “repairs”, but that didn’t impress me until the very end of the job. In fact, I will tell you now that I should have started there first. It was the main source of the rifle’s issues. read more


Tuning Michael’s Winchester 427: Part 7

by Tom Gaylord
Writing as B.B. Pelletier

Diana 27
Michael’s Winchester 427 is a Diana model 27 by another name. The rifle pictured is my Hy Score 807/Diana 27.

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

A history of airguns

This report covers:

  • New breech seal
  • The breech test
  • Second tune with a new piston seal
  • The hand test
  • No relief
  • Rear sight was fooled with
  • Too much air escapes the compression chamber
  • Where we are
  • Summary

This is the report about tuning reader Michael’s Winchester 427, which we know is a Diana 27. It’s a .22 caliber breakbarrel air rifle.

New breech seal

I completed the tune in Part 6 and then started shooting the rifle to burn off the excess oil from the piston seal pre-lube. I expected one or two explosions after the tune, but the rifle never stopped detonating. It was constant. Something was wrong.

The breech test

The rifle acted like it was leaking air at the breech. There is a way to determine whether the breech seal leaks. Put something light, like tissue paper, over the breech and see if it gets blown off by escaping air. I did that and the paper stayed in place when the rifle fired. So the breech seemed to be okay. read more


Tuning Michael’s Winchester 427: Part 6

by Tom Gaylord
Writing as B.B. Pelletier

Diana 27
Michael’s Winchester 427 is a Diana model 27 by another name. The rifle pictured is my Hy Score 807/Diana 27.

Part 1
Part 2
Part 3
Part 4
Part 5

A history of airguns

This report covers:

  • Assembling the ball bearing cages
  • Two cages — inner and outer
  • The real sear
  • Trigger assembly
  • Finish the assembly
  • Trigger adjustment
  • Test the rifle
  • Summary

And I’m going to pick it up right where we left off on Friday. A reminder that I am in Las Vegas at the SHOT Show today and will not be able to respond to comments as easily as normal. Let’s get started.

Assembling the ball bearing cages

We have come to the most daunting part of the assembly — assembling the trigger unit. You have to put a swarm of loose parts into the spring tube under tension from both the mainspring and the trigger spring. First, put the lubricated spring guide into the rear of the mainspring. I forgot to do that the first time through and I assembled the rifle without the guide. Got the rifle all buttoned up and said those famous last words, “I hope I never have to do THAT again!” Then my eyes fell on the guide sitting on the table. It was smiling at me, and I’m pretty sure I heard God laugh a little! read more


Tuning Michael’s Winchester 427: Part 4

by Tom Gaylord
Writing as B.B. Pelletier

Diana 27
Michael’s Winchester 427 is a Diana model 27 by another name. The rifle pictured is my Hy Score 807/Diana 27

Part 1
Part 2
Part 3

A history of airguns

This report covers:

  • Reader MarklinJHawkland
  • The blind pin
  • Sheared the screw
  • The lesson
  • Cleaning the spring tube
  • Other cleaning
  • The assembly
  • Summary

I’m tuning and overhauling reader Michael’s .22 caliber Diana 27, which is actually a Winchester 427. In Part one I disassembled it and in Part two I showed you how the ball bearing trigger works. In Part three I talked about removing the old piston seal that had a screw that was stuck. I have a lot more to say about that today.

Reader MarklinJHawkland
This is the reader who solved the puzzle. I knew there is a pin in the head of the piston, because when I disassembled the rifle someone had tapped that pin in far enough for me to see it. Unfortunately it was probably that and not the rust that had jammed the screw in place. read more


Tuning Michael’s Winchester 427: Part 2

by Tom Gaylord
Writing as B.B. Pelletier

Diana 27
Michael’s Winchester 427 is a Diana model 27 by another name. The rifle pictured is my Hy Score 807/Diana 27.

Part 1

A history of airguns

This report covers:

  • How can a ball be a sear?
  • Three balls instead of just one
  • How the trigger works
  • Seen it before
  • Discussion
  • Summary
  • Last word

Today I’m going to try to explain how the Diana ball bearing trigger works. This is a design that seems complex, but once you understand it you understand a lot about how the Diana 27 goes together.

How can a ball be a sear?

A ball can restrain something from moving by blocking it. When the ball moves out of the way, the item that was restrained is free to move. Let me show you.

ball sear 1
In this view, the ball blocks the large bar (which represents the piston) that is being pushed by the force from a spring. As long as the ball doesn’t move, the shaded bar/piston cannot advance. The ball cannot move because there is another bar restraining it on top. read more


Diana model 30 gallery gun: Part 2

by Tom Gaylord
Writing as B.B. Pelletier

Diana model 30 gallery gun
Diana model 30 gallery gun.

Part 1

A history of airguns

This report covers:

  • Cocks hard!
  • Description
  • Trigger
  • Safety
  • Sights
  • Potential accuracy
  • Why was this airgun so hard to get in the U.S.?
  • The end — or maybe not!

You’ve had a weekend to contemplate this gallery gun and today I will finish describing it and talking about its basics.

Cocks hard!

All of these bolt-action repeaters cock really hard, and the Diana model 30 is no exception. The piston can only move a short distance, so the mainspring has to be stiff enough to give the ball a good push. Even so I wouldn’t look for much velocity. My experience with a Haenel 310 tells me this one will shoot 350 f.p.s. or less. We will see in the next report and I will also measure the cocking effort.

Description

The rifle is 42-3/4-inches long, overall. The barrel is 16.9-inches of that. The pull measures 13-1/2 inches. The rifle weighs 7 lbs. 6 oz. read more


Diana model 30 gallery gun: Part 1

by Tom Gaylord
Writing as B.B. Pelletier

Diana model 30 gallery gun
Diana model 30 gallery gun.

A history of airguns

This report covers:

  • Description
  • Caliber 4.4mm
  • The fix
  • Power was intermittent
  • Rifled
  • Discussion
  • Summary

Apparently there have been three Dianas model 30. Blue Book of Airguns calls them out and tells us the differences. Last week there was some confusion about which Diana model 30 airgun I was referring to in a comment, and when I clarified it one of our readers asked for a report. It happened that I then visited a friend who has a model 30 gallery gun, and he told me it wasn’t working. I said I would try to get it working again if I could test it for the blog, so here we go.

Description

The Diana model 30 gallery gun is a spring-piston rifle that uses a bolt to cock the mainspring. It’s similar in function to a great many other bolt-action airguns like the Schmeisser model 33, the Anschütz model 275, the Haenel model 310 that copies the Anschütz, and even the Czech models VZ35 and VZ48. All of those airguns are rifles like this one, but if we expand the list to include smoothbores we have to acknowledge the Mars models 85, 100 and 115. There are probably others I haven’t mentioned. read more