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


Webley Service Mark II: Part 7

by Tom Gaylord
Writing as B.B. Pelletier

Webley Mark II Service rifle
Webley Mark II Service Rifle.

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

A history of airguns

Today’s report is another in the series I did on the Webley Mark II Service rifle. Today’s post is by reader RidgeRunner, who now owns the rifle. He tells us about his rifle’s performance after the maintenance he reported in Part 6.

If you’d like to write a guest post for this blog, please email me.

And now, take it away, RidgeRunner.

This report covers:

  • A Round Tuit
  • My Chrony Rig
  • Into The Breech!
  • RWS Super H-Point
  • Eley Wasp
  • H&N Sniper Light
  • H&N Field Target
  • JSB Exact Jumbo RS
  • JSB Exact Jumbo
  • Crosman Premier Hollow Point
  • H&N Baracuda Hunter Extreme
  • H&N Baracuda
  • Summary

A Round Tuit

round tuit

Well, it took me a while to get to this, but now that I have a round tuit I can start doing the velocity test on this old gal. Since I spent most of a warm, calm, sunny Sunday shooting this air rifle, you might want to make sure you have a full cup of coffee before you go much further. read more


Crosman’s Mark I Target pistol: Part 2

by Tom Gaylord
Writing as B.B. Pelletier

Crosman Mark I
Crosman Mark I target pistol.

Part 1

A history of airguns

This report covers:

  • Loading the CO2 cartridge
  • O-ring material
  • Velocity
  • RWS Hobby
  • Air Arms Falcons
  • Crosman Premiers
  • Discussion
  • Shot count
  • Trigger pull
  • Summary

Today we look at the power of my Crosman Mark I Target pistol. This will be interesting because I don’t remember ever doing it. I probably did, but without a report to read I can’t remember.

Loading the CO2 cartridge

Usually on a CO2 pistol that stores the 12-gram CO2 cartridge in the grip, one of the grip panels comes off to remove and install the cartridge — the left one, more often than not. Not so with this pistol. Instead there is a large knurled cap at the bottom of the grip that is removed, and the cartridge inside slides out. If there is still significant gas in the gun, the pressure will force the o-ring in the cap to seal the cap tight and it may not rotate. Don’t use pliers to force it! Shoot the gun until the gas is gone or almost gone. read more


Crosman’s Mark I Target pistol: Part 1

by Tom Gaylord
Writing as B.B. Pelletier

Crosman Mark I
Crosman Mark I target pistol.

A history of airguns

This report covers:

  • History
  • Mark II
  • The pistol
  • Two power levels
  • Grips
  • Sights
  • The trigger
  • Power
  • The pinnacle of its time
  • Ergonomics
  • Modified guns
  • How long do they hold?
  • Summary

I wanted to write about the Crosman Mark I target pistol today, but was afraid I might have reported on it too many times in the recent past. However, when I looked, I discovered that I have never fully tested this airgun for you! I wrote about it back in 2005 and re-ran that report in July of 2015, but apparently I’ve never gone all the way and done a complete test. That ends today.

History

The .22 caliber Mark I Target pistols were made by Crosman from 1966 to 1983. In 1980 Crosman removed the power adjustment capability from the gun, so those made from ’66 to ’80 are called the first variation, while those made from ’80 to ’83 without power adjustment are called the second variation. The first variation guns are considered more desirable, only because of the additional feature of power adjustment. read more


Tuning Michael’s Winchester 427: Part 3

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

A history of airguns

This report covers:

  • The piston seal
  • Tractors
  • Hierarchy of removing a stuck piston seal screw
  • Time to move on
  • Remove rust
  • What’s next?
  • Have to make a breech seal
  • How to make the seal
  • Summary

This is a continuation of the report on overhauling reader Michael’s Winchester 427 that is a Diana 27. Today I’m showing you the details of working on a spring gun.

The piston seal

When Diana chose a threaded screw to attach the piston seal to the piston body, they couldn’t have selected a worse method of fastening. A screw was a common way to attach spring-gun piston seals in the 1950s and ’60s, but it wasn’t a good way, because over time the screw threads corrode and cement the screw in place. In the case of Michael’s rifle, the corrosion is particularly bad, so that screw wants to stay put. 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


Tuning Michael’s Winchester 427: Part 1

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

A history of airguns

This report covers:

  • Michael’s Diana 27
  • Out of the box
  • Flat breech seal
  • No baseline test
  • Onward Through The Fog
  • Remove the action from the stock
  • Action into the compressor
  • Remove the piston
  • Disassembly complete
  • List of jobs
  • Summary

Michael’s Diana 27

Some time back, reader Michael mentioned some problems he was having with his new/old Winchester 427, which is a Diana 27 by another name. I offered to tune it for him because it’s been some time since I have been inside a 27. There are many new readers who are not aware of this wonderful air rifle, and I thought it was time they learned about it.

Diana made the model 27 for a great many years after WW II, and they made them for a number of other companies, as well. The guns were made in both .177 and .22, but Winchester and Hy Score only ordered them in .22 caliber, so a 427 and an 807 are always .22. read more