Category Archives: maintenance

maintenance category

The Diana model 50 underlever: Part 6

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by Tom Gaylord
Writing as B.B. Pelletier

Diana 50
Diana model 50 underlever.

Part 1
Part 2
Part 3
Part 4
Part 5

A history of airguns

This report covers:

  • The test
  • Sight in
  • RWS Superdomes
  • The trigger
  • RWS Supermags
  • Feel of firing|
  • RWS Hobbys
  • Why shoot only RWS pellets?
  • H&N Baracuda 4.50 mm head
  • Discussion
  • Summary

Today I shoot the Diana model 50 underlever with sporting sights from 25 yards. Let’s see what she’ll do!

The test

I shot indoors from 25 yards off a sandbag rest. I used the artillery hold with the rifle rested on my off hand, about 8-9 inches forward of the triggerguard. The Diana 50 is an underlever, and that steel cocking mechanism makes it heavy up front, so this is the most comfortable way to stabilize it. I shot 10-shot groups at 10-meter pistol targets. 

Sight in

Because I moved the rear sight forward for this test, I had to sight in the rifle again. The first shot was from 12 feet and impacted at the top of my front sight, so I called it good and backed up to 25 yards. I knew the shots would hit higher from back there, but since the first shot hit at 6 o’clock on the bull and this was a pistol target, I reckoned there was plenty of room. read more

Beeman P17 valve modification: Part 6

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by Tom Gaylord
Writing as B.B. Pelletier

Today’s report is a guest blog from reader Streetmusician. As far as I can remember he has never signed into the blog under that name, but that is his handle. He tells us how he got more velocity out of his Beeman P17.

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

This report is an important part of the Beeman P17 series, so I am linking it to the other reports we have done on the pistol. The first two parts tell you how to reseal the gun, so if today’s report becomes a project you want to do, you now have the rest of it.

Part 1
Part 2
Part 3
Part 4
Part 5 read more

The Diana model 50 underlever: Part 5

Posted on by ↓ 72 Comments

by Tom Gaylord
Writing as B.B. Pelletier

Diana 50
Diana model 50 underlever.

Part 1
Part 2
Part 3
Part 4

A history of airguns

This report covers:

  • Move the rear sight
  • Rear sight move forward
  • Change the sight notch
  • Rear sight adjustability
  • Not finished
  • Some disassembly required
  • Three stock screws
  • Wait a minute!
  • Glue the stock
  • Dry mainspring
  • Assembly
  • Velocity check
  • JSB Exact RS
  • RWS Hobby
  • Cocking effort
  • Summary

To give you guys a break from the Crosman MAR177 today I started exploring the History of Airguns web page. Have you seen how the History of Airguns is laid out now? It’s now a simple timeline. Clicking on the dates brings up the past historical articles.

In checking to see whether they all made it to the timeline, I discovered this report from 2017, in which I mentioned wanting to shoot the rifle with an open rear sight. I never did that, so today is the day. I thought I’d just have to move the rear sight but you know how little projects sometimes expand? This one sure did! This will be the tale of what happened. read more

A little about o-rings

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by Tom Gaylord
Writing as B.B. Pelletier

o-rings
An assortment of o-rings.

This report covers:

  • History
  • Flexibility is key
  • O-ring failure
  • O-rings as a face seal
  • O-ring-assortments
  • Hardness
  • Some o-ring facts
  • The seats or channels they sit in help o-rings work!
  • O-rings used other ways
  • Summary

An o-ring is a donut-shaped elastomer (pliable) seal that performs sealing functions for hydraulics and gasses. Airguns use o-rings a lot, and for different purposes. They help us enjoy our hobby with a minimum of fuss. But what do we know about them?

History

The first patent for an o-ring was by the Swedish inventor, J.O. Lundberg. It was granted in 1896. Not much is known about him, but Danish machinist, Neils Christensen who came to the U.S. in 1891, patented the o-ring in this country in 1937. No doubt his work originated from his development of a superior air brake that Westinghouse, a leader in air brake technology since George Westinghouse invented the first fail-safe railroad air brake in 1869, gained control of. In World War II the U.S. government declared the o-ring a critical mechanical seal technology and gave it to numerous manufacturers, paying Christensen a stipend of $75,000 for his rights. Long after the war was over and he had passed away his family received another $100,000 read more

Crosman MAR 177: Part 3

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by Tom Gaylord
Writing as B.B. Pelletier

Crosman MAR
The MAR177 from Crosman.

Part 1
Part 2

History of airguns

This report covers:

  • Baseline with Hobbys
  • Today’s test
  • What is the average?
  • Second page of numbers
  • What does “estimate 601” on page 2 mean?
  • But — what is the average velocity?
  • Photos
  • Pressure gauge and fill pressure
  • Big lesson
  • Balanced valve
  • How do I know the ending air pressure?
  • Air Arms Falcons
  • RWS R10 Match Pistol
  • H&N Finale Match Light
  • Loading problems
  • Loudness
  • Summary

Today I test the velocity of the MAR177 I’m reviewing, and I have a baseline from the 2012 test I did, with which to compare it. Some of you asked me what velocity to expect. Well, it is all in the 6-part review I did on the first MAR177. Look at Part 3 of that series for the velocity test. 

Baseline with Hobbys

In that 2012 test I got an average of 609 f.p.s. from RWS Hobbys and the velocity varied by 32 f.p.s. The low was 593 f.p.s. and the high was 625 f.p.s. I got a shot count of 124 shots on one fill.

Today’s test

Today I shot 160 Hobbys on a fill. The fill pressure ranged from a high of 3200 psi to a low of about 2200 psi — according to my accurate carbon fiber tank gauge. Those starting and ending pressures are well above the pressure range of the first gun (which was 2900 psi to 1600 psi). read more

The Webley Hurricane: Part 4

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by Tom Gaylord
Writing as B.B. Pelletier

Hurricane
Webley Hurricane

Part 1
Part 2
Part 3

A history of airguns

This report covers:

  • The Great Enabler
  • Before we test
  • The velocity table
  • Air Arms Falcon pellets
  • RWS Hobby pellets
  • What happened?
  • A test
  • Crosman Premier Lights
  • Do you see what is happening?
  • But wait!
  • RWS Hobbys
  • Air Arms Falcons
  • A huge lesson!
  • Cocking effort
  • Trigger pull
  • Summary

Today is one of the best blog articles I have ever written. A series of what what looked like minor failures turned around and became a huge success and a fantastic learning opportunity. Today we test the velocity of the recently lube-tuned Webley Hurricane.

The Great Enabler

Spouses beware! Today I will once more demonstrate how I earned the title of The Great Enabler.

Before we test

I was as much in the dark as the rest of you. I had not chronographed the Hurricane until this morning, and I knew as much as you did about what might happen. I did note that the pistol now cocks smoothly, though I doubt it is much easier than before. Maybe just a little because there is no feel from galling. It also shoots very smoothly, where before it had a slight buzz. read more

The Webley Hurricane: Part 3

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by Tom Gaylord
Writing as B.B. Pelletier

Hurricane
Webley Hurricane

Part 1
Part 2

A history of airguns

This report covers:

  • Qualifier
  • Lotsa pix!
  • Begin
  • Remove the stocksides
  • STOP!
  • Roll pin 3
  • Roll pins 4 and 5
  • Safety
  • Remove plastic forend
  • Remove the barrel pivot pin
  • Remove the barrel and cocking link from the gun
  • BB’s first tip
  • Not a lot of spring tension
  • Remove the mainspring and guide
  • Problem identified!
  • What to do?
  • Three lubricants
  • BB’s next tip
  • Test the pistol
  • BB’s final tip
  • Summary

Better put on a whole pot of coffee. This is the longest blog I have ever written.

Here we go — diving into the Webley Hurricane — an air pistol I have never wanted to see the insides of! I was warned about little springs that might fly everywhere. There aren’t any. But there is a sear spring that is attached to absolutely NOTHING, and yet does its job well — IF PUT BACK IN THE GUN THE WAY IT WAS BEFORE IT CAME OUT!

There are several things like that — things the blog that reader Derrick directed us to never mentioned or showed. Things that the Webley manual got wrong!!! My aim is to set the record straight and then to advise most of you to never go inside this pistol or a Tempest. I will show how it comes apart and describe how it goes back goes together, but before you undertake such a task take a look at my qualifier, below. read more