RWS Diana 45: Part 10

by Tom Gaylord
Writing as B.B. Pelletier

Part 1
Part 2
Part 3
Part 4
Part 5
Part 6
Part 7
Part 8
Part 9

RWS Diana 45 air rifle
Diana 45 is a large breakbarrel spring rifle.

This report covers:

  • Cause to reconsider
  • More black tar?
  • What is black tar grease?
  • A quick job
  • Velocity
  • Summary

Today’s report is an unprecedented test. I thought I’d finished the report on the Diana 45 in Part 9, but it still bothered me that I couldn’t get the last bit of vibration out of the gun. I chalked that up to the high number of parts in the rifle’s powerplant. Too many things to make quiet.

Cause to reconsider

Then two things happened that caused me to reconsider. First, while at the Malvern airgun show, I saw and shot a fabulous HW85 that had been tuned by Bryan Enoch. It was stunningly calm. When I talked to him about his tune, Bryan told me that he put a thin coat of black tar grease on the mainspring before he assembled the rifle. That caused me to stop and think — because that tune was perfect. read more


RWS Diana 45: Part 9

by Tom Gaylord
Writing as B.B. Pelletier

Part 1
Part 2
Part 3
Part 4
Part 5
Part 6
Part 7
Part 8

RWS Diana 45 air rifle
Diana 45 is a large breakbarrel spring rifle.

This report covers:

  • First shot at 12 feet
  • Firing behavior
  • At 25 yards
  • First group
  • Second group
  • Velocity retest
  • Overall evaluation

Today, I’m testing the tuned Diana 45 at 25 yards. This time, I’ll use a scope. I mounted an obsolete CenterPoint 3-9X40AO scope on the rifle. Because this is a vintage Diana rifle, which is always a drooper, I used a UTG drooper scope base. The one I used was a prototype that was left from when I was testing different base angles for Leapers. I selected one with a very slight droop of a couple degrees — less than what you can buy from Pyramyd Air.

First shot at 12 feet

I always sight in close to the target, so I know that I’m on when I move back to 25 yards. I was so close that the target was blurry in the scope with the parallax set as close as it would go. read more


RWS Diana 45: Part 8

by Tom Gaylord
Writing as B.B. Pelletier

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

RWS Diana 45 air rifle
Diana 45 is a large breakbarrel spring rifle.

This report covers:

  • RWS Superdome pellets
  • Uh-oh!
  • RWS Hobby pellets
  • Air Arms Falcon pellets
  • Time to stop and think
  • H&N Baracuda Match pellets with 4.53mm head
  • Where we are

Today, we’ll look at the performance of the Diana 45 that we tuned recently. Although a new mainspring was installed, it has the same power as the spring that was in the rifle, so no vast power increase was anticipated. If there’s any increase at all, it will probably come from the new breech seal I installed. The old one was flat and hard, so the breech is probably sealing air better now.

The point of this tune was to eliminate as much vibration as we could. The rifle’s owner, Johnny Hill, did not like the buzz that came with every shot, and I told him that most or even all of that could be eliminated by tightening the tolerances inside the powerplant. At my request, he made a larger spring guide, and he buttoned the piston to take out as much vibration as possible. read more


RWS Diana 45: Part 7

by Tom Gaylord
Writing as B.B. Pelletier

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

RWS Diana 45 air rifle
Diana 45 is a large breakbarrel spring rifle.

This report covers:

• Barrel must go on
• Piston into the tube
• Piston liner and cocking shoe go in
• Install the barrel
• Install the trigger
• Install the barreled action in the stock
• Quick function test

Barrel must go on
I’ll pick up where I left off in the last report. To assemble the parts, the barrel has to go on the spring tube. During disassembly, I’d noticed during that the breech seal was flattened and hard, so it was replaced before anything else was done. It’s just an o-ring with a steel spacer underneath, so the old one was pried out and a new one was pressed into the groove. read more


RWS Diana 45: Part 6

by Tom Gaylord
Writing as B.B. Pelletier

Part 1
Part 2
Part 3
Part 4
Part 5

RWS Diana 45 air rifleDiana 45 is a large breakbarrel spring rifle.

This report covers:

• Piston head swaged
• Eliminate sloppy tolerances
• Buttons
• Tighter spring guide
• Remove all burrs
• Clean the spring tube
• Lube the spring tube
• Lube the piston, piston liner and mainspring
• Lube the leather piston seal
• Leave the trigger alone

Today, I’ll show you all the things that have been done to the Diana 45 parts; and I’ll clean, lubricate and assemble the rifle. This will be a long report, so I am breaking it into two parts — today and tomorrow.

Piston head swaged
Before we get to the job though, I was asked by one reader to show how the piston head is attached to the piston body. If you want to replace the leather piston seal, the piston head has to be removed — and that isn’t going to be easy, because it is mechanically swaged onto the piston body. read more


RWS Diana 45: Part 5

by Tom Gaylord
Writing as B.B. Pelletier

Part 1
Part 2
Part 3
Part 4

Diana 45
Diana 45 is a large breakbarrel spring rifle.

This report covers:

• Remove the barrel
• Barrel off!
• Remove the piston
• Disassembly is complete
• One last look

We have a lot to cover today, so let’s get right to it. We left the Diana 45 with the mainspring out of the gun at the end of yesterday’s report. The only thing left in the disassembly is to remove the piston. Do not disassemble a gun if you’re not 100% certain you can put it back together again in safe working condition!

Remove the barrel
The piston will not come out of the gun until the cocking link that connects it to the underside of the barrel (for cocking) is removed. To do that, you must first separate the barrel from the spring tube. That step is easy on some breakbarrels, but not so easy with this 45. On most breakbarrels, you remove the pivot bolt from the action forks and the barrel separates from the spring tube. The Diana 45 has another step; and unless you follow it, the barrel will never come off the gun. read more


RWS Diana 45: Part 4

by Tom Gaylord
Writing as B.B. Pelletier

Part 1
Part 2
Part 3

Diana 45 left
Diana 45 is a large breakbarrel spring rifle.

This report covers:

• Remove the stock
• Action out!
• Action in mainspring compressor
• Trigger assembly is free
• Spring bent!
• Gun is dry
• The rest of the powerplant
• Last word

I’m changing things for this report just a bit. In part 3, I told you that I would do a 25-yard accuracy test next. I’ve decided to forego that step and start working on the tuneup, instead. Today, I’ll show how to disassemble a Diana 45. Make certain the rifle is uncocked before you begin. Do not disassemble a gun if you’re not 100% certain you can put it back together again in safe working condition! read more