Best of B.B.: Spring gun performance as caliber changes

by Tom Gaylord
Writing as B.B. Pelletier

This report covers:

  • Spring gun performance as caliber changes
  • .177 caliber
  • .20 caliber
  • .22 caliber
  • .25 caliber
  • Results

This is a report I wrote in 2008. I selected it for today’s blog because we have so many new readers that I felt it would be good to go over the basics, again. We’re going to discuss the basics of spring-gun power. This report demonstrates how the muzzle energy of a spring gun increases as the caliber increases.

Spring gun performance as caliber changes

This is an indoor test I’ve wanted to do for more than 10 years. Because I own a Whiscombe JW 75 with all four smallbore barrels, I can test how each caliber performs with the rifle set at one specific power level so I can control as many variables as possible.

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Diana 340 N-TEC Classic air rifle: Part 1

by Tom Gaylord
Writing as B.B. Pelletier

Diana N-TEC 340 Classic
Diana 340 N-TEC Classic

This report covers:

  • What is the 340 N-TEC Classic?
  • Gas-spring advantages and disadvantages
  • The rifle
  • Sights
  • Trigger
  • Shooting impressions
  • Overall impression

Let’s begin our look at Diana’s gas-spring guns. Specifically, we’re testing the Diana 340 N-TEC Classic in .177 caliber. The serial number of the rifle I’m testing is 01583666.

I’m very cautious when testing spring rifles that have gas springs, because dozens of past tests have made me skeptical over the years. The claims for smooth shooting almost never pan out. The claims for accuracy are often inflated. The cocking effort is often played down when I find it to be a major influence in how easy it is to operate the gun.

I’ve seen fewer than 10 air rifles with gas springs that I could recommend to others. So, as I look at this rifle, I’ll be looking from the vantage point of a lot of past experience.

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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.

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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.

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BSA Supersport SE: Part 4

by Tom Gaylord
Writing as B.B. Pelletier

Part 1
Part 2
Part 3

BSA Supersport SE air rifle BSA Supersport SE

This report covers:

• RWS Superdome pellets
• JSB Exact RS pellets
• 8-32X Aeon Classic rifle scope
• Baracuda Match pellets, 5.53mm heads
• Different hold
• Evaluation of the rifle

Today, I’m shooting the .22-caliber BSA Supersport SE at 25 yards. I’m also testing the Aeon 8-32X50 Classic rifle scope with a trajectory reticle mounted in the Diana Bullseye recoil-reducing scope mount. Those 2 products will each get their own separate reports because today I’m concentrating on just the rifle.

In Part 3, I shot the rifle at 10 meters using the open sights that came with it. From that test, I selected a couple pellets to try today. But first, I want to show you a picture of the Aeon 8-32X50 scope mounted on the rifle, because in the last report I mentioned how short it is for this range of power.

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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.

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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.

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