The Diana model 50 underlever: Part 6

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


The Diana model 50 underlever: Part 5

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


Air Arms Pro-Sport: Part 6

by Tom Gaylord
Writing as B.B. Pelletier

Pro-Sport
Air Arms Pro-Sport.

Part 1
Part 2
Part 3
Part 4
Part 5

This report covers:

  • Evil BB!
  • Report on the Meopta scope
  • Sight-in
  • The test
  • Refine the sight-in
  • However
  • Hurray!
  • What have we learned?
  • The second However
  • H&N Baracuda with 5.50mm head
  • Next
  • Summary

Today we test the Air Arms Pro-Sport with the Vortek PG3 tune kit I installed and tested in Part 5. But first I have to clear up a misconception.

Evil BB!

Somewhere along the line you may have read that I said the Meopta MeoPro Optika6 scope came without scope caps. It wasn’t really me who said that! It was my evil twin cousin, BB Airgundart! He sometimes sneaks into my house and messes with the blog without me knowing it. The Optika6 has a very nice set of scope caps with their logo on both caps. I found them on my somewhat cluttered desk, in the detritus just above the Cambrian layer!

Report on the Meopta scope

In Part 6 of the Dreamlite report I mentioned that the illuminated dot was flashing in my Optika6 scope. Meopta, who follows this blog, read that and informed me that dot is never supposed to flash. It’s supposed to remain solid on all 6 brightness settings, and the flashing does not indicate the battery is running down. They asked me to return the scope so they could examine it, and they promptly sent a replacement. What I had neglected to report to you in the first report on the scope is that it comes with a lifetime warrantee!

Thanks to them I am back in business with what is the finest riflescope I have ever owned, and I’m putting it on the Pro-Sport that I’ll be shooting today. I’m mounting it in the Sportsmatch 30mm adjustable rings and the scope just fits the rifle! Let’s look.

Pro-Sport Meopta scope
The Meopta MeoPro Optika6 scope is mounted on the Pro-Sport. As you can see, it does have scope caps. When the eyepiece is positioned correctly the scope objective lens just clears the loading port by less than a quarter-inch, making it perfect for this rifle!

I forgot just how clear and sharp this scope is. Or maybe my eyes are better this time when I used it. I did not need the illumination to see the dot over the 10-dot on the target at 25 yards.

Sight-in

I sighted in from 12 feet, which is a benefit we airgunners have. The pellet landed about 1.5 inches below the aim point and a little to the left, so the elevation was ideal for 25 yards (the approximate distance between the center of the scope and the center of the bore is 2-inches, and that is about how low the shot should be at 10-12 feet), so I put in 4 clicks of right adjustment and went back to 25 yards to begin the test.

The test

I will shoot a couple 10-shot groups from 25 yards. My goal today is not to see whether the Pro-Sport is accurate. That was established in Part 3. My goal today is to report on the smoothness of the Vortek PG3 tune and also on the performance of the Meopta scope on a spring-piston air rifle.

You will remember that Meopta wasn’t initially keen on making scopes for recoiling air rifles. But they did make this line whose parallax adjusts to 10 yards. I have already tested it on two precharged pneumatics — a very accurate Air Arms S510XS and also on a

.177-caliber FX Dreamlite read more


Umarex Synergis repeating underlever combo: Part 1

by Tom Gaylord
Writing as B.B. Pelletier

Umarex Synergis
Umarex Synergis underlever repeating gas piston rifle.

This report covers:

  • Underlever spring gun repeater?
  • The rifle
  • Magazine
  • Sights
  • Fully shrouded barrel
  • Trigger and safety
  • Cocking effort
  • Accuracy
  • Feeding
  • Summary
  • read more


    Chinese B3 underlever: Part 7

    by Tom Gaylord
    Writing as B.B. Pelletier

    B3
    The B3 underlever from China.

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

    A history of airguns

    This report covers:

    • Refresher
    • The test
    • Sig Match Ballistic Alloy
    • Sight adjustment
    • On a roll?
    • Air Arms Falcon
    • POI change
    • RWS R10
    • Best for last
    • JSB Exact RS
    • Summary

    Today was day of learning, or perhaps I should say remembering, because today’s test of the Chinese B3 underlever took me back to my early days with spring-piston air rifles. I will explain as the report unfolds.

    Refresher

    I found this tired old air rifle in a pawn shop many months ago. In this series I have replaced the breech seal with a faucet washer, opened up the powerplant, lubricated the moving parts with Tune in a Tube and shot the rifle for accuracy. That was when I discovered how accurate this old Chinese underlever is. So I vowed to shoot it for accuracy once more, now that the powerplant has been tamed.

    The test

    I shot the B3 from a sandbag rest at 10 meters. I used the artillery hold, with my off hand back by the front of the triggerguard.

    Sig Match Ballistic Alloy

    In the last test Sig Match Ballistic Alloy pellets were the clear favorites, so I started this test with them. I knew they were not zeroed, but I let that go for the first 10 shots. The first 5 of those shots gave a very tight group, but the final 5 opened up considerably. I was wearing reading glasses to see the front sight, but after the group was over I felt I hadn’t concentrated on the front sight well enough.

    Sig Match group 1
    Ten Sig Match Ballistic Alloy pellets made this 1.027-inch group at 10 meters. The first 5 shots were almost half that size.

    This is so much larger than the 10-shot group I shot with the same pellet in Part 4 that I knew something wasn’t right. In fact, that earlier 10-shot group was probably smaller than the first 5 shots on this day. I had to try again.

    Sight adjustment

    The Sig pellets hit to the left and a little below the aim point, so I adjusted the rear sight right and up. I also decided to just shoot 5-shot groups from this point so I could maintain my concentration on the front sight. This group did move up and to the right a little, but not as far as I had hoped. However, by concentrating on the front sight I managed to put 5 rounds into 0.328-inches at 10 meters. That’s a group!

    Sig Match group 2
    On the second try, 5 Sig Match Ballistic Alloy pellets made this 0.328-inch group at 10 meters. It’s the best of the test.

    On a roll?

    I hoped this group was a forerunner of great things to come. I wanted to try a domed pellet next.

    Air Arms Falcon

    Next up was the Air Arms Falcon dome. I shot them in the velocity test after the lube (Part 6) and they did very well. But not on paper! Five Falcons made an astonishingly large 1.769-inch group at 10 meters.

    Falcon group
    Five Air Arms Falcons went into 1.769-inches at 10 meters.

    POI change

    That is a horrible 10-meter group, but look where its center is. It’s high and to the right of the center of the bull. I did not change the sights after the last group of Sig pellets This is what I meant when I said at the beginning that today’s test took me back to my early days with spring-piston air rifles. In those days you had to test all pellets — both for accuracy as well as for the point of impact. Each pellet had the potential to land in a completely different place, and you never knew where that was unless you tested them all. This B3 is from that time period, so I guess it’s performing like the old rifles did.

    RWS R10

    Since the Sig Match pellets are so accurate I wondered whether other match pellets might also be good. Of course I’ll never know unless I test them all, but for today’s test I shot the RWS R10 Match Pistol pellets. While they are still expensive, they are half the price of the Sig Match pellets, so I was hoping they would be good in the B3.

    Five R10 pellets went into 0.361-inches at 10 meters, which makes them very accurate. On top of that, they moved to almost dead-center on the bull without any sight adjustment! This group is dramatic in two ways!

    RWS R10 group
    Five RWS R10 Match Pistol pellets made this 0.361-inch group that’s very close to being centered.

    Best for last

    The B3 rifle is showing a level of accuracy I have never seen in any other Chinese underlever from this timeframe. I have heard people make claims like this, but I always wrote them off as random groups. Now I see different. But I still wondered whether I could get accuracy with a domed pellet that I would be more likely to shoot in this rifle, and also one that is more affordable.

    JSB Exact RS

    The pellet that came to mind was the JSB Exact RS dome. They are a premium pellet, but also affordable to those who value accuracy. They are often accurate in lower-powered spring guns, which the B3 certainly is. They seemed perfect for this test.

    Five RS pellets went into a group measuring 0.421-inches between centers at 10 meters. And just as good, they went high and are almost exactly centered with the bull. That means I can adjust the rear sight back down and be perfectly sighted in. This is the pellet for the B3!

    JSB Exact RS group
    Five JSB Exact RS pellets landed in a group measuring 0.421-inches between centers at 10 meters. Better than that, the group is almost centered, left to right, and about 1.2-inches high. read more


    Chinese B3 underlever: Part 6

    by Tom Gaylord
    Writing as B.B. Pelletier

    B3
    The B3 underlever from China.

    Part 1
    Part 2
    Part 3
    Part 4
    Part 5

    A history of airguns

    This report covers:

    • Pre-work baseline
    • RWS Hobby
    • Harsh firing cycle
    • Rifle is breaking in
    • Air Arms Falcon
    • Sig Match Ballistic Alloy
    • RWS Hobby again
    • Discussion
    • Cocking effort
    • Trigger pull
    • Summary

    Today I will test the velocity of the B3 underlever that we cleaned and lubed on Friday. This will be a fantastic learning lesson for all airgunners, because the results are most informative!

    Pre-work baseline

    If you have been following this report you know I discovered in Part 2 that the rifle wasn’t performing to expectations. In Part 3 I replaced the breech seal and tested the velocity. That gave us a baseline we can use today for a before and after comparison. Let me get to the tests right now.

    RWS Hobby

    The first pellet to be tested was the RWS Hobby. In Part 3 Hobbys gave an average 617 f.p.s. with a 24 f.p.s. spread.

    Now let’s look at how the lubed B3 did with Hobbys. Because of what happens in this string, I’m showing you every shot, and will then discuss it.

    Shot………Vel.
    1………….did not register (DNR)
    2………….572
    3………….604
    4………….814 diesel
    5………….822 diesel
    6………….815 diesel
    7………….805 diesel
    8………….774 smoother
    9………….743
    10…..…….737
    11…..…….734
    12…..…….688 smooth!
    13…..…….725
    14…..…….705

    Then, I had to take a short break and retire to my reading room. Let’s say I stopped shooting for 5 minutes.

    15…..…….546
    16…..…….565
    17…..…….578
    18…..…….567
    19…..…….582
    20…..…….689
    21…..…….571
    22…..…….699
    23…..…….619
    24…..…….557
    25…..…….DNR
    26…..…….570
    27…..…….661
    28…..…….DNR
    29…..…….DNR
    30…..…….576
    31…..…….564

    At this point I stopped shooting. Let’s look at these results and see what is happening. First, shot number 4 was a diesel — not a detonation. Dieseling is where the oil vapor is burning from the heat of compression and adding to the velocity, but there is no loud explosion like you hear with a detonation. Dieseling is normal and even good. Apparently this B3 is right on the cusp of dieseling, and, as I told you on Friday, I had saturated the leather piston seal with Crosman Pellgunoil. I could see oil droplets (in a fine mist) being expelled from the muzzle with every shot. That’s exactly what you want to see in an airgun that has a leather piston seal.

    Harsh firing cycle

    I told you Friday that the firing cycle became much smoother after the gun was lubricated. And the first three shots in this test were all very smooth. But the shots where I noted the dieseling were harsher than the others. They were almost as harsh as the shots from the time before the rifle was lubricated.

    Notice that I said shot number 8 was smoother. I meant smoother than shots 4 through 7. The gun was still dieseling, but it was starting to settle down. Shot 12 was very smooth — about like what I saw in shots 2 and 3.

    Rifle is breaking in

    The reason I said today’s report is so special is that this string shows you what an airgun goes through as it breaks in. The B3 is a used gun, so what is breaking in and settling down is the oil on the piston seal. That’s why I wanted you to see the entire string — so you would appreciate what it looks like (and feels like) when a spring-piston air rifle breaks in.

    If I were to look at this string and guess the final average velocity of this rifle with Hobby pellets, I would say 560 to 570 f.p.s. But — it ain’t over, yet! I decided that, because the rifle was settling down, I could now test the other pellets.

    Air Arms Falcon

    Next to be tested were Air Arms Falcon pellets. In the before test they averaged 605 f.p.s. with a 27 f.p.s. spread. I’m going to show you the entire string from this test, and then discuss it.

    Shot………Vel.
    1………….565
    2………….564
    3………….565
    4………….562
    5………….561
    6………….566
    7………….568
    8………….559
    9………….564
    10…..…….561

    This string tells me the rifle has settled down, and that’s why I showed it to you. The average for the string is 564 f.p.s. and the spread ranges from 559 to 568 f.p.s. — a mere 9 f.p.s. That would be good for an expensive spring rifle!

    Sig Match Ballistic Alloy

    Next I tried 10 Sig Match Ballistic Alloy pellets. Remember how very accurate they were at 10 meters? In the before test these same pellets averaged 688 f.p.s. with a 32 f.p.s. spread.

    I won’t show the whole string this time, but the average velocity was now 628 f.p.s. and the spread went from 624 to 633 f.p.s. That’s another 9 f.p.s. spread! This rifle has definitely broken in with the lube I gave it.

    RWS Hobby again

    It was time to revisit the RWS Hobby, to see what the actual average was. Remember, after looking at the first string I guesstimated it would be in the 560 to 570 f.p.s. range.

    The average this time was 541 f.p.s. The spread went from 534 to 547 f.p.s. — a range of 13 f.p.s. Well, the gun has definitely settled down and I was definitely estimating too high when I guessed based on the first string.

    Discussion

    Before the lubrication Hobbys averaged 617 f.p.s. with a 24 f.p.s. spread. After the lube Hobbys averaged 541 f.p.s. with a 13 f.p.s. spread. The rifle has lost 76 f.p.s. and the velocity spread has been cut almost in half.

    Before the lubrication Falcons averaged 605 f.p.s. with a 27 f.p.s. spread. After the lube Falcons averaged 564 f.p.s. with a 9 f.p.s. spread. That’s a loss of 41 f.p.s. and a two-thirds reduction of the spread.

    Before the lubrication Sig Match Ballistic Alloy pellets averaged 688 f.p.s. with a 32 f.p.s. spread. After the lube they averaged 628 f.p.s. with a 9 f.p.s. spread. That’s a loss of 60 f.p.s. and a reduction of the spread by more than two-thirds.

    So the lube tune I did has cost me between 41 to 76 f.p.s. in a rifle that wasn’t very fast to begin with. I’m pretty sure that loss can be attributed to the use of Tune in a Tube grease on the mainspring, because I didn’t do much else. The oiling of the piston seal probably didn’t help or hurt the velocity, though it will prolong the life of the seal.

    Cocking effort

    The B3 took 32 lbs. of force to cock before the tune and it still takes that much. Before the tune I felt some spiking near the end of the cocking stroke and now that the action is lubed I can tell it is from the trigger parts being pushed out of the way by the piston. I can tell that because the rest of the cocking stroke is now much smoother.

    Trigger pull

    Before the lube the trigger broke cleanly at 5 lbs. 3 oz. After the lube it breaks exactly the same. Remember — I did not lube the trigger in any way, nor do I feel the need to. I know that sounds like a heavy trigger to many readers, but I grew up with military rifles and 5 lbs. is where they have always been. Even today a stock M4 or M16 is at that weight. So it seems normal to me. I also like lighter triggers like most shooters, and I really like crisp 2-stage triggers, but I am very satisfied with the trigger on this rifle.

    Summary

    I think today’s test was an important one for those who are trying to understand spring-piston air rifles. While a tune doesn’t change the accuracy potential of an airgun, I feel this B3 now shoots so well that I want to test it for accuracy again.


    Chinese B3 underlever: Part 4

    by Tom Gaylord
    Writing as B.B. Pelletier

    B3
    The B3 underlever from China.

    Part 1
    Part 2
    Part 3

    A history of airguns

    This report covers:

    • The test
    • RWS Superdomes
    • Sig Match Ballistic Alloy
    • Firing behavior
    • RWS Meisterkugeln
    • Qiang Yuan Training pellets
    • Trigger
    • Summary

    This is accuracy day! Today we will learn how accurate my new/old Chinese B3 underlever spring-piston air rifle is. This is the rifle with the replaced breech seal that we learned in Part 3 is such an easy fix. Today we see whether it matters.

    The test

    I shot at 10 meters off a sandbag rest. I used the classic artillery hold with the off hand next to the front of the triggerguard and rested on the sandbag.

    I resolved to shoot just 5 shots, unless the pellet looked like it might group. If it did I would go to 10 shots.

    RWS Superdomes

    First up was the RWS Superdome. The first shot hit the target at the lower edge of the bull, but shot two hit above the 10-ring. I shot the next three shots and then looked at the group and decided this is not the right pellet for this rifle. The 5-shot group later measured 1.37-inches between centers.

    RWS Superdome group
    The B3 put 5 RWS Superdomes into 1.37-inches at 10 meters.

    No sense going any farther with Superdomes. Oh, well! I have never had any luck with Chinese springers. I will say that the rear sight was easiere to use than I thought it wouuld be — being that close to my eye.

    My next Sig Match Ballistic Alloy pellet hit very low, so I adjusted the rear sight up quite a bit. Even then it didn’t raise the point of impact up to the aim point.

    Sig Match Ballistic Alloy read more