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Ammo Hy Score 807 pellet rifle: Part 4

Hy Score 807 pellet rifle: Part 4

Hy Score 807 peep
Hy Score 807 with target peep sight.

Part 1
Part 2
Part 3

History of airguns

This report covers:

  • Today’s test
  • Diana peep sight
  • Remove the rear sight
  • The test
  • Vibration
  • However
  • Calmer shot cycle
  • Where are we?
  • Summary

Just when you think you have seen it all, something else pops up! Today we look at the accuracy of the Hy Score 807 pellet rifle that is a .22 caliber Diana 27.

Today’s test

I thought today would be a straightforward accuracy test and I was looking forward to being surprised by yet another accurate .22 caliber Diana 27. But that didn’t happen. Let me tell you what did.

Diana peep sight

First I mounted a Diana target peep sight on the rear of the Hy Score. When it was secure I looked through the sight and all I could see was the sporting rear sight notch and the front post. For extra credit can someone please tell me why that was a good thing?

Remove the rear sight

Since it was in the way, the sporting rear sight was removed. Then I could see the front post clearly through the peep hole. I set the sight as far back as it would go which made sighting easy for me.

The test

To get ready for today’s test I read Part 8 of the 9-part report, Tuning Michael’s Winchester 427, where I learned that Falcon pellets from Air Arms did the best. And his rifle did best when shot directly off a sandbag. So that is what I did for today’s entire test. 

I shot 5 shot groups at 10 meters so I could test more pellets. That was fortunate because in the end I shot 11 different pellets. RWS Superdomes worked better than the rest, but they were still not as good as I had hoped. I wanted to find a second pellet that worked better. But nothing did!

807 pellets and gun
I tried many different pellets. Heavy ones, light ones, middleweights. It didn’t seem to make a difference.

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But as I shot, I did notice that the rifle lunged forward with each shot. There was also a small spike of vibration with each shot. I noticed it mostly because when it stopped happening the rifle seemed calmer. And it did stop happening while I was shooting. I’ll tell you about it when we get there.

It took me two shots to sight in and then I shot the first group. But the group was scattered around the bull and not what I had hoped.

The third group was the Superdomes and they did okay, but only just. Five pellets went into 0.535-inches at 10 meters, more or less. I say more or less because the Superdome tears a ragged hole that’s difficult to measure.

I’m not bothering to show you all the groups except in the one photo below, because you get the point. The point being, this Diana 27 isn’t shooting as well as expected.

807 other groups
I shot a lot of pellets but didn’t do very well. The Superdome group is at the top right.


Aren’t you glad there is a “However”? I sure am. When the Superdomes did better than the rest, it started me wondering if RWS Superpoints might do even better. They have long been a favorite for my .22 Diana 27s. But I think I’m out of them. However, I do have those Norma pellets that I have been testing and among them there is a .22 caliber pointed pellet that weighs 14.5 grains. It’s called the Superpoint Strike. I wonder…?

What the heck. At this point I had fired 50 shots and should have been getting tired, but I shot a couple more groups with them, just to see. The first group was five in 0.345-inches. The second group was five in 0.328-inches. And by this point in a test I’m usually getting tired and dipping deep into my excuse bag.

807 Norma group 1
The first group of Superpoint Strike pellets measures 0.345-inches between the centers of the two widest shots.

Following the first group I adjusted the peep sight down and to the left. The second group moved accordingly.

This time five Superpoint Strike pellets went into 0.328-inches at 10 meters. For a second group and with 60 shots under my belt, that’s darn good.

807 Norma group 2
This group of 5 Superpoint Strike pellets at 10 meters measures 0.328-inches between centers.

Calmer shot cycle

But the other interesting thing is the rifle was very quick and calm when it shoots this pellet. It was noticeably different from the other pellets tested. This pellet has a smaller head that this Diana rifle appears to need for best results.

Where are we?

So, where does that leave us? Well, I still do want to disassemble this rifle and to lube it with Tune in a Tube to quiet the powerplant a bit. I also want to clean the ball bearing trigger parts and lube them with light oil. What I’m looking for is a smoother shot cycle and a trigger whose first stage is lighter and more easily felt.


As the famous sage, Rosanne Rosannadanna, wisely said, “It’s always something.” After being surprised by the velocity of this Diana 27 I found myself stumped today by its lack of accuracy. But I think I can do something about that.

I can clean the bore and I can quiet the vibrations with TIAT. It may lose some velocity but there is a lot to spare. We shall see!

54 thoughts on “Hy Score 807 pellet rifle: Part 4”

  1. B.B.,

    The point of the rear and front sight being in the view of the peep sight means that the rifle is already practically sighted in for the peep sight.


      • BB,

        Same here. The comment RSS showed no new post since last Fri., even after hitting refresh. Went to PA site and no new blog shown. Last blog and article was all that was shown and the last comment was from Fri. I went to the Fri. blog and logged in to make a comment and when I did,….. everything was current, including the RSS tab I still had open.

        So,.. it appears that nothing works and is not refreshed unless you are logged/signed in. This has never happened before.

        The way I usually do it is to open the RSS for any missed comments, then read the current blog and then keep the RSS open all day. I do not sign in unless I want to make comment.

        As a side thought, any (new) person will never see anything current.

        I guess I will be logging in first thing everyday now.


        • I was unable to find today’s blog this morning, also. I was starting to think maybe BB had started his holiday early. Instead of logging in, I clicked on Friday’s blog counter (#4296) and right arrowed to today (#4297). Of course I had to log in to comment.

  2. B.B.,
    I had the same experience with others. On my phone, I keep a tab open to /blog/ and simply update or refresh the page to see the latest blog or see if there are new comments to the prior days’ blog posts (whether or not I am logged in). Today, that didn’t work until I logged in. That means the blog is not updating for all the thousands who follow the blog without logging in to make a comment.

    I’m surprised the Norma pellets did the best. You have included Norma-brand pellets in several recent tests, and they always shot inconsistently. You discovered that they were less than uniform. I would be curious after a barrel cleaning and TIAT and trigger work, that you might try some target wadcutters or domes in various head sizes to figure out if this gun likes a certain size.

    I’m happy to report that after cleaning the UX Embark, and installing the peep sight, it shoots everything better, even the cheapies! I am planning on putting my results into a chart and sharing with the folks here.

    Also, I was testing a theory about backstops last night. I filled a cardboard box about 5 inches thick with rubber mulch from lowes and then shot 100 shots into the same spot. Nothing came through the other side! I have an entire copy paper box full of mulch behind that and a 3/4″ sheet of plywood behind that, so I plan to keep abusing that single spot until something penetrates.

    • Hi Roamin Greco,
      You made a comment back on the 21st about my mini-tutorial called, “how to sight in your non-click-adjustable sight in one adjustment.” But I couldn’t reply to your comment as no “reply” box showed up below it (I did “reply” to myself, LOL!). Anyway here is the reply I made (apologies if you have seen it already!):
      thedavemyster June 21, 2021 at 11:22 pm
      Hi Roamin Greco,
      I couldn’t get to a “reply” below your comment, so I had to reply here; yes, a dial caliper or a digital would also work; I like Mitutoyo calipers, perhaps because they are what all the machinists at my first job used. =>
      Take care,
      P.S. I tutored some fellow employees who were taking an algebra course; one guy struggled with it, till I gave him an example to which he could relate: “Your deer rifle is shooting a foot low at 100 yards; your scope bases are 4″ apart; so, how much of a shim will I need to put under the rear mount to bring the rifle on target?” (x/4″ = 12″/3600″; so x = 0.013″) He totally “got” it after I related the math to something that was practical for him!

  3. BB

    This is for IT. I’m using an Apple IPAD. I get notification emails when someone responds. I can edit my comments. I don’t have to log in any more frequently than before. Obviously the upgraded site doesn’t work for readers using different equipment.


  4. I always find myself checking to see what the group size means in terms of minute of angle (MOA). This test shows 3.0 MOA with the pointed pellets, and 4.7 with the Superdomes. That’s not very good. My take on this is that if you get 2.0 MOA, it’s an accurate gun, and 1.0 MOA is what I really want. Going out to 30 yards or more is what you really want, and there are guns/pellets that drop off quickly at distance.

      • 1/4 inch at 25 yds is 0.95 MOA, per that calculator. So – yes!
        And a 3 MOA gun at 25 yds would give you 0.79 inch groups. And there is a dynamic of trying to shoot wadcutters at distance – your target grade rifle is likely to show a bid dropoff much beyond 10 meters.

        • Jerry,

          I think you’ve selected an arbitrary accuracy for all rifles. I’ve seen other people do this and it doesn’t make sense to me to hold a rifle like the Diana 27 to this criteria when it will never shoot to 100 yards.

          I wish I could give a better criteria than this but right now I can’t.


          • Perhaps true, but I have an old Slavia 634 that can get 2 MOA out to 30-40 yds. My Marauder with a Lothar Walther bbl can give me 1 MOA out to about 40 yds. To me, a 2 MOA benchmark is reasonable for a well made/tuned springer and a necessity for competition (field target). I have several guns that can produce 2 MOA (tuned HW97K) and some that can go out beyond 50 (Avenger, Urban). The concept here is that group size and distance can be combined to show accuracy by converting to MOA. There is nothing terrible about a 3 MOA rifle if it has enough other desirable features. My Sheridans can do that, and I’m very fond of them.

        • Jerry

          Thanks, your MOA calculator certainly is convenient. I have read the interesting comments below from others. The MOA method seems as good as any for measuring accuracy within a reasonable range for a given gun and projectile. But I have another question. If you have a gun that consistently delivers 1 MOA accuracy at 25 yards, will it always average .1145 inches or better at 10 meters using the same pellet?


          • Yes, I believe that accuracy at distance is more challenging as it is more dependent on pellet ballistics. So it ought to hod as tight a pattern at close range.

    • Thanks for the link Jerry!

      Just checked and I’m getting .6 to .8 MOA @40 yards with my .22 Impact, pleased with that! Now that I have a base line it is time to start shooting at 45 yards.

      Everyone has their preferred way of gathering stats eh? I think that groups are an OK way of measuring consistency but I am more concerned with precision – I measure the difference between POA and POI for my notes.


    • I’m not sure that a linear application of that formula is entirely possible, ie, 1/4” at 25 will equal 1” at 100. Predicting a cone of fire or angle of dispersion from a single data point is fraught with annoying realities. Diabolo shaped pellets, reliable as they are, can be very sensitive to launch speeds (among other factors). Launch speed affects trajectory distance. Trajectories are parabola shaped due to gravity. At best, one might hope for a lozenge shape at distance that correlates to the near data point.

      • The formula is pure math, 1″ at 100 yds is just the most common approximation. Of course, in practice you have all the factors like hold, wind, pellet fit, etc. etc. I say shoot ten pellets with as much control as possible, measure group size, and then calculate MOA result. My own goal is to get 1 MOA with my Marauder to be ready for field target. In this competition, you will need 1-2 MOA reliably out to 55 yards for the best results, and you will need it to hit the 1/4″ kill zones at 10 yards, too. And of course, we are not shooting laser beams, so there are many factors in play. Pellet selection is high on the list.

        • JerryC: I hope to achieve that level someday. Right now, I’m happy with RidgeRunner’s “minute of popcan.” But I also look forward to determining at what range I can hold all my shots into an inch, as BB recommends as an effective hunting range and then extending that. I guess how you track your performance determines the standard you measure by. Probably the same reason some prefer Extreme Spread and others Standard Deviation. It comes down to what you are trying to achieve or predict. To me it does not seem to be a matter of right or wrong. As long as we keep shooting and having fun!

  5. B.B.

    Finding the preferred pellet is always an interesting journey through “I wonder why” eh ? 🙂

    Surprised that you mentioned cleaning the barrel now. My usual MOA is to clean barrel and re-season then check scope and stock hardware before I start any testing. Guess I am just a creature of habit 🙂

    Happy Monday all!

  6. If anyone knows where I can find a good used peep sight with an adjustable iris for a Beeman R7, I would be most appreciative. I think I’m close to maxing out my airgun budget for a while, but I found the one I have on the kids’ Embark would likely not stay put on the R7. I find myself checking the thumbscrew clamp on it after every group after finding it loosening last night, even on the Embark.

    • RR
      Well that answers what I thought would happen about what we talked about on the other days blog.

      Now you got to get the steel breech so you can have a dovetail.

        • RR
          Don’t forget the rear sight on a 2240 can be rotated 180° to make a rear peep sight.

          Next step is to figure out how to make the front post sight a globe.

          Or can you leave the front sight alone and use it with the factory rear peep on the 2240 and 1377/22. The answer is yes you can. 🙂

          • GF1,

            I did not know that about the 2240 rear sight, but that is useless information until a shoulder stock is installed.

            Peeps and globes are no biggie for me. Now that trigger really needs some work. It is quite obvious that the attorneys did not want these things going off accidentally. It has a way to go yet.

            This pistol has potential. We will see where it goes.

    • RR,
      Now now. You didne have to enter the lottery! No one was twisting your arm bar yourself. and infact we won’t mention that you didnae … * volume turned down *

      BTW Nice g r i p s !

      So now you need a metal breech, trigger upgrade, pistol scope, barrel weight, HPA adapter? high volume internals, adjustable hammer spring, regulator ???

      But wait, how is it shooting? Is it loud? Silencer? Is it fiddly to load? Magazine?

      : – ) Robert.

  7. “This time five Superpoint Strike pellets went into 0.328-inches at 10 meters. For a second group and with 60 shots under my belt, that’s darn good.”
    Not only is that pretty darn good, the rifle is a pretty sweet looking rig with that peep sight on it! =>
    Looking forward to the rest of this series,

  8. B.B.,

    Still can’t get to Hy-Score Part-4 without jumping through flaming hoops!
    I’m not using some off brand of browser: Chrome on an up-to-date ANDROID Tablet!

    A-l-m-o-s-t Intolerable when 50% of the posts are like this one not airguns!
    IT needs to get this FIXED PRONTO before it kills off your blog!


      • Yes, exactly. When I did my morning routine; prayer, coffee, blog, I did, indeed, think that BB had gone walkabout. Most of the time I lurk, logging in only to offer some pearl of wisdom. Curiouser and curiouser. For the IT folk, I am using an iMac, os 10.13.6.


  9. BB,
    Keeping the open sights on with the peep is beneficial:
    IF the barrel droops OR sits up, you can plainly see this and reschedule the peep.
    The peep increases “depth of field” so that your open sights actually are in focus as well as the target.!!!

    If you had a ring at the breech end that was just the correct dimension, you could have a hybrid sight. The ring just needs to be visible enough to keep an eye on the barrel droop. If you see the barrel is dropping you can compensate with a few clicks. There is just no way I would trust a break barrel to re align 100% true every time. People with break barrels+scopes must realise this…. that is why under levers etc are “more accurate”. Robert.

    PS Well at least the Edit function is back, but the faded grey font colour is hard on the eyes… why on earth would someone design the font to be GREY ??? I need binoculars to read what I am writing…. AND the CANCEL button right next to the SAVE button… SMH.

  10. B B,
    Thats not bad accuracy at all but I agree that it should do better. I think cleaning the barrel then trying some Meisterkugelen is where I would go first. I must say that this 27 is producing greater power than I would expect to see. It may be that its moved out of its sweet spot a bit at that level.
    I may be clutching at straws a bit but I hope you can get it to where you need it.


    p.s. The 27 blog post didn’t appear for me until today, 29th.

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