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Education / Training Hy Score 807 pellet rifle: Part 2

Hy Score 807 pellet rifle: Part 2

Hy Score 807
Hy Score 807

Part 1

History of airguns

This report covers:

  • Adjusting the trigger
  • Velocity
  • RWS Hobby
  • Air Arms Falcons
  • Discharge noise
  • RWS Meisterkugeln
  • Here’s why
  • Whaddaya do?
  • Hobbys again
  • Falcons again
  • Meisterkugen
  • However
  • Cocking effort
  • Where are we?
  • Summary

Today BB finds out how healthy his new/old Hy Score 807 is. This is going to be a good one!

Adjusting the trigger

I couldn’t believe that someone online said that, “Adjusting the trigger is notoriously difficult.” It couldn’t be much easier when you know what you’re doing. There are two screws. Loosen the front one (the one farthest from the trigger blade) shown in the pic and then adjust the rear screw. 

adjust 807 trigger
Loosen the front screw, adjust the rear screw, tighten front screw and you’re done!

I adjusted the rear screw one turn counter-clockwise and got too much first stage travel with too light a let-off. Back 1/4 turn and it was perfect. Tighten the front screw and I was done in three minutes.

I will say this, stage two on the ball-bearing trigger can be hard to find until the trigger is exercised a couple times. So shoot the gun a couple times or hold onto the barrel while pulling the trigger a couple times and the first stage becomes clearer (more obvious, with a positive stop at stage two). Tighten the front screw when you are satisfied and the trigger should remain where you adjusted it.

The first stage now measures 2 lbs. 2 ounces and the stop at stage two is positive. Stage two breaks at 2 lbs. 5 ounces, so the stage two pull is just a razor-thin three ounces.This is a trigger I can work with.


Today I am going to test velocity with three different pellets, but a funny thing happened during the test. As I shot the rifle became faster and faster. I know why and you will too, if you read along.

RWS Hobby

The 11.9-grain RWS Hobby was the first pellet I tested. They averaged 472 f.p.s. with a 13 f.p.s spread from 466 to 479 f.p.s. But that wasn’t right, and I didn’t know it yet.

Air Arms Falcons

The second pellet I tested was the 13.43-grain Falcon from Air Arms. They averaged 430 f.p.s. with a 29 f.p.s. spread from 415 to 444 f.p.s. But that wasn’t right, yet, either.

Stock Up on Shooting Gear

Discharge noise

While shooting the Falcons I set up the sound meter on my smart phone three feet from the muzzle and recorded a discharge of 100.5 dB. That’s louder than I expected it to be. I think the device is also picking up the sound of the pellet hitting the steel plate in the bullet trap, so I have more work to do on my garage testing area.

807 discharge
The sound was louder than I expected.

RWS Meisterkugeln

The third and final pellet I tested was the 14-grain RWS Meisterkugeln that should have been the slowest of all. Except it wasn’t. Ten of them averaged 467 f.p.s., with an 18 f.p.s. spread from 458 to 476 f.p.s. They were almost as fast as the 2 grain-lighter Hobbys. Why?

Here’s why

This rifle was speeding up! The more I shot the faster it became. And with a spring piston rifle that has a leather piston seal that means just one thing; the piston seal is becoming more flexible. It’s sealing the compression chamber better.

So, let’s see — when did I oil this rifle’s piston seal? Oh, right. Never! To quote the immortal words of Jar Jar Binks, “My forgot!” And the leather piston seal was warming up as I shot to take care of the situation.

Whaddaya do?

There is only one thing to do. Shoot those first two pellets again.

Hobbys again

On the second string, RWS Hobbys averaged 493 f.p.s. — a full 21 f.p.s. faster than the first time. This time the spread was 8 f.p.s., from 488 to 496 f.p.s. Okay — now we are cookin’!

At the average velocity this rifle with this pellet generates 6.42 foot-pounds.

Falcons again

Falcons the second time around averaged 439 f.p.s. Not quite the same increase as the Hobbys, but the extreme spread was 31 f.p.s. So this is an erratic pellet in this rifle. At the average velocity they generate 5.75 foot-pounds.


I didn’t shoot a second string of Meisterkugeln. I felt the rifle had climbed as high as it was gonna go. At the average velocity they generate 6.87 foot-pounds. The heaviest pellet should not be the most powerful with a vintage spring-piston rifle, but since this one is I think there is still some more warmup/break-in to go. I did shoot one final Hobby that went through the skyscreens at 507 f.p.s., so, wow!


When I shut down the chronograph (it’s in the garage now) and got back in my office I did drop five drops of Crosman Pellgunoil down the muzzle as the rifle stood on its butt. I will be taking this rifle apart, just because we all want me to, but I’m believing that piston seal is pristine.

Cocking effort

The rifle has what feels like a fresh mainspring. It cocks with 22 lbs. of effort. Fortunately with this rifle there is no safety, no beartrap and you can uncock it by pulling the trigger and letting the barrel close slowly.

Where are we?

I thought this rifle needed to be tuned. It apparently doesn’t, but I’m going to anyway because I want to. After tuning my other 807 with Krytox and discovering that is doesn’t dampen vibration, I will use Tune in a Tube on this one.

The trigger is now adjusted well, but I will be sure to lubricate the ball bearings to make it as smooth as possible.


There is a lot in store for this Hy Score 807. The rear sight is missing parts but I plan to mount a Diana target peep sight, to see what this old girl can do. It should be fun!

76 thoughts on “Hy Score 807 pellet rifle: Part 2”

    • Siraniko
      Everybody better get thier TIAT now.

      They say that big fire that happened at that grease company in northern Illinois is suppose to be the biggest supplier of grease around.

      We are already stocking up at work with grease because of the fire and possible shortage.

  1. BB,

    how does the trigger compare to the Rekord in your opinion?

    Interesting that you mention the second stage getting clearer with some use. I noticed the same thing with the Diana LP 5 even though that trigger seems to be entirely different from the one in the 27.
    As far as the LP 5 is concerned, I would say the trigger is good, but the ones on the HW45 and HW75 are even better.

    Kind regards,

    • Stephan,

      Oh the Rekord is much better. It has a positive first stage and doesn’t need to be worked to feel stage two. And there is so much more flexibility in how heavy stage two is, compared to stage one.


  2. B.B. and everyone. I received a shipment from Pyramyd AIR yesterday that included a new Air Venturi Rear Sight, Micrometer Adjustable, Peep Sight. I was excited to slap this on the kids’ Embark. The first problem was that there was a piece of metal screwed to the top of the back end of the rail. I think that is some type of scope stop.
    I removed the screw holding that piece of metal and it came off easily. Then a plastic piece covering the rear portion of the spring tube was in the way and wouldn’t let the jaws of the peep sight clamp on the rail. So I took off the stock and slipped off that piece of plastic. After I put the stock back on, I was able to clamp on the rear sight. Looking through the peep sight’s aperature, all I could see was the rear sight. So to remove the rear sight, I had to unscrew the elevation knob all the way out, which allowed the sight to unfold along the hinge on the front of the sight, revealing the two screws holding the sight to the rifle and a spring. Upon removing those, all that was left was a tall Allen screw that the elevation knob was screwed to originally. I removed that, too. So my first question is, does all that sound normal?

  3. “Fortunately with this rifle there is no safety, no beartrap” …imagine that – the user is solely responsible for safe practices! What a concept!

    Like this kind of gun BB! Looking forward to the rest of the series!

  4. Thanks, Siraniko and B.B. After installing the peep sight, I set about sighting in. I have never used a peep sight, but having read B.B. and others extolling its virtues, I was excited to give it a try. My first observation was that the target seemed way smaller through the peep than just looking at the target with the regular open sights. Is that an optical illusion? Is there any way to get the target to look bigger through the peep? Would reading glasses or bifocals help? The target also looked dimmer through the peep. Is that normal? My target area is well-lit with a 100 watt equivalent LED bulb hanging in front of it about 6 feet away. I was able to aim fine, but I really had to concentrate on the spot where the now-miniscule front sight touched the bottom of the now-miniscule bullseye. Additionally, I found that my non-dominant left eye seemed to be fighting my right eye, and my sight picture was wandering down and to the right. It was strange that the sight picture stayed exactly the same but was seeming to drift down and to the right. I planted a big fingerprint on my left eyeglass lens in front of my left pupil and that seemed to solve that problem. Another curious observation is that I think I was seeing everything in my line of sight in focus at the same time. For example, it seemed like there was a dirty lens in the sight, but of course I knew the peep is just a tiny hole. So I think I was seeing imperfections or lint on my own glasses, and I could also see my floaters from being severely nearsighted. I have learned to ignore them so completely over the years but they were on full display through that peep! One was right on the bull for a while. Is all of the above normal, too?

    Thankfully, I had put in a lot of trigger time with the open sights and had improved my hold and trigger control over this gun, and I posted my best group with this little rifle with the peep, otherwise I think I would have concluded that peeps are not right for me with my extreme myopia compounded with presbyopia. But I am enjoying this little adventure. Any insights regarding my experiences would be greatly appreciated.

    • Roamin,

      You are keeping both eyes open and that is important. Maybe cover your left eye, but leave it opewn so the right eye passes all the light it can.

      Also, get the sighting eye as close to the peephole as possible. That improves the light through the hole.


      • Thanks so much for the advice. I was trying to get the rubber eye cup touching on my glasses without putting too much pressure on the stock. But the image through the peep was still dimmer and seemed way smaller than without the peep. I might try with contact lenses or with an old pair of glasses to see if that helps or not. Good to know my experience is not unexpected.

        I forgot to report that I also observed the field of view through the peep fluctuating bigger and smaller, but I think that was from my own iris getting bigger and smaller depending on whether I was winking my left eye or moving around on the stock to get a view of the target.

        If I keep the peep sight on, should I get screws to fill the empty screw-holes from the removed rear open sight and scope stop? If so, where do I get those? I doubt they would have anything at Lowes….a gunsmith perhaps.

        I have to say, having shot regular iron sights my whole life, shooting a peep is like magic. You simply focus on the front sight and your target and the rest of the alignment happens automatically. It really doesn’t seem to matter if the bullseye is slightly off center in your sight picture. You just have to intently focus on the front sight, stick it right under the bullseye for a six o’clock hold, and let the magic happen. So cool.

        Next I want to try to mount this peep on my R7 and try the front aperature insert. The prior owner used the insert that looks like a bead on a thin post, but that’s probably more suited to hunting and plinking than to target practice.

        Sigh…this beats working, but I gotta get back to the salt mines…. Have a great weekend everyone!

        • Roamin,
          Should you get screws to fill those holes? Probably. Do I or does anyone else? A few do but mostly not.

          Magic is ideed what the peep sight is. And once you discover it, nothing else satisfies.


        • Roamin Greco,

          Shoot some more with your peep and then read the blogs and replies on THE BELOVED PEEPS once more at least; they will mean so much more to you this time through. FOCUS on the adjustable Iris accessory discussions as well as the CLEAR Front Globe sight insert discussions. A perfect sized to your target BULL front sight insert will cause a thin sliver of light ring to form around the Bull. If you hold that light ring steady you will shoot nothing but 10s and bunch of Xs!


          • Shootski, thanks. I should have thought to search the blog first, and I would have found a ton of info on peeps, and answers to most of my questions. I still have not read everything I found yet, which says a lot about the depth of the combined knowledge of the members of this blog, but I have read enough to know I’m on the right track. I will look into finding a clear front sight insert that will fit my R7 front sight when I go to put a peep sight on that rifle. And I am considering a better quality peep sight with an adjustable aperature for it, too. For now, the cheap peep sight I have is on the Embark, and I don’t think it would be easy to change the post front sight.
            My dream is to shoot all x’s and 10’s! Practice practice practice!

        • Roamin

          I enjoyed reading your comments as a first timer using peeps. Until your obvious success I was wondering, like you, if your eyes were suited for peeps. They are indeed magic. It has been reported here several times that peep sights with a preferred front delivers accuracy as well as a scope out to 25 yards or so. They do for me unless light conditions or the target are not ideal. Sight picture works best for me. Like a few other folks my eyes can even benefit from a peep on a pistol due to front sight focus enhancement.

          Happy you are pleased!


        • RG,

          Wear a hat, head band, whatever to hold a piece of white paper over your left eye. The white paper will reflect light into your eye and help lighten your target along with blocking it’s view from confusing the brain. Take off the rubber eyecup. It works with some and doesn’t with others.

          You will be surprised by how much recoil the R7 has. You will need more than just clamping force to hold that peep on with.

          • Thank you, RidgeRunner. I will try those things. Hopefully, I can train my left eye and brain not to fight my right eye, because I like to have my peripheral vision, especially when shooting outside. I have found that a stragically placed fingerprint or piece of Scotch Magic Tape on my left lens of my eyeglasses (non-dominant eye) has a similar effect, but still provides some peripheral vision. When I was younger, I never had this problem, but I have done very little shooting for about 25 years.
            Now that I am getting back into shooting, I find my eyes doing strange things. Hopefully with practice my brain will sort it out.

          • Gunfun1, I can see how that would be true. I guess I will have to become proficient in all types of sights to see what works best for my eyes. Based on comments above, over the weekend, I started researching this blog for B.B.’s reports on peep sights and the ensuing comments. What a treasure trove of information! I may have to look into an adjustable peep or something a bit more refined than what I have now. However, I’ll play around with this setup for a while until I master it. Right now most of my shooting is from a bench rest, but I want to become proficient at offhand and various positions. No better way to practice than with airguns. I have shot more in the last several weeks than I think I ever have in my life, so I am definitely starting down this path. Actually, it seems as though I am following in your footsteps based on some of your comments regarding peep sights from about a year ago, floaters and all. Thanks again.

    • RG,
      For target shooting I use peep/aperture/dioptre sights. I bought some cheap 1970’s Unbranded Anschutz and never looked back. They are amazing.
      I set them up for the range I use which is about 25m and do well enough to keep me happy.
      For stalking dinner long range I use the scope. ( A grey smudge on a brown smudgy back ground is not going to work with peep sights, with my vision .)

      What I found :
      Slide then back as far as you can, get your eye ball pretty darn close to the hole. Maybe try without glasses. Try not to strain forward to use them. What stance do you prefer?
      The hole increases “depth of field”, everything from the sight to the target can pop into focus. I could not use open sights due to the blurries but peep fixed that.
      If you look with both eyes the hole seems to expand, if you close your off eye it shrinks.
      No idea which is better. Though both eyes open reduces strain. Cover your off eye.
      I can shoot 30 rounds in quick succession accuratly but my eyes WILL wonk out. They will wander and do weird stuff. Pause. Relax. look around. Try again. It is normal. Eyes are weird.
      Shooting with a post foresight is not that easy, a real globe with a round insert is best, however once you get the hang of your sight picture, with the post, it’s pretty darn good.
      Yes the floaters will be in focus and they can float into view anytime. just be patient.
      Weird things in view: I have a hole in my eyeball, it was drilled by the doc to remove rusting steel, this hole makes the peep look like it has a tiny curly pig tail in the hole. It’s in my eye not the peep! No amount of cleaning will make it go away. Hot spark of steel bounced inside my safety glasses and into my eye. Darn…. you only get two eyes!
      I have noticed in my use of the peep that I do this process, 1) look through the peep and centre the foresight. 2) move onto the target without moving my head away from the sight. Now I do it automatically and do quiet well. I do not look at the target and shimmy around to get the foresight in the centre.
      Centre the sights, place on target, shoot. imho.
      Light, you should have a bright target AND background, you need to see all of the inside of the peep hole. If you cannot see this then you will have issues centering the sights. If you have small lit target and dark background then you cannot see the edges of the peep hole. In the pic you can see two sight pictures, A is the bad one. B is the good one. If the background in A was any darker you would have a hard time centering the post properly. This also works for globes. Also make your life easier: shoot at one single target on a clean background. Multiple targets tire your eyes out fast. The perfect target is a large well lit white area with a small dark dot. At 5m indoor I shoot at a 10mm red dot on A4. With practice you can add more dots to the sheet. but the single dot is best!
      In time shooting a peep is as natural as looking at the target, you can practice this all day long without shooting: bring up sight to eye, sight at a dot on a wall, look away, do it again. I do this now and then to keep my eye in, it’s quick easy and no need to shoot.
      Sorry about the novel! : – ) Robert.

  5. B B,
    I’m one of of a very small bunch who prefer the 3 ball sear trigger to the Rekord. Objectively speaking, its technically inferior, but it has a unique feel and breaks like the proverbial glass rod.
    I have many guns with the 3 ball and no matter how the triggers are set upon purchase, I immediately get along with them.
    I was lucky enough to pick up a Diopter 60 today and wasted no time putting it on a Model 35 for a wee session after work. The combination worked very well against metal silhouettes at 15 metres from the get go.

    Regards ,

  6. Well, so much for that dream.

    Once upon a time I was going to buy a Brocock Compatto. They were kind of expensive, but I had finally saved up enough to get one. Then the price jumped to $1000. I think now the price is up around $1400.

    Wait a minute. I have not seen or read any reviews that put the Compatto in that category. The $700 was stretching it. As for the rest of the Brocock line, are you kidding me? Yes, they are owned by the same company that owns Daystate and yes, they are built in the same factory as Daystate, but they are not Daystate. At these prices I expect 1 MOA at 100 yards. You are not likely going to get that with a Brocock, much less a Compatto.

    In recent years there have been a lot of very expensive airguns come on the market. I have been privileged to have shot some of them. I have not been impressed with them. You do not need to spend that kind of money to get a nice airgun.

    Right now I am looking for a nice, light, affordable PCP that I can tinker with a little bit and turn into an air rifle that many will envy. I think I have found it and thanks to GunFun1 I was able to pick up a new one for less than $150. It is the Maximus. I have seen what can be done with a Discovery. I do believe I can make this into a shooter that will turn heads. Let the adventure begin!

    • RidgeRunner,

      But what are you going to DO with it?
      What is/will be the Main Purpose of the airgun?
      What caliber and weight projectile?
      Price of total project at RETAIL?


      • Shootski,

        The main purpose of this PCP will be to tinker and experiment with. So far I have installed a silencer, adjustable hammer spring, nine shot magazine and tinkered with the trigger assembly some.

        I am planning on adding side mounted bipod legs, regulator and shortening it to a carbine. I will lose some power, but that will be OK. I will also likely get a long barrel for when I want extra power and range. I will also tinker around with the trigger assembly more and see if I can improve it a bit more. Everybody keeps telling me to install a Marauder trigger, but I really do not wish to do that.

        Price of total project at RETAIL? Who cares. I am having fun with it.

        It is .22 by the way.

    • RR
      Glad you posted. I was thinking about your Maximus while I was shooting my now Huma regulated Maximus I just got a little while back.

      I knew you was concerned before you got it that it would leak. How’s it been doing?

  7. GF1,

    You ask for some accuracy tests from my low pressure pellet gun. I shot two sets of targets at 10 and 25 yards. I used the AA Falcon 13.43 gr domed pellets and the JSB 15.89 gr domed pellets. This will be a good base accuracy test for when I start to build the gun for accuracy. The accuracy was not anything special and I expect I could improve it by removing quite a bit of slop from the barrel.
    Another issue is my valve started leaking out the barrel a little after I destroyed the seal testing for the fastest valve opening. I also replaced the spring holding the barrel onto the probe with a bolt handle against a simple cam. The spring was more accurate but a little harder to operate and load pellets so I changed the spring to the bolt to make it easier for the velocity testing.

    This version of the gun with the probe transfer port is now finished. I have started building a new valve seat that will allow the new Lothar-Walther barrels to seal directly against the face of the transfer port like a break barrel. They will have a 0.63 outside diameter. The barrel order is a little different or I went about it wrong. I put three barrels in my shopping cart but there was no option to buy. I goes in to “request a quote” and I have not heard back yet. Maybe Monday they will get back to me so I can purchase the barrels.

    I want to install the L/W barrels in a tight barrel band system that I can adjust for horizontal and vertical with set screws like a scope. Then I want to build a latch type clamp to hold the barrel against the seal. The barrel will still slide forward to load a pellet.


      • GF1,

        Did you see the post from BB asking for input for a guy from India asking about spare parts for a M-rod? I made a comment. I figure if anyone would have good suggestions, it would be you.


        • Chris
          I seen you posted a reply and it looks like you covered it pretty good so I didn’t respond because I don’t have anything else to add to your comment.

    • Don,

      All considered,… that is pretty darn respectable given what it is and where it is at in it’s development!!! At least it was not 12″+ at 25 yards. I would say that you are well on your way. Keep up the awesome R+D! 🙂


  8. Everyone,

    There is a guy from India asking me what the essentiual spares should be for a Benjamion Marauder. I don’t know. So I’m putting this question out there to everyone, so you guys can have a crack at it.

    Dear Mr Gaylord,
    Whereas mrod owners in America do not face any problems getting parts,spares etc for their guns,it isnt the same here.Absolutely nothing is avbl.
    Now that you have helped me tune my wpn,it would be prudent to keep a stock of essential parts/ spares so that i can keep shooting.My daughter comes here once a year and her next visit hopefully would be in coming December.
    You have decades of experience on guns ,hence can you please advise me on whatall i should ask her to get from PA and elsewhere.I will be obliged sir
    Best Wishesand Regards
    PS the 1/2 inch gps are now getting a bit boring!!!

    I haven’t got a clue what the esserntial spares should be for the Marauder. I keep mine filled with air and 5 years later it’s still hol;ding fine.

    So I’m posting your question on my blog and letting some of my readers have a go at it.


    • Ranjit,

      Hopefully more people will add comments.

      – The fill nipple would be one item. Always nice to have a spare.

      – There is a common part in the trigger group that breaks on some, but I do not know the specifics. So that part, or the group might be good.

      – Some guns have a complete O-ring kit you can buy. Maybe nice if doing a complete tear down.

      – The breech o-ring is a common wear item. That is what seals the probe.

      You may never need any of this. O-rings may be able to be sourced locally. O-ring type/material matters. Pure silicone oil is always good to have when you have PCP’s. Whatever you are using to fill with,…I might be (more) concerned with spare parts for that.

      Best wishes,….. Chris

    • Ranjit,

      The fill nipple assembly has a sintered metal filter in my Marauder that would be an item hard to source locally so Chris USA’s idea is a good one. If a part in the trigger group failed you would be out of any shooting until replaced or repaired. The trigger Link an the actual trigger (you touch with your finger) is a part that I have heard complaints of failure. A robust rifle so other than a compete spare rifle to swap out hard to say more items that logically don’t have local work around likely to be available until your daugter’s next parts run..


  9. I am going to start posting rifles for Sale in NZ that I think are interesting, and to start the ball rolling:


    and then:


    There is a shed load of Crosman’s going but not my bag. : – ) and other good buys, and there is a 1377 that I may keep and eye on to turn into a 10m indoor …. will watch the auction. Robert.

    • RobertA,

      I would strongly advise you to get that Diana 34 if that is reasonable. You will not go wrong with it. It is an oldie, but goodie. I wish I could get my hands on it. It would be quite happy here at RRHFWA.

  10. B.B.,
    That rifle is a beauty; great for you!
    And I would like to thank you for the book, “BB Guns Remembered;” it was a great read (and I highly recommend it to anyone who has not yet read it); I could have finished it quickly; but I kept it by my bedside, and sipped it like a fine wine, only reading a section as a needed a pick-me-up.
    Also, thank you for recommending Ballistol; had you not mentioned it on this blog, I might never have known about it; it’s fantastic! I use it for all my airguns, and firearms as well; I haven’t yet started drinking it with my coffee…but I may…perhaps it will lube up the old joints! =>
    Take care & God bless,

    • Dave,

      I keep a copy of that book in the bathroom and read it every 6 months, or so.

      I’ve started work on a similar book and have a couple chapters completed. It keeps me entertained.


  11. Happy Father’s Day to all!
    I’ve been thinking about making this comment for a few months; but I thought you all might be like, “Hey, Dave, we already know that…known it for like 50 years…tell us something we don’t know.”
    Hence, for all you craftsmen and machinists for whom this is “old hat,” I apologize in advance.
    I call this technique, “how to sight in your non-click-adjustable sight in one adjustment.”
    This works well on guns like the Webley Tempest, or on guns like my old Sheridan C-model with its factory (but made by Williams) rear peep sight, which slides for windage, and has some lines on it, but no “clicks.”
    The first step is to shoot the gun, get a good group, and see how far off the center of the group is from the center of the target. I’m no artist, but I hope this pic conveys that this Sheridan is shooting an inch to the left at 15 yards. So, we have to move the sight to the right…but how much?

    • OK; by the law of similar triangles, we know that “x” is to the 20″ sight radius as 1 inch is the the 15 yard range; but we have to convert yards to inches, in order to get a meaningful “x” in inches. 15 yards is 540 inches. So x over 20 is equal to 1″ divided by 540 inches; hence, x = 0.037″

      • I got a bit ahead of myself there; on the paper you will see that I have 0.125″ which is the distance from the edge of the rear sight to the edge of the moveable center eyepiece. After that I added the 0.037″, but I broke it up into 0.025″ and 0.012″. That’s because I have a non-dial caliper. 46 years ago, when I started my first job, and I was looking through the catalogue for a a caliper, a crafty old machinist said, “Hey kid, but the one WITHOUT the dial…that way no one will ever steal it off your desk.” (by the way, he was right; people would come by my desk, pick up my caliper, say, “Hey! Where’s the dial?!?”, then throw them down in disgust and walk away…hence, I still have them all these many years later. =>) So, with a caliper like this, each mark is 0.025″ and you have to interpolate to determine down to the nearest thousandth. So, I took the measurement I made of 0.125″ for the current sight setting, then added one more mark of 0.025″ and then another 12 thousandths on top of that; I set the caliper to 0.162″ and then locked it there; then I loosened the rear sight, and used the caliper to push it the extra 0.037″ to the right that it needed to go, and then I locked the rear sight back in place.

        • That’s all well and good…but did it work?
          Yes, as you can see by the targets, it worked very well.
          However, as noted, it will not work on every gun. On my Henry H001 .22LR lever action there is no good point to get a reading with the caliper; hence, I had to use a brass drift and knock it back and forth several times till I got it dialed in; that took MUCH more time than the Sheridan, which was a nice easy “one-adjustment-sight-in”…I love it when things are easy…which they so rarely are! =>
          Happy shooting to all!

          • I love that post, Davemyster.
            I may turn that into a word problem for my daughters who question why they have to learn algebra! What type of caliper would be recommended for a shooting tool kit? I have seen quite a range of prices but the specs don’t seem to be much different. Can you do the sight in operation with a digital caliper?

          • 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!

  12. Happy Fathers Day!

    I feel blessed to have had the one I had
    and for as long as I had him.
    I feel blessed to be a Dad
    and hope to be better at being one every day.
    I feel doubly blessed to be a Granddad
    and I know i’m perfect at that!

    Play more!


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