BB’s Goldie is a golden Cerakoted Avenger. It’s one of my most accurate air rifles, so I chose it for this test.
This report covers:
- Simple and complex
- The test
- Six-power group
- Why did this happen?
- 12-power group
- I saw it
- Teaching point 1
- Teaching point 2
- However
- Summary
I will open with the results of today’s test summed up in two words — holy moly!
Simple and complex
Remember what we are testing. We want to see whether adjusting the magnification of a second focal plane (SFP) scope has any affect on where the pellets go. Today I’m shooting Goldie with the Meopta 3-15X50 RD MeoSport SFP scope that is already sighted in at 25 yards.
Today’s test sounds very simple — shoot one 10-shot group at a target with the scope set on 6 power; shoot a second 10-shot group at a different target with the scope set on 12 power. It sounds so simple. It was anything but!
The test
Today’s test was one suggested by Machiavelli, excuse me, by reader pacoinohio. He said,
“A suggestion for scope testing- (1)- two targets, two groups. One group at 2x and the other at 12x. One shot at 2x and then crank it up to 12x for shot two on the second bull. Repeat until you have two ten shot groups.
Sounds simple, right? Well, it isn’t! I first put 10 pellets into each of two piles. Didn’t want to shortchange any group! Then I realized that I had to separate the pellet piles so I didn’t double dip as I was shooting. So the 6X pellet pile went on the left and the 12X pellet pile went on the right side of my shooting bench.
I also separated the targets the same left and right as you will see in a bit. But it doesn’t end there. Remember, I had my cataracts removed and I can no longer see up close. I had to put on my glasses for each change of scope power. I wanted this test to be as precise as possible.
I shot 10-shot groups from 25 yards with the rifle resting on the sandbag. I used the most accurate pellet for Goldie which we learned in Part 5 of BB’s Goldie is the JSB Exact Jumbo Monster Redesigned. After each shot I changed the magnification of the scope and switched to the other target.
In Part 5 of BB’s Goldie the rifle put 10 Monster Redesigned pellets into a 0.154-inch group at 25 yards. I figured that with all the switching around today’s groups would be a trifle larger, but I had no idea of what was in store!
Six-power group
It took me the entire test to shoot this group because every other shot was taken at 12 power at a different target. The first two shots at 6 power went into nearly the same hole and I was off to the races. Shot three opened the group slightly, but as the test progressed the group kept getting larger for a valid reason that I will share in a moment.
At the end of the six-power test Goldie had put 10 Monster Redesigned pellets into 0.795-inches to my utter shame. One lone shot opened the group that big, but the remaining 9 are in 0.431-inches. While that is better, Goldie is capable of so much more!
With the scope set on 6 power Goldie put 10 JSB Exact Jumbo Monster Redesigned pellets into 0.795-inches at 25 yards. Nine pellets are in 0.431-inches.
Why did this happen?
Remember Part 2 of Rifle stocks? Remember the discussion we’ve been having on cheek weld? When I looked through the Meopta scope for the first shot in this test, the image was dark around the edges. I didn’t have the scope positioned correctly for my sighting eye! Oh, oh. Bad BB!
I could have stopped the test and repositioned the scope, but I didn’t. However (yep — there’s a however coming) when I switched to 12 power on the scope I saw on shot number three (which was the 6th shot of the test) that my cheek weld did matter. I’ll cover that in the discussion of the next group.
12-power group
The first shot on the 12-power target struck the target paper almost one inch lower and away from where the first shot at 6-power hit. I was amazed. Apparently the guys who say changing the magnification on an SFP scope were correct. It makes a HUGE difference? And when the second pellet landed in almost the same place, I was nearly convinced. But the third shot hit much higher. It hit almost where the 6-power pellets were hitting, but just a little lower. The next two pellets went into this higher hole and I thought, okay, that’s in nearly the same place as the 6-power pellets. Then I saw it.
I saw it
Two groups were forming, one low and the other high. That is indicative of an inconsistent cheek weld. The lessons of all I have written on rifle stocks in the past month were coming back to slap me in the face!
There were now 5 shots in this group and 11 shots in the test — the halfway point. And the main group was forming higher on the target — almost as high as the 6-power group. But the 6th shot in this 12-power group hit down low with the first two shots, giving me two groups with three shots each in this 12-power group.
Do you begin to see how complex this test is? I watched the two target groups form and even I was confused!
When I finished, the 10 shots at 12 power had grouped in 0.654-inches between centers at 25 yards. It’s much larger than BB’s Goldie should shoot.
BB’s Goldie put 10 Monster Redesigned pellets into a 0.654-inch group at 25 yards. This group looks like one homogenous group, but until the last two shots, it was two separate groups, a small one down low and a larger one up high.
Teaching point 1
I shouldn’t have to say it but this test makes it clear that your cheek weld is extremely important to accuracy. And if some readers want to call that consistency, I won’t argue the point.
Teaching point 2
But there is more. After the test when I photographed the targets I noticed that the 6-power group was slightly higher on its target than the group shot at 12 power. So I took another picture to show you. I marked each group where I thought the center was, then I drew two lines between the groups to show the height of the group centers on the target. Let’s look at that picture now and you’ll see what I mean.
Here are the two groups as they were shot. The group shot at 6 power is on the left. The two lines are drawn from where I estimated the centers of the two groups to be.The higher line comes from the center of the 6-power group.
The photo above shows us something of interest. It shows that the center of the group shot on 6 power is slightly higher on the paper than the center of the group shot on 12 power. There is a lot of guessing in all of this. For example, how far down does that single shot in the 6-power group drag the center of the entire group?
The way I have marked it, the center of the 6-power group is about 3/16-inch (4.67mm) higher than the center of the group shot on 12 power. With all the guessing can anything be said about these two groups? I believe it can.
You may not agree with where I marked the group centers but it’s obvious the group on the left is higher than the group on the right.
However
Does this test prove anything? Probably not. One group at each magnification isn’t conclusive. But it is an indication that adjusting the power in an SFP scope does change the point of impact. And guess what. We will see this test again. Next time I will adjust the mounting of the Meopta scope until I have it adjusted correctly for my cheek weld on Goldie and I’ll run this same test a second time.
Since I need to remount this scope anyway my plan is to conduct the test of the first focal plane (FFP) Integrix scope next and then come back to this one after that. That way we will get a chance to look at how much a proper cheek weld really affects things. And of course I’m going to mount the Integrix scope so my cheek weld isn’t an issue with it.
One last thing. What does adjusting the scope between shots prove? Nothing, I think. I want to shoot all 10 shots at one power and then all 10 shots at the second power. That gives me, the shooter, a chance to settle down with a single sight picture for each group. I do think doing it the other way was why today’s groups were so large. Since I plan to re-test with the Meopta scope anyway this shouldn’t prove to be a problem.
Summary
This is an interesting test, but we are far from finished. So hold your final opinions until all the data are in. Oh, and — holy moly!
BB,
This is a most interesting set of results; yet I think that your idea of “all ten shots at one power and then all ten shots at the second power” is the way to go. Thank you for all the work you are putting in…I wouldn’t have the patience!
Blessings to you,
dave
I wonder if the SSP in the title really means something that I can’t think of.
Other than FFP that is…
Bill,
I believe B.B. didn’t wear his correct glasses when he typed that…Lol. 2nd Focal Plane or is that rain on the plain or just the pain of a Mirage?
shootski
shootski,
In Spain! In Spain! ;^)
Michael
Bill,
It means that BB didn’t catch it. Thanks,
BB
B.B.,
If’n you changed glasses each time are you certain you put them on the exact same each time? A very similar result of another lens moving just like what happens when the eye a lens is not in the same place in the scopes eyebox due to cheek weld displacement.
I believe the future tests should be done as you stated; ten at a time the reset power. Testing needs to exclude variables to avoid inadvertent contamination of test results. But you know that from your OT&E days.
shootski
Shootski
Recently folks have commented about the virtues of shooting with variable magnification lens glasses and how the brain sorts things out after getting used to these glasses. I wondered if you or someone would question their use with scopes. It has been years since I gave up wearing variable lens and technology may have changed.
BB is concerned about cheek weld shooting from a bag. Maybe so but switching those glasses on and off every shot may be the major human variable in his test today.
This is my not worth two cents analysis.
Deck
Decksniper,
I think you are on to something.
What exactly is Tom testing? If he mounted both scopes on a fixture and aimed them at a set of Test Targets at a set of surveyed distances it would be a test of the scopes Sight Line at various settings. An assistant with a marker would be used to mark the targets on direction(s) by Tom.
The result would then be a slightly “cleaner” comparison test of the two optical sighting systems at various settings.
There would actually be little indirect value (is cheap worse than expensive) of the testing to consumers due to the small sample numbers tested as well as numbers of trials not to mention the non usage of Blind Testing protocols.
And, now for the downside:
We would never have B.B. get to do anything else for months!
shootski
Decksniper,
I have been using my first set of Progressive Eyeglasses for the past month. As background i had Cataract Surgery on my left eye at the end of December 2022 and took a bit of time to allow my vision to stabilize. In my Left eye i only needed reading distance correction. My right eye acuity seemingly didn’t change…or did it? I have an appointment with my Opthalmologist on Monday morning to discuss what the left eye to brain connection and right eye looking through Progressive Eyeglasses is or int doing for my vision in general but specifically for shooting. We had a brief but wide ranging discussion in a recent telephone conversation about where to start her research and the specifics.
I don’t think Progressive Lenses are ideal for shooting. I am beginning to believe that naked eye is best and that no lens outside of the scopes should be used for best results. Shooting safety glasses/goggles need to be used and be as perfectly neutral optically as posible when used.
I will know much more after Monday.
shootski
Shootski
Hoping you and your doctor get it worked out to your satisfaction. Let us know whether or not you choose to look through a scope with these eyeglasses. Except when shooting firearms I let my prescription eyeglasses serve as eye protection when shooting. Probably not wise but they are bifocals and convenient for loading. I don’t like wearing two pairs together if I can avoid it. I have trouble reading slope on golf greens wearing sun shades over eyeglasses. I do better just wearing non prescription sun shades.
Deck
I also use my glasses as eye pro, however, you do lose the side protection if your glasses don’t wrap around like true safety glasses would. Also to mention to other readers, not all eyeglasses will protect well from a projectile. See the last scene in “A Christmas Story.” My glasses are polycarbonate and thick due to severe myopia. Your milage may vary, so don’t shoot your eye out!
Shootski, I will be very curious as to what you learn. I saw my ophthalmologist in Church yesterday and got his email so I could sent him Friday’s blog in advance of making an appointment with him. I need to replace these single-focus glasses with something that will address my myopia and presbyopia and still allow me to shoot.
Roamin Greco,
I think i can provide a hint. It might be a contact lens trial of some sort was the drift in the telephone conversation. It will no doubt include another round of extensive testing with all manner of new testing equipment and eyeball imaging machines and consultations with other more Senior Opthalmologists in the Department. My current doctor is the current Senior Resident (my previous doctor is doing a Permanent Change of Station and recommended this particular eye doctor) so up on all the latest education and has a bit more experience than an intern.
I’m staying open to all ideas.
shootski
shootski,
I have not thought of this before, but it seems either the naked eye or the eyeglass lens is an additional focal plane. So with glasses it could be technically thought of as a two-focal plane and three focal plane arrangement? Aaaagh!
Michael
Michael,
Makes you wonder how anyone can hit anything!
shootski
I suppose a really intense testing regimen would include more targets, at different magnifications, at different ranges. Try an airgun at 10 yards at 2x, and 50 yards at say, 8x and 12x.
Or just carry it at lowest power for quick shots, and adjust up only if you have time.
Honestly, rather than measuring group size, I’d rather see impacts on game/varmint targets, or paddles for our Field Target friends.
Plinker,
2X is too small for much precision. That’s why I didn’t use it.
BB
B.B.
I would think lesser scopes may not do so well….. Also, will a 50 yard shot that requires 4 hash marks hold overs at 10X, require only 2 hash mark holdovers at 50 yards at 5X?
-Y
Yogi,
I guess you’d have to test everything to know.
BB
lesser scopes? just think with that expensive scope BB is using on a target cartridge rifle switching powers at 800 -1000 yds. the difference in impact might be measured in feet
BB-
Well, first off- You’re Welcome! You had asked for testing ideas so that you didn’t have to return the Integrix scope right away. Sooooo……. Mission Accomplished!
Second, kudos for letting us know that even former officers can learn their left from their right without being all bragadocio about it. 😉
Though you didn’t mention it, there does seem to be a left/right shift between the two groups. I wonder if that would be more apparent if tested at the magnification min and max stops- 3x and 15x?
I think today’s test was more about the final tweaks needed when mounting any scope for optimum sight alignment- full reticle picture with proper cheek weld across the magnification range.
Paco,
As far as the left-right shift, it might be there but the two groups are too large to tell for sure.
Remember, the Integrix tops out at 12X.
As for the proper scope positioning — that’s a pie in my face! 🙂
BB
BB-
My 3x to 15x comment was in reference to today’s Meopta scope. The Integrix test would be 2x and 12x.
Group size is not particularly relevant. We pattern shotguns, not just for size and density, but also in relation to aim point. Same with today’s two groups. Left and right shot extremes for each group- strike a vertical line down the middle- measure distance to aim point. Should tell whether there is a left-right bias.
BB,
WARNING! The following is my unprofessional opinion.
I know I myself have no proof that changing power causes impact shift, but this possibility is one of the reasons I do not do such with my scopes. In my sixty plus years of shooting, I have always left my scopes set at the maximum power. When shooting target or long range hunting, I do like to use higher powered scopes and those airguns are equipped accordingly. As an aside, 18X is a HUGE powered scope for me.
When I am plinking or woods hunting, I prefer lower powered scopes, if I use a scope at all. A fuzzy-tailed tree rat up in a tree can be hard to find in a scope. Around 6X works well for hunting small, furry, woodland creatures at fifty yards or less.
These days it has become difficult to find good quality scopes at reasonable prices, period. To find a low powered good quality scope at a reasonable price is very difficult indeed. Fixed powered scopes are very difficult to find, at any price. IMMHO, many of the scope manufacturers have entered into the power race. The apparent impact point shift with the power shift is an issue that will likely always haunt the optical world. The first focal plane scopes MAY be the cure for such. We shall see.
Another issue with scope construction is the windage and elevation adjustments. The infamous “box” test is often used to determine the preciseness of these adjustments on particular scopes. This particular issue usually only raises its ugly head with low quality scopes.
BB,
Leaving this subject way behind, yesterday afternoon I spent some time on the back porch with my grandson’s HW30S equipped with the TruGlo front globe sight and the Williams rear peep sight. Sitting on the steps and leaning back against the post, it was difficult to miss my 3/8-inch spinner at ten yards. This makes for a very accurate, very quick, close-range shooter.
RR,
I hope so! My old-style HW 30 stock arrived on Saturday and I plan to get it into service soon!
BB
Tom,
Wow. He works quickly.
Michael
Tom,
RidgeRunner explained above that (and why) he sometimes uses / prefers a single power scope to a variable power one that can provide greater maximum magnification. Of course a variable power scope can have its magnification set to its lowest capability, but is there a structural advantage to a simpler, single magnification scope?
Obviously variable power scopes have much more going on in them. Does this make them more fragile than similar price-point, single power scopes? Does this make it less likely than a similar price point but single power scope to hold zero over time and many shots?
If two scopes by the same maker are abiout the same price, but one is single power and the other is variable power, is one probably better?
Michael
Michael,
Wow! Okay, here are my answers. I don’t know. I don’t know I don’t know and I don’t know.
I would THINK that a fixed power scope in more rugged because it is simpler. But I just don’t know.
BB
B.B.,
I know at least one thing!
If you drop them from high enough or bang them against something or someone hard enough they will likely lose ZERO at best or become BROKEN at worst in either case.
shootski
shootski,
Absolutely! And if you shoot them with a .22 caliber rifle bullet the damage will be even worse. 😉
BB
Tom,
I asked because I know almost nothing about scopes but now believe I will be a scope-only air gun shooter. To give you a picture of where I am coming from, in my collection I probably have around 100 air rifles, but not one is scoped. I have always used the iron sights or, in the case of my TX200, have “gone commando” and sighted down the barrel.
A scenario: two AO, 1″ tube scopes by the same maker are virtually the same except one is, say, 6X and the other 3X-9X. One is, say $60, the other $70. Would you expect one or the other to be more likely to survive 2000 shots mounted on a medium power springer? Or would they be probably about the same in that scenario?
Thanks,
Michael
Michael,
In THAT scenario, both would survive equally. Let’s define a medium-powered springer as a Diana 34.
BB
Tom,
Cool. I was going to define medium as an HW50 or HW77, so, (as more and more people are saying these days, but I think it began as a British thing), yeah . . . . :^)
Michael
SFP or FFP matters not one whit in this test. It is purely a matter of tolerances and precision in the construction of the zoom mechanism. The same goes for focus, whether side or AO. I had a scope that would change POI 2″ when focusing between 20 and 50 yards. Yes, a higher end scope should minimize this, but not necessarily.
If the scope was adjusted properly for parallax error then the cheek weld would be irrelevant. There’s something else going on here. Can you shoot without your glasses and adjust the scope to compensate?
That is an interesting point. I have to go back and reread Shootski’s and B.B.’s writings on parallax but I think you are onto something. Makes me tend to agree with Shootski and Decksniper that the glasses could have contributed to the results.
I would also say sometimes one might be surprised how even a pcp’s point of impact might be affected by some inconsistencies in the hold. That certainly can be true with my CO2 guns.
You order a Weihrauch break barrel online, you receive it, and take it out of the box like a kid on a Christmas morning. Then you shoulder it and notice that the comb is too high for your face to use the open sights…
I think, with a little help from the air rifle collectors here, future buyers might be able to avoid this disappointment. How about a quick reference chart using the air rifles that are sold at the big retailers today? That way people can stop by those stores, shoulder those reference air rifles, and know if the quality air rifle that’s sold online will be a good match or not.
Let’s say you hold a mainstream air rifle that’s sold in a discount store, and if you can aim using the oem sights on that rifle, it’ll mean you’ll easily see the sights on HW break barrels as well.
Fish,
Or the kid could hand it to his dad who has a band saw. ;^)
Michael
Everyone,
I wasn’t wearing glasses when I shot. I wore them only yo see the numbers when I changed the power on the scope.
BB
OFF Topic
This is what you get with a ZORAKI HP01-2 Pneumatic Multi Pump Air Pistol ( AKA Webley Standard or Ultra )
Class Act
What, no kitchen sink?
Seriously, that’s a nice bit of kit as our friends across the pond might say.
Roman,
Just remove the foam insert for use as a sink. 🙂
It is a very nice and sturdy, lockable, ATAK ARMS case. Even cut out for a small folding handle, Light or Lazer.
That plastic pouch even has extra, or other, sight blades front and rear. May be used in connection with the optional rifle stock available. Not sure yet.
You may want to remove the grip platform if you have large hands. It may have a technical name? Fits me fine and it appears to help steady the large but reasonably light pistol.
I consider it a Special Airgun compared to most non10-meter types. BB did a blog on the Webley Alecto Ultra version. May be wrong there? AOA definitely did. and it is called a palm shelf. Go figure.
BB did a 4-part blog on the “Webley Alecto” the short barrel version that apparently has a bit less FPS. It was over 12 years ago. The names of the participants have been changed to protect the innocent 🙂
Bob, it looks so cool. You should do a guest blog on. It.
Roman,
You know, I think I would really enjoy that. However, I know myself well enough to know I would never get to finish it. I have three strikes against me.
I am still a perfectionist to some extent and in my need to make things perfect, I am always looking for better options or ways to accomplish something. The more I analyze something the more I options I find to further explore. Then each of them deserves more analysis.
This results in “Analysis Paralysis”. The inability to decide which way to go or settle on.
As a result, I have become an expert at “Procrastination”.
It would take a lot of time I simply do not have caring for a disabled person. I do everything, inside and outside the home. I do this while resting, mostly in bed after the day ends.
Just yesterday I found my 10.000-gal water tank is resting on my water pressure boost pump instead of settling into the pea gravel it sits on. The rigid supply plumbing at the bottom is directly connected to the pump and it sits on a concrete pad. Something is going to give soon. More analyzing.
Bob M,
A rigid metal tank with mostly flat bottom?
If you can’t or won’t empty it you need to “float” the tank higher.
Not knowing the exact setup would digging small radial trenches toward the center of the tank be possible then use bladders/deadheaded firehose that you slip into the trenches and inflate with air and/or water to raise the tank a little at a time pushing more pea gravel under the tank (evenly) at every opportunity?
Remote engineering at its best!
shootski
PS: only 80,000+ pounds to lift ; ^)
Shootski,
Thanks for the suggestion. As you know the pea gravel is there to prevent rain from pooling under it and rusting. It has a steel band surrounding it to prevent it from migrating outward. However, I believe the shaking from numerous small earthquakes and tremors cause it to sink in from the sheer weight displacing it. It’s 12’H x12′ in diameter.
I have a fill pipe, a 4″ fire hydrant supply and float wire conduit to consider also.
I jacked up the pump inlet pipe and knocked out the 2×12 wood plank between the pump and concrete to relieve the pressure but that will only allow the tank to sink easier and faster.
Plan so far, empty, jack up slightly and place bricks and/or concrete around the circumference.
Was not a big problem with the old 3.000-Gal tank. New CA law requires bigger 10,000-Gal one for fire department use. No water supplied out here.
BB
I still think you should use an adjustable, locked in place, rifle or pistol stand to eliminate any human or vision accessory interference, in accuracy testing of any sort. Unless of course you are testing for human interaction itself.
You eliminate any change from cheek weld, eye relief, eye glass distortion, recoil, reloading, repositioning and trigger pull between every shot.
B.B. and Readership,
I use a formula i learned from Dick Thomas (RIP) of Premiere Reticles but:
I have been trying to find this calculator for you all for a few days.
I think you will ALL enjoy it:
https://www.lelandwest.com/parallax-error-calculator.cfm?Action=1&CFID=6442472&CFTOKEN=e290445e2a277dcd-92681825-D4CB-03E4-F5C53644A46DD607&jsessionid=A26BBC0C67CA07F53A4BFD70E210162E.cfusion
shootski
That’s cool. Check it out, the further you get away from the place the scope is set as parallax free, the more parallax you have.
Roamin Greco,
The parallax rate of increase is much steeper inside of 25 yards/meters which if you plot a graph of the formula clearly shows.
That fact of course needs to be of greater concern to airgun and rimfire shooters.
shootski
I’ll have my daughter plug the formula into her graphing calculator and see what happens.
Also,
I decided to start a small experiment this evening.
Remember I am Right handed and Right eye dominant but have trained to shoot both sides and eyes for many years but not much since my Left eye Cataract removal in December.
I shot my SIG .22cal SSG ASP20 WHISKEY3
LEFT (bare left eye and left trigger hand)
on my DOA Bench off my Sinclair Rest and a rear bunny ear heavy bag. So far the results at 90 feet (steel tape muzzle to target face) in failing light are very interesting. I hope to get different light conditions and try to incorporate the progressive eye glasses into the experiment for both sides and eyes.
Much of this is for sharing with my Opthalmologist on next Monday.
FYI The .22 SIG is much easier to get small groups compared to the .177 in my limited gas springer/break barrel experience.
shootski