By B.B. Pelletier
Where to zero a scope is a question that always starts a friendly conversation among airgunners. I’ll tell what your options are and leave the final choice to you.
Pellets start to fall the minute they leave the muzzle
The moment a pellet (or bullet) leaves the muzzle, it begins falling toward the ground. It falls at the same rate it would if you dropped it from the height of the bore – assuming the bore is parallel to the ground! And that’s where the scope adjustment comes in.
Because a scope looks straight out and because it is mounted above the bore, it can only be made to intersect the trajectory of the pellet if it points down through the ballistic path the pellet takes. And, that is how scopes are sighted-in.
They are adjusted to look straight through the downward arcing trajectory of the falling pellet, at a point close to the muzzle. When the pellet arrives at the spot where the downward-looking scope is pointing, the crosshairs will be exactly where the pellet is and the scope will be zeroed at that distance.
Beyond this point, the scope will actually be looking UNDER THE PELLET’S FLIGHT for a certain distance after the first point of intersection. Then the falling pellet will cross back through the scope’s line of sight once more, intersecting the pellet a second time and creating a second zero point.
How we correct the picture!
Nobody likes to think about their pellet falling, so we angle to scope down so the pellet seems to be going slightly up when it leaves the gun. Now, the whole thing makes more sense.
The pellet SEEMS to be rising when, in fact, it is only doing so because the barrel is tilted slightly up at the muzzle, compared to the optical line of the scope. The downward-looking scope intersects the pellet at some distance downrange, then the pellet SEEMS TO RISE above the straight line of the scope and intersect a second time further downrange.
What’s a good distance to sight-in a scope?
Now that we understand how it works, we need to find the right distance to sight-in. You now understand that the scope will actually be zeroed for TWO DISTANCES instead of one.
For a pellet gun that shoots around 800 f.p.s., I like to sight in at 20 yards for the near distance. The second distance will be around 30 yards, and the pellet will not rise by as much as one pellet diameter at the in-between distances (between 20 and 30 yards). If you sight in at 15 yards with the same gun, the pellet will be back to the intersection of the crosshairs around 40 yards, and it will rise more than an inch in between.
For a gun that shoots 950 f.p.s., I would still sight-in at 20 yards as the near distance but the far distance is now 37 yards or so. For both guns (800 and 950), the pellet will be about one inch below the aim point at 10 yards and will rise to the crosshairs as it approaches 20 yards. At the muzzle, the pellet will be as far below the crosshairs as the bore is below the optical path of the scope, which could be as much as three inches or more!
What if I only want ONE sight-in distance?
It IS POSSIBLE to sight a scope to intersect the pellet only once, but why would you want to? You align the scope to graze the pellet’s trajectory, and after that it’s all down hill!
My suggestion for a clickless (or almost holdover) life is to assume a 30Troyer (distance in yards divided by the kill zone in inches) kill zone. This works out to be 1″ at 30 yards, 1/2″ at 15 and 2″ at 60… If you zero at about 3/8″ high at 25 yards (assuming that is the highest point for your pellet) you will be in the kill zone from about 15 to 40 yards. Closer than 15 or farther than 40, aim for the top of the kill zone.
This assumes you are shooting field target with holes, of course. If shooting game, you really won’t be shooting much at the long distances (and wind will have a much larger effect than pellet drop). For short distances, you are probably fine up to about 12 yards but just aim about 1/4″ high if you have the time to setup the shot.
Joe,
Thanks for your input. You have a good plan as long as the kill zone (or traget) is of a known size. But it really goes farther than that.
What Brad Troyer has done is reduce to an easy process or formula the gut instinct a rifleman who knows his gun has for how much aimover to apply. That’s a wonderful way to shoot a gun!
Our readers should study your comments and try to appy them to their own shooting.
Thanks,
B.B.
first question. Does barrel length play a part in this intersection of scope and pellet path?
second question. When I got my rifle to shoot a target 10 feet away it shot to high at 25 feet. Is there a gun that shoot from 5 feet to 25 feet more accurately. and another that shoot more from 25 feet and above?
third would a shorter barrel gun be more effective for closer targets.
Barrel LENGTH doesn’t matter. What matters is velocity, and, depending on the powerplant, barrel length affects velocity. Pneumatics and springers go faster with longer barrels. Springers go a LITTLE slower with longer barrels.
If your gun is sighted to hit dead-on at 10 feet, yes, it will rise at 25 feet. That’s what I was saying in the posting. No gun shoots more accurately at 5 to 25 feet, but if you want a flatter trajectory at that distance, you need a gun that shoots slower.
A shorter barrel will usually be slower, for the reasons mentioned above. I don’t know if that answers your question or not. It sounds to me like you want a good bug-buster airgun, so watch tomorrow’s post.
Thanks,
B.B.
How do you figure out what the two intersections are?
is there a formula
Great question, and one that takes too long to answer here.
Look for the answer in this week’s blog
B.B.
I don’t get it, why don’t you simply sight it in so that the scope is pointed parallel to the bore, but a few centimeters above? In this case you could target shoot, or hunt at all distances, but consider the fact that the scope is a few centimeters above the bore.
That would work well with a laser, but isn’t very useful for pellets for the reasons the original post explained. The pellet travels in an ARC toward the earth but the scope is a perfectly FLAT line of sight.The farther out you are shooting the more drastically the pellet falls below your line of sight (or point of aim) causing your point of impact to be WELL BELOW your original few centimeters of difference. If you adjust the ARC to INTERSECT the FLAT line of sight in TWO places you extend your effective range before it falls too far to below the line of sight to be seen in the view of the scope. The best method is to let it intersect the line of sight at a closer distance (1st) while not rising too far above the flat line before coming back down to the farther (2nd) intersection point.
I hope that helps.
Sounds like time to post some links to good ballistics software.
Chairgun is an excellent choice — it used to be free but the current price is very reasonable and the program is worth every Pound (the author is a Brit and uses the monies for charitable purposes).
As originally posted, the instant the pellet leaves the barrel it starts to fall and slow down. Hence, it is impossible to have a gun that hits the same spot at any distance without adjusting for this curve (trajectory). Higher sighting (scopes, red dots, etc.) make it worse, not better.
You can learn to holdover or “click” (use the elevation knob on a scope) but if you shoot at distances from 5 yards to 50 yards, you must learn your gun’s ballistics!
Best,
Joe
Joe,
Thanks for the link and for taking the time to help out.
B.B.
Are adjustable rings recommended for mounting a scope?
I like them after they’re on the gun, but they are twice as hard to set up.
Maybe I’ll do a post about them.
B.B.
I have to help a friend sight in his chinese air rifle b21 in 22 caliber it was tuned and chrono shows 740 fps 17 ft lbs of energy
this is with a 14.3 gr pellet
at 100 feet it still puts a hole in can the same as it does at 30 feet.
what do you recommend as the two sight points?
we will be using adjustable rings
thanks
I would zero at 20 yards for the near point and see how the far point works out. I’m guessing it will be 27-29 yards.
B.B.
At what distance sholud my first piont of zero be if i am shooting a 1000fps gun?
I just bought a GAMO 220 with scope and I read that I should sight in at 20 yards and 40 yards but how do I do that?
Bob Taylor
Bob,
The two distances are really from the same sight-in. If you do 20, you also get 40.
Your scope looks downward through the trajectory of your pellet. The pellet begins falling to earth the moment it leaves the barrel. The downward curved path it follows is called the trajectory.
A straight sight line that intersects the trajectory at 20 yards, will then drop below the pellet until it has gone 35 to 40 yards, when it will fall down to the sight line again. That’s where the two distances come from.
B.B.
BB
Thank you. So if I understand this process, I shoot the rifle at a target, and adjust the scope, until I can consistently hit the bull’s eye at 20 yards. I then get 40 yards too. What happens if I want to shoot at something that is 50 yards away? Do I just estimate the range and guess for longer shots? My scope is a BSAS4x32 and does not appear to be adjustable except by the two adjusting rings under the caps.(in the middle of the scope) I have never used a scope before so I am really in the dark here.
Thanks for your help
Bob
Bob,
With your kind of scope you estimate and aim over. all shots will be lower than you aim point.
By the way, the second distance may not be 40 yards, but 35 or 37. that is something you’ll have to discover.
Read the past posts on sighting in a scope. There are quite a few.
B.B.
B.B.
OK I am off to the basement to try to get the hang of this. Thanks for your help.
Bob Taylor
Here’s a great site that illustrates this idea of the zero range and the basic concept of pellet trajectory:
http://www.arld1.com/trajectory.html
You can interract with the graphic to see how the scope’s line of sight intersects with the pellet’s fligh path.
Matt
Hey BB,
I’ve been reading alot of the blogs and now have a good idea about the 2 point intersection deal. But what about a parallax adjustible scope. Does this just simply move the two intersection points equally. For ex. If your two intial points of int. are 20 and 37 yards (with the scope parallax at 20 yards) and you adjust the parallax to 30 yards will the two points of int. now be 30 yards and 47 yards. Hopefully this isnt answered in any other blogs or posts previously but i dont think i saw it. If it is just point me to the right blog/post.
Much thanks, Kyle
Kyle,
Parallax correction has nothing to do with trajectory. It only correct parallax of the sight. The trajectory remains the same and the two intersection points stay where the are.
B.B.
having bought an rws 350 and scoping it with the 450 scope i’ve been in left field. Since it is winter-feb07-I’ve been reading as much as as I can about airguns between trips to the range–all of a sudden I can’t get enough-I’ve been bitten hard by the shooting bug! Thanks to your blog I can now properly site my rifle in and have a good idea at what to do when shooting out to 40-50-60 yards-thanks for a great site-sure takes the sting out of those cold days!
Scott298,
This blog is for you.
B.B.
B.B.
First, should I use the winchester 500x for small pests? Second, where should my first point of zero be?
Thanks a lot.
I’m not familiar with the 500X. It isn’t in either the Pyramyd AIR website or the Daisy website.
B.B.
Now I know what a 500X is.
It is WAY TOO underpowered for hunting of any kind, unless you have a .22. Then it’s suitable for mice and very small birds out to 20 yards. As a .177, it’s too weak.
B.B.
B.B.
Thanks a lot for the info on the 500x.
Is there any affordable air rifles that shoot at 500fps or bellow that could be used for pest control/small game.
Many Thanks
500X,
Okay, you are either a Canadian or a European.
Here is how to address the problem. Get a rifle that shootes the largest caliber you can find at or below 500 f.p.s. A .32 caliber rifle would be ideal. But that will cost a bundle.
Have you considered a crossbow?
B.B.
B.B.
Thanks a lot for the info. I was looking for an air rifle, do they make .32 air rifles? Or were you talking about a real fire arm.
Thanks a lot.
Yes, there are .32 caliber big bore air rifles, but they are being custom made. Last night I spoke to Dennis Quackienbush who makes big bores like this.
Dennis says he doesn’t want to make airgns for Canada because of all the restrictions shipping to Canada, so you would have to find a Canadian maker. I’m sorry that I do not know of any big bore airgun makers in Canada.
B.B.
B.B.
Thanks a lot for the info.
Seeing this exchange over this mystical 500fps limit for airguns in Canada/Europe, I am perplexed at the state of affairs their citizens must deal with.
It would appear that common sense is not a part of the equation when it comes to that category of regulations there.
It really is a pity that those regulations weren’t put in place so much to stop guns, as they were to discourage hunting.
I sincerely wish you luck in your search for something that will fit your needs.
-Scott
Helo BB, This is my first foray into “big bore airguns” I am purchasing a rifle that is capable of 470 foot pounds with a 205 grain “bullet”, I have a few questions if i will be working with ranges up to 120 or so yards, what would be a good starting “zero point” so that I get the maximum amount of “leeway” such as the 20 yard inital zero point for a 850fps diablo pellet? The “bullet” I would like to shoot has a ballistic coefficient of .189 which is a bit more than your standard diablo pellet, the rifle in question can shoot the 230 grain “bullet” at around 950 fps. I say aproxiamte because the builder of the rifle at the present did not test a 230grain, but the gun will shoot a 205 grain conical at 1020fps, so by my calculation it should shoot the 230 grain at around 950-980 fps for a final energy of around 500 foot pounds or so. Any help would be appreciated thanks, BTW this blog has a lot of really good info. This blog is responsible for me getting back into airguns again thanks.
hi i was wondering if anyone could help me. i have a gamo cfx and got it zeroed when i bought it. last week a took it apart for a major clean after a hunt (11 rabbits and a pheasent, would have been 12 but the little bugger seen it coming). after taking it apart i have tried to zero it myself but im struggling a bit. i was hoping for some input
you can email me at spitfire.1500@hotmail.co.uk
hope to hear from someone soon
spitfire,
You never have to clean an air rifle unless it looses accuracy.
When you say you took it apart, did you take the action out of the stock or did you disassemble the action? If the latter, you need to send the gun and all extra parts to Gamo U.S.A. for reassembly. And then do ever disassemble it again.
If you didn’t really disassemble the action, what did you disassemble and what seems to be your problem now?
B.B.
the mounts that attach to the sight then attach to the rifle where coming loose because the padding was falling apart. i took off the mounts then put tape round the sight so it would have a better grip.
then when i put the sight back on hte zero was out by a long way.
If the last comment was from spitfire and if you are referring to the disassembly issue with your Gamo CF-X, then I understand that you didn’t disassemble the rifle but simply remounted the scope. No problem there.
Is that correct, and are you spitfire?
I am holding numerous conversations on postings all over this blog, and when I have to answer something specifioc, I have to know who I’m talking to and what we are discussing.
B.B.
Ok..Im new to this air rifle thing, How do you get 2 distances from one scope? and how do i find out the fps of my gun? Ive just got a secondhand Gunpower Stealth. With a simmons deerfield 3x9x50 Scope. Also what is the best kind of range to zero in at? i will be using for vermin hunting mainly
If you Google your question with the words pyramydair blog it should bring you right to where you want to be if you scroll to the top of this forum and start reading the comments and answers and you will get answer that you need basically if you sight in at 20 yards your second site and will be at 40 yards automatically at least within a few yards or so you have to figure that out by shooting your gun at both distances your scope is a straight trajectory and your bullet goes on an arc the scope intersect the bullet’s path at two points that is your answer in simple terms if you need more info refer to above comment
lego-man,
Unfortunately this posting is the place I would have referred you to answer your question about two sight-in points.
Friday’s blog will be devoted to answering your question. I will draw diagrams.
You find out the velocity of your gun (measured in feet per second or meters per second) with a chronograph. Read this article to see how they work:
/article/Who_needs_a_chronograph_August_2006/31
Your Gunpower Stealth airgun is probably 12 foot-pounds. It will shoot a .177 caliber 7.9-grain p[ellet at about 800 f.p.s. or a .22 caliber 14.3-grain Crosman Premier at about 585 f.p.s.
Zero the rifle at 20 yards and the pellet will be on target out to about 25 yards. At all other ranges the pellet will shoot below the aim point.
B.B.
hello, everyone i feel like the stupidest person on earth.i have a crosman 77 elite/ .177 with raptor pellets they say im getting close to 1300 fps. any way my prob, is this. my friend tried to zero in my scope because i never did it before. and now i cant even hit the side of a mountain. any advise as to just getting this scope to a point were i can work with it. thank you for your time ken n.j
Ken,
Read this article, then do exactly what it says. You should be zeroed inside 20 shots.
/article/All_about_scopes_Part_3_April_2005/22
B.B.
I have a laser bore sight. Will this simplify or make it more difficult to zero my scope? How will I use the bore sight?
Spodeboy,
The laser boresight is supposed to simplify sight-in.
Follow the instructions on the package.
B.B.
The package tells me to sight the scope in at 50 yards. That’s too far. I think I’ve worked this out. I used the ChairGun2 software and I think I will sight it in at 20 yards which will also give me zero at 30 yards. Thanks.
Being a teenage around 20 years ago when my father gave me a benjamin with a scope, I faced this zeroing problem with no one to help me that time. I knew that if I zero it at -let’s say- 20 yards, I’d have to aim higher for object closer than that and aim lower for longer target. But to determine how much lower or higher was not easy.
So, I solved this myself (considering that I had no available sources that time to do it ‘right’ and I live in Indonesia) by zeroing the scope to INFINITY.
Yes, this may sound ridiculous. But I want to share it, asking for opinion (especially from you BB), and asking if maybe there is another person who did the same as I did.
Zeroing to infinity is like this: my scope is about 30mm higher than the airgun’s barrel (now a Sharp Innova), so I zeroed mine always 30mm lower than the crosshair, at any range! This way, I can easily shoot any target within range of my airgun (around 25 yards, I assume the bullet has its best flat trajectory).
Well that’s said. I am enjoying rat hunting and ’til now I still do what I ‘invented’ some 20 years ago.
Thanks, Jim.
Jim,
I read your comment and cannot follow you on this infinity zero you talk about. Could you do a guest blog about it and perhaps explain with diagrams?
B.B.
BB, thanks for replying.
http://zeroing-to-infinity.blogspot.com/
I’ve built a blog for it with diagram in in, hope you understand what I am talking about.
So many thanks.
PS: I am really enjoying reading your airgun articles. Thanks a lot for sharing.
Jim.
Jim,
I think I understand, but I’ll continue to read your blog a while before I’m sure I know what you are saying.
B.B.
B.B.,
I’ve ust upload a new diagram. Please refresh it.
Thanks, Jim.
Jim,
Looks great, except pellets don’t shoot flat like you portray in your graphic. They drop fast.
Your system will only work at short range, from what I see.
B.B.
B.B.
Yes I know. I tested it within 20-25 yards. Thanks.
Jim.
Good idea. Aim 30mm high for close range. The further the target, the higher one aims.
This eliminates the “two-point zero” confusion for me, personally.
Joel
I am enjoying reading your blog.
I am thinking of buying an air gun for pigeon and bat control around my home.
1) My typical shot will be at 20 meters at an angle of 35 above horizontal. Would I expect my point of impact to be high with a scope that is zeroed for a 25 meter horizontal shot.
2) Could you recommend a minimum muzzle energy that would deliver a fatal shot to a roosting pigeon (and / or bat) from that distance?
Thanks
Pinche,
Here is how to deal with elevated shots. In your mind, drop a plumb bob from the target and see how far away the bob is when it is level with you. From your description I would guess you are making a 15 meter shot. So sight in for that range.
A gun zeroed for 25 meters will be very low at 15 meters. Depending on the velocity maybe more than one inch/25mm.
Energy for the kill is a lot less than people imagine, if the placement is good. A gun that starts out with 6 foot-pounds can kill a pigeon at 56 yards, as the Urban Hunters proved when they wrote for me in Airgun Illustrated. I don’t think bats need as much energy as pigeons.
Accuracy is far more important than pellet shape. I always go with domed pellets because they are the most accurate of all.
B.B.
I just got a new 1000 fps air rifle and when I try to setup the scope it says to shoot at a target 100 metres away.Not sur, but 300 ft seems a bit far for tageting with an air gun. I try to scope in at about 100 ftand I can’t get the scope to go up any higher. Any suggestion? The manual sights work great (within one inch of centre) at this distance.
The instructions for your scope are for a firearm. Read this article about sighting-in:
/article/All_about_scopes_Part_3_April_2005/22
B.B.
…which makes me wonder, what scope did you get? And if it’s a cartridge gun scope, is it airgun rated?
Also, what rifle did you get?
I own a .177 cal air gun that shoots at 1000fps. I have sighted it in for 50yds. and made a ballistic chart for it. it has a leapers 3x9x50 scope on it with a mil-dot reticle in it. so as long as you have those two things you can range with the scopes reticle and reference to the ballistic chart to make your scope adjustment, and your dead on every shot. the formula for finding range using the mil-dot reticle is:
height of target in yds x1000/height of target in mils= range in yds.
For you guys that think it would take way too long to make the adjustments on my scope, it takes me about thirty seconds to make adjustments. and if you purchase a mil-dot master or a mil-dot table it takes half that time. Go to Mil-dot.com to learn more.
B.B. Pelletier – Thanks so much for the simple explanation with numbers! I spent over an hour today looking up trajectories and doing a lot of crazy math trying to figure out my best crossing points. 20/40 sounds good. I have about 15/50 right now and am pretty happy with it. Just have to be careful at that pesky 30 yard mark where the pellet is 1.2” high. You are amazingly patient with these questions!
Kudos!
my dad and just bought the new gamo bull whisper, it has a velocity of 1300fps with the new pba ammo…at what distance would we want to sight in at? and what is the maximum effective range?
Michael,
The PBA ammo is not accurate at any distance past 10 yards. Using the artillery hold, the maximum effective range is the distance at which you can group ten shots inside one inch. With premium JSB Exacts, that should be about 30-35 yards.
Sight in at 20 yards and you will be within 1/2-inch out to 35 yards or so.
B.B.
what about the hight of your scope off the barrel,would it come into play also? a small 20mm scope on low rise rings would have a different optium setting than a 50mm scope on high rise rings. It seems trajectory intersections would change with center to center bore/scope plane differences
Scope height does come into play, but it's only critical at short ranges. After 20 yards it pretty much doesn't matter, which is why I ignore it.
Also, the 20mm scope objective is usually on an inferior optic, so the benefit gets cancelled by the brightness and sharpness of the better glass. But that only holds true when my assumptions are correct. There are vintage scopes with small objectives and good glass that do work much better.
B.B.
I have an air rifle that shoots about 650 fps what would you recommend as a sight in distance for that. I tries 20 yards and that seem a bit off.
Raceman,
Why is 20 yards off? Your rifle won't be flat-shooting at any range, but if you sight it at 20 yards it will be flatter at useful airgun distances than if sighted at 10 yards.
B.B.
I just bought my first air gun and reading this blog was extremely helpful. I understand now the physics behind the trajectory and scope. Good reading, thanks a lot!
Welcome to the blog. This report you posted to is over 8 years old. Please join us on the current blog at this address:
/blog//
B.B.
When I was a small boy, 55 years ago, my grandfather used to set up a black rubber ball hanging on a string at about 18 yards and tell me and my brother to keep it swinging… Used to aim at the string about an inch above the ball… no scopes back then. When out hunting rabbits his advice was to aim to skim the top of the Rabbits head. I got my fair share of kills with that advice. What was annoying was that my Uncle Cyril could do just as well using a catapult and marbles for shot… Love the science though.
Hi b.b Terry here just wondering .I have a Gamo shadow. 22 I sighted it I at 21 meters. At 10 meters it’s at the same .aim point does this seam right to u .the scope is a Nikko sterling air king 3x9x49 mill dot I am trying out find a mill dot chart for this range thanks
Terry,
Welcome to the blog.
No, it doesn’t seem right. At 10 meters the pellet is usually lower on paper than at 20 meters. Is your scope real close to the spring tube? If so, that could be why it’s shooting this way.
B.B.
B.B. (or anyone),
Does anyone here have some good data for their RWS 54 in .22 cal? I mean, data about what distance you zeroed your scope, with what pellet, and then what the second “zero point” is — i.e., 25 yds and 41 yds, or whatever they happened to be?
Thank you!
Jim M.
Jim,
I zero all my scoped guns at 20 yards, Depending on the velocity and the height of the rings, the pellet will then shoot flat out to 26-35 yards. A 54 will be flat out to about 30-32 yards.
B.B.
Can’t believe I’ve just read through 10 years of posts. Anyway, just doing some research on air rifles and scopes. Ive never owned an air rifle but I’m looking forward to doing so. Just want to make sure I’m going at it the right way.
I’m looking at a Hatsan At44 10 Pcp airgun. Looks like a half decent number to start off with. Just wanted to see if any one has had any issues with this model or if there is a better option out there. I like the sound of the hawke sport 4-16×50 Ao Ir airrifle scope also.
Any advice would be appreciated
Thanks in advance
Gary
Gary, my advice would be to repost this at the current blog. The blog you posted to is about 10 years old and few will see it, go here /blog//
Thanks for that mike.
Gary,
Welcome to the blog.
The Hatsan AT44-10 Long QE is a very good choice for a gun. There are others that are equally good, but you are not making a mistake with that rifle.
As you know from your reading, there is a lot to learn and the technology is in constant flux. But keep reading and we will be here to help you.
B.B.
Thanks B.B
I Read through a piece earlier, something you put on in July last year about the Hatsan. Pretty much made my mind up after that.
Seems like a lot of rifle for the money here in the uk.
Haha, it is quite overwhelming thee amount of information there is to take in. A lot to learn is definately correct.
Its has got me hooked already though and I Can’t wait to get out shooting.
Thanks for the help
Appreciate it
Gary.
⬆️⬆️⬆️⬆️⬆️⬆️⬆️⬆️
A bit random I know, just that I was searching for info about pellet drop, and I had a good read through. Lots of great information. Thought I’d pop a little question over.
Thanks
Seems that I’m not the only one reading thru( throught process) the previous blogs? Education is the name of the game! Semper fi!
Is there any formula that calculates 2nd zero knowing the 1st zero?…
i am having an anomaly I think. I haven’t seen this with any air rifle or smokeless powder rifle.
The rife: Benjamin Discover
Pellet: 18.1 JSB Diablo
PSI: 2000-1000
I have added a second barrel band and a TKO brake, but this gun was shooting this way before. It is stone cold accurate, but very odd.
I sighted in the first dot above the crosshairs at 10 meters. I prefer the dot as it helps me get a quicker sight picture. What confuses me is that the further out the target is say 25 yards I have to use the 2nd dot above the crosshairs, and at 40 yards I am using the 4th dot of the mil-dots. So I am actually dropping my barrel instead of raising it for further distances. It is confusing me. I thought that I’d have to adjust with elevation by raising the rifle barrel not lowering it.
Is this just the trajectory of my 18.1 grain JSB pellets? Anyone else ever experienced this? The rifle is dead on accurate. I am just confused I guess.
Chairgun estimates, using the nearest pellet in the database (JSB Exact Heavy18.0gr — I presume this is a .22 and not .177), with a velocity estimate of 800fps (based on the 2008 report here), scope height 1.75″… 10 yard zero…
The pellet will be almost 2″ high at roughly 35 yards, falling back through zero at 55 yards.
If you set the (second) zero at 38 yards, the pellet is only half an inch high at 28 yards, and has a first zero (rising) zero at 15 yards. The trajectory is +/- half an inch from line of sight between 10 to 43 yards.
Jeremy
There is no anomaly here, you are simply sighted in at a relatively short range of 10 meters using a 1 mil dot hold under when you should actually be using a hold over at this range. This is the point where your projectile first intersects your line if sight as it is rising, once it reaches the apex of its trajectory and continues downward, it will again intersect your line if sight. The C/L height of your scope above the C/L of the bore will have an effect on this also. You need to sight in at a longer range, 35 yards maybe, ideally so that you will have an approximate equal amount of hold over/under within the range that you wish to shoot.
Gunfun1 and others on this blog can explain it better than I can if this is not clear to you.
I just hit the refresh button before sending so I am not stepping on any ones toes!
Bugbuster
I have a gamo silent stalker whisper in .177 with gamo red fire pellets. Where should I zero in at im very confused because I’ve used a whole can of pellets on siting in already. I want to be able to shoot at long range (50 yards max)
Isak,
Welcome to the blog.
You can zero at 50 yards if you like, but that isn’t very useful. Your pellets will be low at all other distances.
I would zero at 20 yards. You will be on at 20 and just a smidge high out to about 35 yards, then back on again. This gives you the longest distance with the flattest trajectory you are going to get.
B.B.
I have a .30 FX Bobcat Mk2 that shoots effectively at over 100 yards. The maximum effective range is between 120 and 150 yards. I am able to consistently hit with a within 1″ circle at 105 yards. I use a bushnell laser rangefinder 4x12x scope that you can adjust the turret to compensate for drop. I have yet to set and mark the turrent, but I’m not sure what to initially sight it into.
I have a daisy 415 that shoots about 500 feet per second with a laser mounted under the barrel. At what distance do you suggest I zero the laser designator?
If it makes any difference this is powered by CO2 and I’m at 6500 feet elevation
Johncpen,
I would zero at 20 yards. That will keep you on target from 18 to 26 yards.
B.B.
Thanks for this and other answers recently. You’ve been a great help!
Obviously a newbe
My Question may seem simple 2 you but!
Ok I mounted my scope and zeroed in at about 10yrds. With my 1470fps gamo whisper pellet rifle. My BIG question is how do I know if I “zeroed “it in on the near zero or the far zero ? I can’t find this out anywhere.
Someone please come to my mental meltdown.
Thnx
Dave
Dave,
Welcome to the blog.
It’s not a bad question. One way to know is to shoot farther than 10 yards. If the pellet rises above the aim point, it was the near zero (which I know for a fact that it is). Your scope is mounted high above the line of the bore and 10 yards is extremely close to zero it.
I would normally zero a scope on a rifle like yours at 20 to 25 yards. It would them rise about a pellet’s diameter after that, and sink back to zero at 32-35 yards. With the scope zeroed at 10 yards it’s going to rise more than an inch by the time it gets to 20 yards.
B.B.
Dave,
Check out this site. Lots of good info. and some of the stuff is interactive (you can change things in real time).
http://www.arld1.com/
Chris
B B: thnx I think I got it. I will try this technique. We just got 14″of snow (I live above Philadelphia) so I’ll have to wait a bit. I’ll post after snow melts just a bit .im dying to get this thing aligned.
Dave
Dave,
Check out this Chairgun program from Hawke scope’s web site. You enter your data such as caliber, pellet shape, pellet weight, etc. and the program will calculate the pellet’s path. It will give the best distance to zero in at as well as give you the PBR (point blank range) distances near and far. It will also give you the pellet’s drop out at longer distances in inches or mil-dots. The program is free to download. You may need to install JAVA for it to run too. Here’s the web site where you can download it from:
https://uk.hawkeoptics.com/chairgun.html
Geo
Thnx Geo791
After review/using this recommended app I see that I must use the near zero point because I can’t get the far zero point down to 20 yds. Which is about what I plan on shooting @. Because I need to know if I miss my target the pellet will hit dirt and not a living object.
Very useful app. I like it and will use it. Especially the graphs, I’m a graph person.
Now I understand why I had to adj scope with so many “clicks” when I was shooting @ 32 ft.
My conclusion is that it doesn’t hurt to use the nero zero point I just have to remember that my pellet is still rising a bit before it comes down to zero again @ about 35yds.
Thnx again
Dave,
No problem, we all here to help each other. I would suggest that you post in the most current blog. B.B. sees all posts to any blog no matter how old but many of the commenters only see the posts in the current blogs. A few of us do scan for all new posts, even in older blogs and that’s how I saw your question. You would have gotten many more comments in a current blog though.
My biggest problem was, and I still have to keep in mind, that when I have my rifle sighted in a 25 yards and then shoot at 10 yards, my shot will be about an 1/2″ low and I have to use a slight holdover. This is counterintuitive because it would seen that at very close range you should aim lower on the target, but no, you have to aim higher. This is because the scope is approximately 1.75″ above the barrel. I can’t tell you how many times I have missed my target because I aimed low instead of high.
FYI, I am shooting an 18.1 gr pellet at 750 fps with a kill zone of +/- 1/2″. When sighted in at 25 yards my point blank range is 14 yards to 31 yards which is the near and far zeros. Chairgun shows the optimum zero to be at 32 yards but I don’t normally shoot that far. My bluebird boxes are 25 yards from the back of my house and I have to keep the sparrows from harassing the bluebirds. Actually the sparrows will kill them if they can catch them in the box! That’s why I need a very accurate airgun to take care of the problem.
Geo
I have a Gamo Magnum in .22 cal. rated a 1300 FPS. Real world FPS is 1150 with a 9.7 grain pellet. What range should I sight my rifle in at? I’ll be using between 15 and 16 grain pellets. I getting between 830 and 846 FPS in 16.36 grain pellets and 879 FPS with the gamo red fire pellets weighting in at 15.4 grain. Would a 12.65 grain pellet be any good to me, running at 1005 FPS?, Or should I sick with a heavier pellet? My main concerns are FPE and long range hunting. All suggestions and advise are welcomed
Yancy,
Welcome to the blog.
I would zero at 20 yards with your rifle shooting in the mid 800s. That should give you a point that’s right on from 20 -277-28 yards.
B.B.
What about the 12.65 grain pellet at 1005 FPS? Is that pellet too light to use for hunting?
Yancy,
How accurate is it? If you can hit a quarter 10 times out of 10 at the distance you intend shooting, go with it.
B.B.
B.B.,
You beat me too it! 😉 I was going to suggest 5/5, 1″,… but as you have taught us,…. 10/10 is the benchmark.
Chris
I’m using a Leapers 4-16X50 scope. That quarter should look pretty big at 50 yards. I’m very new to this air gun thing. I’ve watched about every you-tube video I can find, but there is so much more to learn. Are there any websites I can visit to get a better understanding of FPE, pellet weight and pellet velocity?
Yancey,
How about it, guys? Where should he go for good videos?
B.B.
Hi, any help in choosing which rifle scope to purchase? I’ve considered the Bushnell FFP BTR-1 rifle scope and yes it has received very good reviews with a few little downsides, here’s the reference for the article (https://www.pointoptics.com/best-rifle-scopes/). Do you think it’s a good buy for a beginner like me?
Richard,
Welcome to the blog.
We need to know what you shoot with your airgun that is getting scoped. Are you a hunter or is this for plinking? What airgun is it going on?
If someone asks which truck they should buy the range goes from a micro pickup to a 10-ton dirt hauler, with a lot of possibilities in-between.
B.B.
I zero all of my scopes at the rounds Apex. That way I only have to do hold over and never hold over & hold under.
A very (extremely) late comment about only using one zero distance.
If you are dialing your scope instead of holding over/under there’s an advantage with a single zero at the top of your trajectory as you only will have to dial in one direction.
It can be very easy to get lost on your turret, but with a zero stop and all corrections going the same way from there you’ve made it as easy as possible to make a hit with your first shot as long as you can determine the range