Okay, I have yet to own a rifle (let alone a scope, etc.), but have my sights set on a 15-22 MOE when it comes in. My birthday was yesterday, so please cut me some slack with my stupid question:

I'm an engineer (i.e. troublemaker), and tend to put everything in spreadsheets or CAD or sketches. I see that any sight, especially a high-mounted scope, has to point way down, in relationship to the barrel, to hit at any distance.

My question is: Do scopes have a built-in downward slope to allow for this? Or are they actually mounted parallel to the barrel, and all the downward scope is accomplished through adjustment?

I've read several articles on adjusting a scope, and they suggest bore-sighting to a location, then pointing the scope to that location. But the mounts I'm looking at (QD double mount) don't appear to have any adjustment. In fact, even separate rings don't seem to have any, do they? If that's the case, isn't the pointing location of the scope completely determined by the mount, and unless something is built in sloped, automatically parallel with the barrel?

Yeah, I know you're all probably rolling on the floor laughing; but I'm really trying to understand how this works.

Please be kind. ;-)

The only stupid questions are the ones NOT asked. Every scope has a full range of adjustments built in. At longer ranges (1000 yards and up) you can buy 20 moa mounts that will allow more elevation adjustments. If you are shooting at 600 yards or less the built-in scope adjustments will work fine.

Let's talk engineer (I'm a physicist, but spent my share of time in engineering classes, too).

First, the angle between the line of sight (LOS) and line of departure (LOD) in a .22 LR shot at normal .22 LR distances is small comparted to, say, a Palma rifle. Thus, good quality fixed rings are quite adequate, without getting adjustable rings. The internal scope adjustments take care of zeroing it.
Second, it is to your advantage to get a scope specifically made for a .22LR so the parallax will be set for .22 distances, not for 150yds, which would cause misses at normal .22 LR ranges.
The good news is that there are several such quality .22LR scopes in the $150 to $200 range.
For most normal shooting with the 15-22, .22LR scopes under $100 like the Simmons are quite adequate. The rifle is a fun plinker, not an Olympic bolt .22, and extreme precision optics are not needed.
You know the old engineering saw about "why measure with a micrometer if you're going to mark with a piece of chalk and cut with an ax."

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Science plus Art

See... no BLOOD was drawn becouse of yer question.....

Actually was a REAL good one.... i learned a bit myself

WELCOME to the addiction buddy....

Start buying mags and AMMO now... youll need it

LOL


Stav

IMO there are 2 answers to your question, maybe 3. an AR can be mounted as close to the bore as possible on a red dot or holo. my EXPS-1 Eotech has a 7mm riser so that it will co witness the lower third of the buis. it all depends on how much upward or downward adjustment the scope has. a normal hunting scope on a bolt action is mounted low and then the butt of the stock is matched with our face to get a good picture. my McMillon .308 has a 20mm rise on the mount so that i can get more upward elevation for longer distance since it will run out of elevation at a certain point.
so it can go both ways, elevation and incline decline via internal scope adjustment or by the mount.
all my AR's have straight mounts, all LaRue, and the dots have no issue with elevation settings.
sighting in has several schools of thought but the main 2 are to 1. shoot at the center of the target 3-5 shots then leaving rifle in exact same position, move the internal reticule until it is hitting in the middle, so you are adjusting to the middle.
2. the one shot zero is better IMO. take 3-5 shots, leave your rifle in exact same position it was and then adjust scope so that the cross hairs are in the exact middle of the group that you fired. you should then be centered almost in the bull. another 3 round group for micro adjustment, re set zero on dials, lock it down and you are done.
just remember that in either, the rifle needs to be as solid as possible so if you have or can borrow a lead sled of some sort they are invaluable round savers. the less lead sent downrange when zeroing the more to use for practical shooting at known distances as if hunting or dialing in exact as in benchrest zero shooting.
My .02 and how i do it, i'm sure there are others that will chime in with the different ways they do theirs. no one is wrong as long as it works for you.

Right. But they have a limit. According to my calculations, a sight on a 15-22, if mounted 3" above the barrel centerline, and exactly parallel to the barrel, will have to be adjusted down about 16" at 100 yards. If I'm doing it properly, that's 16 MOA or 64 clicks of 1/4 MOA. In only one direction (down). I see a lot of scopes, like the Sweet 22, saying they have a range of + or - 35. Is that +/- 35 MOA, or 35 clicks? If clicks, I'd be in trouble. If MOA, then it would work fine.

Stav, where you at in the "Desert"? I'm in the "Real Desert" of AZ!!

hence the adjustable rings or higher sloped bases to mount on. the variety is endless. i would go to the this or the other forum and look at the picture threads and see what type of scope and mounts they are using and then you will get the idea. practical for my .22 is maxing at about 150y and that is it for using the dot. everything else is kentucky windage, but i would not be taking small game shots at 150, it would be for S&G's at the gongs on the range.

DITTO....... In Glendale

Heading out to PLAY any minute..... but still on this stupid Computer thingy.....LOL

I'm a mathematician and teacher, if this is a stupid question I don't want to know what a hard question from you would be! Thanks for the interesting query.

Well, it didn't seem stupid to ME. To me, it sounded fundamental and important. But in all the reading I've done, no one seems to be concerned about the fact that a scope parallel with the barrel will /never/ be pointed correctly in itself. And a mount maker I contacted mentioned I could use another 1/2" spacer, but that I might then run out of scope adjustment to hit the target. So it really got me thinking.

I still don't understand how so many scope mounting tutorials just say to leave the scope loose until it's pointing exactly to where the boresight is pointing, then tighten it down, when it doesn't seem that most of the mounts have any real adjustment; they're just clamps, after all.

Mounting the scope that far above centerline on the 15-22 is a mistake for practical shooting reasons, i.e., you aren't going to be able to get a "cheek weld" solid position, and are going to be wobbling all over the place. If you mount the scope colinear with the iron sights, you will have a stable shooting stance and backup sights if you have to remove the scope.
Take a look at the multiple sights on 3-gun competition rifle and you'll see the additional sights mounted on the side, not stacked up on top of each other.

My neighbor ignored everyone's advice and stacked all his sights vertically, but later changed them after shooting some friendly club matches.

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Science plus Art

A post on another forum was a great help. It's specific to the AR15 but concept is the same.

AR-15 Zeros and Trajectories - AR15.COM

I'd like the scope colinear with the iron sights, but 1) Near as I can tell, the iron sights are about 2.6" above the barrel centerline (again, I don't yet have the rifle; I'm scaling off pics and looking at Magpul's specs). And using an NCStar cantelever scope mount or equivalent, I calculate the scope's centerline will end up about 2 3/4" above the barrel centerline. I rounded that to 3", but I don't think the average mount, at least if it's going to clear the folded MBUS sights, will be much less than that.

Practically, I'd love to have the scope cowitness with the existing sights, but that would mount it quite a bit higher.

EXCELLENT post! It will take me some time to read and understand, but it may well answer my questions. And I KNOW it will answer questions I haven't thought of yet. Thanks! :-)

Suggest you visit one of your clubs having .22 matches and look at the 15-22 setups being used. Most are happy to show off their equipment and answer questions. Take a box of .22 with you and they probably will let you shoot some.

Added:
Here's a ballistic calculator so you can genterate some actual .22LR curves.
http://handloads.com/calc/index.html

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Thanks. I've calculated and graphed ballistic curves for my intended rounds, so I have a pretty good idea of that. Actually, I calculate that if my scope is mounted 3.5" above the bore, I'll be able to shoot with the same zero at 25 and 100 yards, but that's probably higher than I really want to put it. And as OKFC05 mentioned, cheek weld will be a problem if I get too high. I can get a cheek pad, but then it will be too high for the iron sights, so IMHO they the two should be as close as possible. Which, in my case, will be having the scope as low as possible and still clear my folded MBUS rear sight.

When I got my 15-22 I knew I would want a scope on it, and never having owned one before, the issue you raise was on my mind.
Here's a path graph I generated for my current setup (Nikon 4x32 zeroed at 25 yards). Bullet-drop is actually my friend, since it counters the effect of the scope not being coaxial with the barrel.
In playing with the Spot On program from Nikon I was surprised at how little difference scope height makes at the distances I shoot at. My scope is 2 5/8" above the barrel, but the most I have to adjust is an inch.
You asked your question in the right place. These guys are always ready to help. Just don't make the mistake of calling your magazine a "clip."

Attached Images

Scope Path Graph.jpg (10.2 KB, 34 views)

I still wonder if scopes aren't already "optically pointed down." ;-) I mean, NO scope can be mounted less than say 2" above the rifle bore, and even a fast bullet will drop over 1" at 100 yards. So a scope mounted perfectly parallel to the bore will always be AT LEAST 3" high at 100 yards, and would NEVER need to be corrected above zero. Seems it would make sense to "point" them down a bit, so as to give more /usable/ adjustment, up and down.

But maybe I'm over-analyzing.... ;-)

Ah, my internet connection was on the fritz while I was trying to post so now I see that you are way ahead of me.
I've learned that the most important thing is getting the scope so it's comfortable, and of course so it works with any other sights or devices you want to use.

Hey, you're an engineer. Enough said.
I suspect you are correct about the optical pointing of the scope right out of the box. When I first mounted mine I separated the lower receiver and clamped it securely so I could look at a target through the barrel and through the scope. The crosshairs appeared to be right on the money just the way I bolted the thing on, and subsequent trial on the range proved that observation to be correct.

It would be interesting to take a scope adjusted to IT'S zero (right out of the box), check where it's pointed when mounted, then turn it upside down to see if it's pointed at the same place. ;-)

While we're on the subject (kinda), I've seen some scopes that have some sort of "zero reset" or something. Is that something that will reset the zero to the same starting location after making manual adjustments? How is it used? How important is it? What scopes have it?

Along those lines, when you've finally adjusted a scope to your liking at a given distance, can they be then adjusted to read zero, making going to that setting easy, and so you don't have to remember "17 clicks down from zero"?

I believe the reason they say not to clamp down has to do with left/right adjustment, not up/down. Whether using a "turn in" style, or weaver style, there is always left/right adjustment in the rear ring. Having the scope line up with the bore before tightening has more to do with making sure the rings are aligned, rather than the scope adjustments. Rings even slightly out of alignment will cause all kinds of problems. I always lap my rings as well when mounting a scope. The more surface area you can get holding that scope the better.

That makes sense. But many times they tell you to, without touching the scope's adjustment, center the crosshairs on a mark which the boresight is pointing to, and I don't see how that would normally be possible.

Without touching the scope's adjustment, the only centering you can do is left/right. I've mounted a lot of scopes, never had one that would line up up/down with a boresighter without adjustment.

Try YUMA baby!!!! was 102 today already!

Yes you want a scope with resetable turrets. It can mean a couple of different methods but basically you adjust and sight in the scope at your distance (usually 50 yards for .22 LR). Then you either pull up or unscrew the turrets and rotate them around till the "0" is facing you and tighten them down again.
As for ammo the most accurate class of ammo for .22LR is standard velocity. This has a lot to do with the behavior of the un-aerodynamic .22 bullet when it is around the sound barrier. Even though this class of ammo has the biggest bullet drop it will more likely land where you want it to than any faster class of ammo. But the AR15-22 is not like a precision bolt gun like rimfire precision shooters use. It shoots reasonably well out to 100 yards and somewhat further if accurate ammo is used. As for the scope my rational has always been to mount the scope as low to the bore as possible to reduce the scope bore axis separation. This way the range of bullet impact plus or minus 1" of the sight in point will cover a longer range than if you mount it higher. You should not need a scope offset unless you are trying to shoot beyond 200 yards with SV ammo. And just so you know a scope mount/rail with a 20 MOA offset points the nose of the scope lower than normal, which of course raises the barrel in relation to it so that it will shoot at a higher angle, and i.e. go farther (I am an electronic engineer and competition shooter). The 2 brands of ammo that shoot the tightest groups in .22 are Lapua and Eley, both of which are rimfire match ammo. The most accurate easy to locate ammo is CCI Standard Velocity (Dick's SG at 500/$25. Also look for Wolf Match Target and Match Extra. Russian ammo but some like it.

If you really want a good scope then the scope rated the best value for an AR .22 trainer is the MidwayUSA exclusive BSA Tactical Mil Mil 4-14x44 FFR SF MRAD scope. Has all the features you usually find in a $1000
tactical scope for around $250 on sale ($399 list). Features include resetable to zero turrets, First Focal Plane reticle, side parallax adjustment from 10 to 500+ yards, 1/10 mil adjustments, and MRAD reticle with 17 marks below the crosshairs for extended shooting without adjusting the scope. Not everyone needs 14x, as I find on my multigun AR I can engage targets out to 250 yards with just a 1-6x24 tactical scope. But hey I have enough eye issues at 64 YO that I like more power if I can get it.

one of the reasons i have gone to the lower power FFP's is due to having the other type scope on lowest power say 3-4 and i'm using the rifle (not necessarily the 15-22) and a dog comes in at 15 feet through a wash. try finding him in the scope in the 1.5 seconds before he knows it's a trap. aint happening and if it does all you see is fur but not where. so you try to grab the SG that is laying across your lap for that final try with 3" #4 buck, maybe you get him, most likely not.
the lower power 1-4 or 5 FFP's with the red dot or in case of the Weaver has a red dot that washes out in bright sun but it does not matter since it shows up total black for daylight shooting, is that on 1 or 2 power, both eyes open, that same dog has no chance. no i could take a normal scope and mount a 45 degree offset RDS on it but then there is more weight and another learning curve i have to go through. most of the hunting shots here are well within 300 yards, so the 4 power with MPBR is a great set up for where i live. 39 dogs last year cant' be wrong....along with the fox and bobs...just ask them, they are in Russia right now being made into hats after the fur auction!

I agree, and use subsonic ammo in all my target pistols, but S&W states not to use ANY subsonic ammo in the AR-15.
Actually, that part depends on what distances you want to shoot at. In theory, the best you will get is absolute accuracy at two distances, and those distances are determined by the velocity profile of the bullet and the height of the scope. Mounting too low can really limit you. If it were possible to mount the scope at the same height as the barrel, then one of those distances would be 0, right at the barrel end, and the other at whatever distance it's set at. For Federal ammo, if I want to shoot at 25 and 100 yards, it actually works out that the scope should be 3 1/2" above the bore. This would allow me to shoot at 25 and 100 with absolutely no sight changes. It would shoot high between 25 and 100, and low below 25 and above 100. The theoretical sight height can easily be calculated based on that information.

However, it's not always the best place to put the scope. On the 15-22 MOE, the iron sights are about 2 1/2" above the bore; making that much higher means your eye, and cheek, will be much higher with the scope, and that of course causes a problem.
I agree with that. But pretty much ALL sights for a .22 are going to end up having to point down about 15 MOA on average, so whether you get that all in the scope internal adjustment or get most of it in the mount would make little difference.
All good ammo, but again, standard velocity, which I'll be avoiding with the 15-22 (per S&W's spec).

Thanks for the info.

I'll be using my 15-22 for targets only, so a lower power range won't really be that helpful, but thanks.

Can you confirm or deny any of the measurements given on Midway's Page for this Scope? The dimensions they give don't add up (3.69 + 5.75 + 3.625 don't equal 13.3), and the C and D dimensions don't look right, as that would make the focusing block 2.25" long, which it does not appear to be. I'm also concerned a bit with the 43 mm diameter for the ocular end of the scope; the diameters are the only dimensions given in mm, and I'm a bit afraid it's the glass diameter, and not the outside tube diameter, which means it may not clear my MOE's folded sights.

rraisley- Glad to have you on board. I have never seen someone that could have this many questions about EVERYTHING., except myself. I now know that I am not alone in the world. I would rather use a micrometer than a tape measure!!! It becomes very tiring at 200 yards!! Most of all be safe and enjoy. ViperMD

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Did you not see that I was an Engineer?? ;-) I have to understand everything I work with, or if not, find out why. I now have layouts of 2 sets of mounts with four different scopes on a 15-22 MOE - and I don't yet own the gun! A friend gave me a motto a long time ago:

"Anything worth doing, is worth over-doing."

I saw you were an engineer, and I wondered what kind when I saw you were using qd mounts. What are they made of, will you lose metal each time you open and close them? Should you open the front or rear first depending on the mass of the scope? How much will this affect your point of impact? Will it be a linear loss? Just a few questions I had.

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I BACK OUR BLUE

I see someone is after my "Most Questions" trophy. ;-)

My degree is in Aerospace, but I've worked as a Mechanical most of my career, with the last 10 years or so mostly computer programming.

I'm not experienced enough with scopes to answer those questions, but my experience tells me:

A properly designed quick disconnect should not lose much if any metal. The position of the scope is determined by the non-QD side, so even wear should not affect it. If they wear, there is adjustment to make them tight again, and again, that's only in how tightly they hold, not where they're positioned. Front or back shouldn't make a difference, but like anything with multiple fasteners, tightening a bit at a time, with a final "snap" in position after it's in place would make sense.

But that's just my engineering experience talking, not any actual experience with mounts. I'll let someone else tell me where I'm wrong.

As to mounts, I've found two I like:

NcStar QD Weaver Mount/ Cantilever Scope Mount MARCQ - Pretty good mount with single disconnect, and 0.95" from top of rail to bottom of 30mm tube. Seems very good for $26.

Burris AR-PEPR Scope Mount - Very nice looking, cantilevers a bit further, 1.00" from top of rail to bottom of 30mm tube, sturdier with 2 separate locks, but $77.

I'm leaning toward the Burris due to the double locks, one-piece milled construction (not sure about the NcStar), and it's a touch higher, and I may need the clearance.

Neither will allow me to co-witness with my iron sights, but to do that, I'd need a QD riser, and separate, high see-through mounts, and that will put the whole thing another 1/2" or 3/4" higher (maybe more), so don't think I'll do that.

Poor rraisley, after reading all this he will be so confused!

I have used the NcStar QD on 223, and 12 ga without any problems, despite their price, which means if they do not fit your needs you can always put them on something else. I agree the Burris appear stronger, I have not used them and on a 22 lr it may be a moot point. Be Safe,

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I BACK OUR BLUE

Reading it??? He WROTE most of it! :-)

Okay, the local store (Palmetto Armory) just lowered the price of the 15-22 MOE today, so I went and picked one up. Also, just ordered the BSA Tactical 4-14x44 Mil-Mil scope from Midway, along with Butler Creek hinged covers. Looks like the scope will clear the sights, and I'll probably go with the Burris AR-PEPR Scope Mount, just because it looks good and has dual clamps.

Now, to accessorize! :-)