Stupid Question of the Day (Year?)

[RolandW]

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

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.

 

[rraisley]

I suspect you are correct about the optical pointing of the scope right out of the box.

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. ;-)

 

[rraisley]

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"?

 

[gdogs]

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.

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.

 

[rraisley]

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.

 

[gdogs]

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.

 

[roadkill45]

DITTO....... In Glendale

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

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

 

[photoracer]

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"?

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.

 

[photoracer]

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.

 

[roadkill45]

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!

 

[rraisley]

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.

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.

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.

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.

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).

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.

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.

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.

 

[rraisley]

...39 dogs last year cant' be wrong....

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

 

[rraisley]

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).

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.

 

[vipermd]

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

 

[rraisley]

rraisley- Glad to have you on board. I have never seen someone that could have this many questions about EVERYTHING., except myself.

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."

 

[vipermd]

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.

 

[rraisley]

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.

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.

 

[watergun1929]

Scope Adjustment

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

 

[vipermd]

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,

 

[rraisley]

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

Reading it??? He WROTE most of it!