Scope question

[Snappo]

Just wanted to walk through a situation and have you guys help me think through it.

Weapon: Remington 700 XHR with Boyd stock. A washer between the barrel and the lower front floorplate screw so that the bolt does not bind when i screw it in tight.

Scope: Pentax LightSeeker 30 8-32 20mm. Rings are Burris and the scope base is Picatinny.

Issue: When I zero at 100 yards, the lowest my crosshairs can dope is 2" above the point of bullet impact. It seems to me that this scope was 60 MOA or 80 MOA; and I am not using 20 degree rings or anything else to change the scope being parallel to the barrel.

My thoughts: Other scopes worked perfectly so I am thinking this scope is off? I am also thinking that since I have 3 of these scopes and this would be the second one to fail, that I should ditch all 3 of these. I paid $800 or so each, so it pains me to walk away from them.

Unless someone has a solid idea of what I can do to get this scope dialed; my thought is to put all 3 Pentax units on a shelf as spares (and work on getting Pentax to look at it out-of-warranty), and go with a Nikon P308 4-12x40 for $250 at Midway USA.

 

[Snappo]

ETA: I just threw caution to the wind and got the P308 and Burris one-piece mount setup with the quick releases.

 

[ProgSpear]

I'm guessing you physically measured the rings to insure they are identical. What happens if you swap the rings front to back? If you have the same issue then either that scope is caca, or it just became your 500+ scope (assuming it holds the box)

 

[meketrefe]

You don't want a rifle to verify the scope. I suggest the following:

A) Take out the scope and align the mechanical center in line with the optical center and reticle. You can do this by putting the scope against a mirror with a glass in between and make sure you have some light coming back.
You will see the reticle twice, one is the reticle in the 2nd focal plane and the other the reflection of the reticle in the mirror. Make them match overlaping perfectly and you
will have an optical center. It is not 100% precise but it should be very close. Take note of the turret values and now lets find out the actual adjustment. if the scope is in the center and
you have lets say 60 moa of elevation the elevation adjustment should go 30 moa up and another 30 down from that position. So start counting the clicks and then multiply
by the advertised click value. So 1/4 MOA adjustment should result in 30x4 that is 120 small clicks. Come back to your center 120 clicks and then verify you are now in the center again.
If you are not then you either made a mistake counting or your erector tube has some serious reliability issues. Do the same on the other direction. Might want to do the same with the windage.
This will verify the travel "mechanically" and I will verify that there is potential for the scope to adjust to whatever values they advertise. Lets say if you don't get to 120 but 100 clicks it should be
fine as soon as it is consistent on the other direction. +/- one or two clicks could be fine too as optical center and mechanical center might not be 100% correct. The key here is to know the range of movement and to make sure that if you didn't make a mistake counting the clicks and taking note the crosshairs should be in the precise spot you started. Return to optical center.

B) Now we want to verify that the mechanical movement in fact corresponds with a real MOA value corresponding from the movement. For this you will need to secure the scope so
it doesn't move. like clamped to a piece of wood to a rigid bench and setup a target to a predefined known distance. Set your scope in the optical center, set a target and focus on the
target. set a mark on the target dead center on the cross hairs. It might be wise to use a target with a grid with known squares we can measure like one of those in inches for example.

Now lets say do an adjustment with the elevation to elevate the erector tube lets say 10 MOA. If you do this at 25 yards this will translate in 2.61 Inches.

Distance Rough MOA True MOA Equivalence
25 yards .25 inches 0.2618 inches
50 yards .5 inches 0.5236 inches
100 yards 1 inch 1.0472 inches
200 yards 2 inches 2.0944 inches

Go to the target and measure the distance between the reference mark and the new position on the target. If you are not anywhere close come back to the center and do
the same with lets say 20 moa. The key here is to make sure that neither the scope nor the target move at all. You might be able to do this in your yard whatever the distance
and using math to calculate the mean value and actual value.

Here also when coming back to the starting point in click value the cross hairs should be in the precise spot you started in the target. Return to mechanical zero.

If the scope doesn't respond to the advertised calibration system then you might want to find one that does.

Also if you want to do the above with the rifle vs. a bench you might alternatively use the rifle but you have to make sure the scope is properly mounted and you use a quality
boresighter to verify the movement of the corrected values vs. the bore. I don't think that you might have mismatched rings because that would be obvious and might even
break the scope as you torque it down. Of course make sure nothing is loose that would not be the first time someone overlooked this during installation.

Makes sense?

Good luck

 

[NirvanaFan]

You don't want a rifle to verify the scope. I suggest the following:

A) Take out the scope and find the optical center. You can do this by putting the scope against a mirror with a glass in between and make sure you have some light coming back.
You will see the reticle twice, one is the reticle in the 2nd focal plane and the other the reflection of the reticle in the mirror. Make them match overlaping perfectly and you
will have an optical center. It is not 100 precise but it should be very close. Take now of the value and now lets find out the actual adjustment. if the scope is in the center and
you have lets say 60 moa of elevation the elevation adjustment should go 30 moa up and another 30 down from that position. So start counting the clicks and then multiply
by the advertised click value. So 1/4 MOA adjustment should result in 30x4 that is 120 small clicks. Come back to your center 120 clicks and then verify you are now in the center again.
If you are not then you either made a mistake counting or your erector tube has some serious reliability issues. Do the same on the other direction. Might want to do the same with the windage.
This will verify the travel "mechanically" and I will verify that there is potential for the scope to adjust to whatever values they advertise. Lets say if you don't get to 120 but 100 clicks it should be
fine as soon as it is consistent on the other direction. +/- one or two clicks could be fine too as optical center and mechanical center might not be 100% correct. The key here is to know the range of movement and to make sure that if you didn't make a mistake counting the clicks and taking note the crosshairs should be in the precise spot you started. Return to optical center.

B) Now we want to verify that the mechanical movement in fact corresponds with a real MOA value corresponding from the movement. For this you will need to secure the scope so
it doesn't move. like clamped to a piece of wood to a rigid bench and setup a target to a predefined known distance. Set your scope in the optical center, set a target and focus on the
target. set a mark on the target dead center on the cross hairs. It might be wise to use a target with a grid with known squares we can measure like one of those in inches for example.

Now lets say do an adjustment with the elevation to elevate the erector tube lets say 10 MOA. If you do this at 25 yards this will translate in 2.61 Inches.

Distance Rough MOA True MOA Equivalence
25 yards .25 inches 0.2618 inches
50 yards .5 inches 0.5236 inches
100 yards 1 inch 1.0472 inches
200 yards 2 inches 2.0944 inches

Go to the target and measure the distance between the reference mark and the new position on the target. If you are not anywhere close come back to the center and do
the same with lets say 20 moa. The key here is to make sure that neither the scope nor the target move at all. You might be able to do this in your yard whatever the distance
and using math to calculate the mean value and actual value.

If the scope doesn't respond to the advertised calibration system then you might want to find one that does.

Here also when coming back to the starting point in click value the cross hairs should be in the precise spot you started in the target. Return to mechanical zero.

Also if you want to do the above with the rifle vs. a bench you might alternatively use the rifle but you have to make sure the scope is properly mounted and you use a quality
boresighter to verify the movement of the corrected values vs. the bore. I don't think that you might have mismatched rings because that would be obvious and might even
break the scope as you torque it down. Of course make sure nothing is loose that would not be the first time someone overlooked this during installation.

Makes sense?

Good luck

I just wanted to say it's awesome having you here. This is a great write up.

 

[meketrefe]

Thanks. I hope this method is simple enought and it works for the Snappo to debug his problem.

I think scope manufactures should make better documentation and online tutorials to educate shooters on how to check
for basic things and also how to take maximum advantage. I think optics are always a hot topic. It is estimated that about 2/3 of folks
have some sort of issue with the optics that goes from basic mounting issues, simple assumptions to more complex problems that also involve a
deeper knowledge of the equipment and decent understanding of the ballistics.
I will be creating a thread to talk about optics. General function, what to look for and how to verify it is working for us based on individual needs.
There are many good companies and glass and with that large offering there is also confusion.

 

[Celt]

I was waiting for meke to post. I forgot we can "ping" members by doing this. @meketrefe otherwise i would have done that earlier..

 

[meketrefe]

You know you can hit me up any time but what you mean with "ping"?

 

[NirvanaFan]

If you type @username it will show up as an alert for the user.

 

[Snappo]

You don't want a rifle to verify the scope. I suggest the following:

A) Take out the scope and align the mechanical center in line with the optical center and reticle. You can do this by putting the scope against a mirror with a glass in between and make sure you have some light coming back.
You will see the reticle twice, one is the reticle in the 2nd focal plane and the other the reflection of the reticle in the mirror. Make them match overlaping perfectly and you
will have an optical center. It is not 100% precise but it should be very close. Take note of the turret values and now lets find out the actual adjustment. if the scope is in the center and
you have lets say 60 moa of elevation the elevation adjustment should go 30 moa up and another 30 down from that position. So start counting the clicks and then multiply
by the advertised click value. So 1/4 MOA adjustment should result in 30x4 that is 120 small clicks. Come back to your center 120 clicks and then verify you are now in the center again.
If you are not then you either made a mistake counting or your erector tube has some serious reliability issues. Do the same on the other direction. Might want to do the same with the windage.
This will verify the travel "mechanically" and I will verify that there is potential for the scope to adjust to whatever values they advertise. Lets say if you don't get to 120 but 100 clicks it should be
fine as soon as it is consistent on the other direction. +/- one or two clicks could be fine too as optical center and mechanical center might not be 100% correct. The key here is to know the range of movement and to make sure that if you didn't make a mistake counting the clicks and taking note the crosshairs should be in the precise spot you started. Return to optical center.

B) Now we want to verify that the mechanical movement in fact corresponds with a real MOA value corresponding from the movement. For this you will need to secure the scope so
it doesn't move. like clamped to a piece of wood to a rigid bench and setup a target to a predefined known distance. Set your scope in the optical center, set a target and focus on the
target. set a mark on the target dead center on the cross hairs. It might be wise to use a target with a grid with known squares we can measure like one of those in inches for example.

Now lets say do an adjustment with the elevation to elevate the erector tube lets say 10 MOA. If you do this at 25 yards this will translate in 2.61 Inches.

Distance Rough MOA True MOA Equivalence
25 yards .25 inches 0.2618 inches
50 yards .5 inches 0.5236 inches
100 yards 1 inch 1.0472 inches
200 yards 2 inches 2.0944 inches

Go to the target and measure the distance between the reference mark and the new position on the target. If you are not anywhere close come back to the center and do
the same with lets say 20 moa. The key here is to make sure that neither the scope nor the target move at all. You might be able to do this in your yard whatever the distance
and using math to calculate the mean value and actual value.

Here also when coming back to the starting point in click value the cross hairs should be in the precise spot you started in the target. Return to mechanical zero.

If the scope doesn't respond to the advertised calibration system then you might want to find one that does.

Also if you want to do the above with the rifle vs. a bench you might alternatively use the rifle but you have to make sure the scope is properly mounted and you use a quality
boresighter to verify the movement of the corrected values vs. the bore. I don't think that you might have mismatched rings because that would be obvious and might even
break the scope as you torque it down. Of course make sure nothing is loose that would not be the first time someone overlooked this during installation.

Makes sense?

Good luck

Thank you sir! I will play with that tomorrow.

 

[ProgSpear]

If you type @username it will show up as an alert for the user.

@Snappo, @meketrefe, @NirvanaFan

no real reason for doing this other than to be a pain in the ass...

EDT: Meke, nice writeup. thanks. It's always fun to get some gun talk on these political sites...

 

[meketrefe]

@Snappo I was thinking that if you cannot make work the step A don't worry too much but try to find the middle of the mechanical adjustment by counting the entire range
and then go back to the middle for both axis. In other words if you go up all the way then start counting down until you cannot go any further and then go back up half of the clicks. Take notes.
This with both axis should put you very close to the optical center. The main things is to do step B and make sure the actual adjustment corresponds with the mean value and you have enough of it not just to zero the gun but to shoot other ammo and adjust for longer ranges.
I would be surprised of any scope with just 2 MOA or so adjustment any direction. That would be totally wrong.
As far as the mounts and rings I cannot tell you but if you have the scope with the elevation and wind centered and w/o touching anything if put it on the rings is should run pretty much parallel to the bore, as you mentioned you do not have a canted scope mount.
make sure nothing is loose. But pretty quickly you should be able to find out if there is something funky with the scope adjustment.

Good luck.

 

[Podmonkey]

Thanks. I hope this method is simple enought and it works for the Snappo to debug his problem.

I think scope manufactures should make better documentation and online tutorials to educate shooters on how to check
for basic things and also how to take maximum advantage. I think optics are always a hot topic. It is estimated that about 2/3 of folks
have some sort of issue with the optics that goes from basic mounting issues, simple assumptions to more complex problems that also involve a
deeper knowledge of the equipment and decent understanding of the ballistics.
I will be creating a thread to talk about optics. General function, what to look for and how to verify it is working for us based on individual needs.
There are many good companies and glass and with that large offering there is also confusion.

I'm glad you're here too. Eventually I will be mounting a scope on the AR and I know basically squat about scopes. A "for dummies" breakdown is always helpful.

 

[Snappo]

Ima head out to the garage and find my micrometer now and try to solve this. I am gonna measure the rings and the base. Maybe I have something other than a true zero angle parallel to the barrel? Then I will try the mirror; which I am sure I will fuck up about 15 times before getting it. BRB.

 

[Snappo]

FAAAAAKKKKKK. I failed attention-to-detail 101. Crappin dog. Micrometer says the back of the base is 0.333 and the front of the base is .284. I put on a canted 20 MOA friggin base. LOLOL I bet if I go back there and zero at 200 instead of 100, I will be right as rain. But now I have that new Nikon P308 4-12 coming with the Burris extended scope mount. Mathematically, if I have at least 50 MOA then a scope should zero at 100 with a 20 MOA base. And the Nikon that's coming can do 60 MOA. So I should be set for the swap. But now I need to buy more long rifles to go with my Pentax scopes. Is it possible that 15 years ago the LightSeeker 30's were only 40 MOA? ;-(

 

[Snappo]

You don't want a rifle to verify the scope. I suggest the following:

A) Take out the scope and align the mechanical center in line with the optical center and reticle. You can do this by putting the scope against a mirror with a glass in between and make sure you have some light coming back.
You will see the reticle twice, one is the reticle in the 2nd focal plane and the other the reflection of the reticle in the mirror. Make them match overlaping perfectly and you
will have an optical center. It is not 100% precise but it should be very close. Take note of the turret values and now lets find out the actual adjustment. if the scope is in the center and
you have lets say 60 moa of elevation the elevation adjustment should go 30 moa up and another 30 down from that position. So start counting the clicks and then multiply
by the advertised click value. So 1/4 MOA adjustment should result in 30x4 that is 120 small clicks. Come back to your center 120 clicks and then verify you are now in the center again.
If you are not then you either made a mistake counting or your erector tube has some serious reliability issues. Do the same on the other direction. Might want to do the same with the windage.
This will verify the travel "mechanically" and I will verify that there is potential for the scope to adjust to whatever values they advertise. Lets say if you don't get to 120 but 100 clicks it should be
fine as soon as it is consistent on the other direction. +/- one or two clicks could be fine too as optical center and mechanical center might not be 100% correct. The key here is to know the range of movement and to make sure that if you didn't make a mistake counting the clicks and taking note the crosshairs should be in the precise spot you started. Return to optical center.

B) Now we want to verify that the mechanical movement in fact corresponds with a real MOA value corresponding from the movement. For this you will need to secure the scope so
it doesn't move. like clamped to a piece of wood to a rigid bench and setup a target to a predefined known distance. Set your scope in the optical center, set a target and focus on the
target. set a mark on the target dead center on the cross hairs. It might be wise to use a target with a grid with known squares we can measure like one of those in inches for example.

Now lets say do an adjustment with the elevation to elevate the erector tube lets say 10 MOA. If you do this at 25 yards this will translate in 2.61 Inches.

Distance Rough MOA True MOA Equivalence
25 yards .25 inches 0.2618 inches
50 yards .5 inches 0.5236 inches
100 yards 1 inch 1.0472 inches
200 yards 2 inches 2.0944 inches

Go to the target and measure the distance between the reference mark and the new position on the target. If you are not anywhere close come back to the center and do
the same with lets say 20 moa. The key here is to make sure that neither the scope nor the target move at all. You might be able to do this in your yard whatever the distance
and using math to calculate the mean value and actual value.

Here also when coming back to the starting point in click value the cross hairs should be in the precise spot you started in the target. Return to mechanical zero.

If the scope doesn't respond to the advertised calibration system then you might want to find one that does.

Also if you want to do the above with the rifle vs. a bench you might alternatively use the rifle but you have to make sure the scope is properly mounted and you use a quality
boresighter to verify the movement of the corrected values vs. the bore. I don't think that you might have mismatched rings because that would be obvious and might even
break the scope as you torque it down. Of course make sure nothing is loose that would not be the first time someone overlooked this during installation.

Makes sense?

Good luck

Turns out I am the poster child for screwing up. I had a canted base and thought I had a flat base. Micrometer found the error in my ways. But I do think that the Nikon P308 will be better for me since I hate having to use allen wrenches to adjust my scope. So I will now officially have 3 Pentax LightSeeker 30's sitting in their boxes on a shelf waiting for a rifle with a flat base. All my existing rifles are dialed in so I will just go as-is for now. Kills me to have over $2K of glass just sitting there on a shelf, knowing they won't ever find a home on a rifle. Sigh.

 

[meketrefe]

Oh!... but how much cant can a base have? More than 20moa would be rare and it actually should work for You adding to the elevation range of the scope by borrowing from the cant.
So I dont get why you are not able to zero and have plenty of adjustment left.
Nikkon are nice but the bdc have coarse reticle.

 

[Podmonkey]

Okay, when I do get my scope, likely a Trijicon 1x4 accupower, I plan on putting it in a cantilever mount, ADM or LaRue, something of that nature. Anything l thing I need to look out for to avoid similar problems? Anything beyond just buying the mount and slapping it on the pic rail?

 

[ProgSpear]

I would still think that the Pentax is still usable even with the 20 MOA cant - how does it dope when you use the top post of the reticle as the zero rather than the center of the crosshair? How does that relate to a 200 zero rather than 100 zero? I guess what I'm saying is that for the ultimate paper punch it might not be very good, but the deer won't know the difference between 2" high or low POI at 200 to 300 yards.

 

[meketrefe]

Okay, when I do get my scope, likely a Trijicon 1x4 accupower, I plan on putting it in a cantilever mount, ADM or LaRue, something of that nature. Anything l thing I need to look out for to avoid similar problems? Anything beyond just buying the mount and slapping it on the pic rail?

Not really just do not spend too much money for nothing. I don't like larue because the cam system bites into the receiver.
Not a huge thing but there are better ways with a stronger and more spread torque setting.
IMHO it is better something more sturdy and with full contact with the rail and most likely cheaper too.
Do you really like the 1x4 accupower?

 

[meketrefe]

I would still think that the Pentax is still usable even with the 20 MOA cant - how does it dope when you use the top post of the reticle as the zero rather than the center of the crosshair? How does that relate to a 200 zero rather than 100 zero? I guess what I'm saying is that for the ultimate paper punch it might not be very good, but the deer won't know the difference between 2" high or low POI at 200 to 300 yards.

You are right, in practical terms will not mean that much but also one should try to understand the scope and aim for accurate repeatable groups.
The more one is familiar with the equipment and the ammo the less chances we have to loose game due to poor placement. A small error that is not critical at 50 yards becomes a larger one
down range. And who knows, having the confidence of good shot placement can helps us decide if we take a more precise neck shot a longer ranges in a given situation.
I think the extra adjustment becomes necessary if we want the scope to work with any kind of ammo or changing conditions and many distances.
I just don't get why a 20 MOA cant would not give us a plentiful adjustment range regardless of the 100 yards or 200 yards zero.
It is very hard to help snappo any further w/o more information but it seems he is ok with putting the scope away.

 

[Podmonkey]

What do you recommend for a sturdy one piece QD mount? I do like the Accupower a lot, I was able to look through one at a gun shop and the clarity is amazing! The glass seems twice as nice what it costs. I have also heard that the accupower can withstand some abuse. This is for a SHTF rilfe plus I'm a klutz so that is important to me.

 

[meketrefe]

There are many good mounts w/o spending an eye in fancy looking useless cantilevers. Some cantilevers are so thin and long that I would not want them anywhere and very expensive ones
are made this way too. I like the absolute minimum cantilever for the scope to work. I am not planning in dropping the rifle or bumping everywhere but many modern styles
lack of the rigidity by design. Aero this, cantilever that.
I am not sure how critical is the QD but one simple robust cut with small cantilever would be perfect. Burris is a classic and Vortex has another one but I think the Midwest is
hard to beat. Remember some like burris, vortex, etc... are OEM so you might be able to find the same precise cut with a different brand.
But before you order the mount I would order the scope and bring it home. then you can take some basic measurements using several methods and tools (including masking tape) and decide
what mount needs to go in there to fit the rifle to your body complexity and shooting position.
Accupower are great scopes but IMO do not give anything too special vs. other 1-5 to 1-8 offerings. I mean with scopes like the Weaver tactical FFP, Burris XTRII, and Vortex Razor(A bit more moola)
and more power range seems like a good advantage. If you must have a 1-4 power and do not care about focal planes also check the Steiner P4x and sightron Stac. All the above are popular
among competition shooters and professionals. I mean is hard to go wrong with trijicon but I am just saying.

 

[Podmonkey]

I am just looking for something clear an rugged for 1k or less. Most 1x6 s seem to range above that, and 1x8s, fougettaboutit. If money weren't a concern I'd get an ELCAN but thems is expensive. I've looked at the vortex options and they are nice, but I've read, and I do NOT know this for fact, that they are more delicate than the trijicons. I have read many good things about the burris scopes but at there price point I can't imagine the clarity to be as good as the trijicons? I view the QD feature for the mount as being necessary for a serious use rifle, and I enjoy shooting irons so the ability to quickly dismount the scope and remount later without re zeroing would be helpful. And besides the SHTF consideration, I really am a klutz, no matter how hard I try to be careful the rifle is guaranteed to take the occasional header so I need gear that can stand up to that. You would not belive the abuse my 590A1 has been through! It would have seen better treatment aboard a Navy ship!

 

[meketrefe]

I think you also have the leupold VX6 now on sale at midway. The price is hard to beat. These scopes have been abused by professionals and safari hunters with the largest magnums and they are perfect for close
encounters. A scope is not a carry handle but I suggest a sturdy mount. I would be more worried about tacticool flimsy long cantilever than the QD capability to return to zero after mount / discount.
I have used all sort of systems, some are qd and so are not. But I kept only the good and sturdy. Weaver tactical scopes are tanks all japanese glass and tube. The 1-5 FFP runs you less than the trijicon or vortex.

Weaver Tactical Rifle Scope 30mm Tube 1-5x 24mm First Focal

Burris XTRII 1-5 also less but 2nd folcal plane like the Vortex PST that I do not like. The larger PST are much better scopes. Burris XTR 1.5-8 you should be able to find below 1K shipped.

 

[Podmonkey]

Okay, good stuff, good stuff l like those scope options. Can you give me some examples of the mounts you like? I insist on QD however. Focal planes I am not worried too much about, at the ranges I intend to shoot at, less than 400 yards, it shouldn't matter much.

 

[meketrefe]

see if you can find someone to try this one. I have not tried this but heard very good things from the 3 gunners....

SWFA SS HD 1-6x24 Tactical 30mm Riflescope | SWFA

 

[meketrefe]

Look at the price. I think swfa will do a price much and a few more things although midway is hard to beat in terms of customer service.
you don't like the scope when you get it and send it back no questions asked.

Leupold VX-6 Rifle Scope 30mm Tube 1-6x 24mm MultiGun Custom Dial

Wait until you have the scope to decide on the mount.

 

[Podmonkey]

Okay so say I have the scope, what am I measuring/ checking for, how do I match that up to the ideal mount?

 

[meketrefe]

you want to measure for both eye relief and height standing, seating and also prone.
Take your time. This is like measuring for a suite. If you have some rings around to get an idea great
othewise you can stack up coins and use some masking tape to put the scope in different positions.
you do this a the same time you find out your ideal LOP, comb height,etc...
whatever feels good to you. The rifle and the scope need to fit YOU and not the other way around.
People buy whatever they send them and they end up all stretched up and out or hunched down.
you have a unique opportunity to make the rifle or carbine your own!
.
makes sense?
..
It might be wise to move this discussion to another thread so we don't take over the OPs thread.
I will look for a tutorial to see if anyone is mounting a scope properly and share it. If I don't find one I will make one.
...