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scope/ bore alignment question

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rooshooter View Drop Down
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    Posted: September/12/2007 at 05:17
this maybe bit of a newbie question, nonetheless:

if i have found the mechanical centre of my scope, mounted the scope and found the crosshairs not on target straight up, and then adjusted with the dials to put the scope on target

...does that mean the scope won't be accurate downrange?
...is there something more i need to do to get the most accuracy out of the setup?
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Post Options Post Options   Thanks (0) Thanks(0)   Quote RONK Quote  Post ReplyReply Direct Link To This Post Posted: September/12/2007 at 20:43

 rooshooter, I've read  and participated in a few of your recent posts on this subject, and I think you've asked some good questions, but you still seem a bit bewildered by some basic concepts. If you will take the time to read, ponder carefully, and follow my advice, I'm sure we can get your rig shooting well.

 First of all though, we need to get something straight.You seem to be absolutely determined to get the most out of your setup, and that's great. We all do, to some extent. What you must not do is delude yourself into thinking that you are going to get a discount store rifle/scope/ rings /base/ ammo combination to shoot as well as a custom Windrunner with a PMIII on it. Just not going to happen, so if this is an entry-level rig, discipline your mindset to accept the limitations of that equipment or else be prepared to spend a LOT of money. To do otherwise is to waste a lot of time and effort.

  Okay, now that that's out of the way, let's determine what a reasonable expectation of performance  actually is. If I recall, you have a sporter- weight hunting rifle chambered in .223 Rem.and you wish to shoot kangaroos in the gourd at 200 to 300 yards. That right there is going to require an above average performer. Not unreasonable though. It will require good (probably handloaded) ammo, a good barrel, proper barrel and receiver bedding, and a crisp, fairly light trigger pull.

  Still with me? Good, because if your rifle isn't capable of good, consistent groups on it's own merits, it simply can't shoot well even if you mount a $3500 scope on it. If you have the honest confidence that your rifle will perform well and consistently, as judged by it's past performance or at least by the examination of a good gunsmith,mounting a scope and getting it zeroed is easy. Getting to that point is often a long road, though.

  I've typed too much tonight already ,so if you bear with me, I'd like to continue this tomorrow. Any criticisms of this post so far though are premature, and thus strictly forbidden...    ------    

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Post Options Post Options   Thanks (0) Thanks(0)   Quote rooshooter Quote  Post ReplyReply Direct Link To This Post Posted: September/12/2007 at 23:51
based on past performance i know my rig can shoot well. as far as what influences accuracy of the rig in setup etc is still a bit confused to me. please continue.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote RONK Quote  Post ReplyReply Direct Link To This Post Posted: September/13/2007 at 17:37

 

  Alright, I will. Thanks for bearing with me so far. I think the next step in your case is to set up a good work area, if you don't have one already. You need a sturdy workbench under good lighting and enough room to comfortably work around it. Ideally it would be overlooking a 500 yard rifle range, but that isn't necessary for the time being. One of the new rifle vises that gently but firmly hold guns for cleaning, boresighting and in some cases, even shooting, would also be very useful.There are several on the market, a search on the internet should get results. If you don't have one yet, sandbags can certainly be made to work with a bit of ingenuity and patience.

  Okay, now we gather our components together for a critical evaluation of compatability. Rifle. Scope. Base, with correct screws. Rings, with correct screws. Screwdrivers properly ground to fit the various screw heads perfectly. Many component manufacturers are going to supply Allen screw heads or Torx heads. This eliminates the screwdriver fit issue, and they usually supply the appropriate Allen or Torx wrenches with each base or set of rings you purchase. This is best, for a beginner especially.

  Here I need to start assuming a few more things and only because I can't be there helping you.  I hope the rifle is a common Remington, Savage, Winchester or something of that sort. Ruger and Sako and a few others have base provisions machined into the receiver which require proprietary rings. Nothing terribly wrong with that as they usually work fine, and they pose the advantage of eliminating bases, but they may also eliminate some ring options. Sporterized military rifles often have out-of-spec contour issues which sometimes create problems in getting the base to fit properly, although new factory rifles are certainly not immune to that problem.  AR-15 and AR-10 flattop platfoms are great, as they completely eliminate the need for bases in many cases.

   Again, I am assuming that your rifle is a bolt-action and that it is drilled and tapped for a base. The base must be made for the rifle you have. There should be 4 holes on the top of the receiver, two in front of the loading port and two behind it. They  should at least look like they are in line with one another and with the barrel. If you have a one-piece base, depending on the brand, it may mount up using only the front three holes. A two-piece base needs two screws in each base. Now set the rifle solidly in your vise or sandbags and get an assistant to give you a hand holding things steady. Use a little acetone to de-grease the receiver and the bases, as well as the screws and screw holes. Place the base on the receiver and check that the holes line up. The directions may or may not explain how to orient them, but generally it's pretty apparent when you set them in place. Sometimes it matters, sometimes not. It depends on the rifle and the bases. Check your screws to make sure they protrude through the base, but not through the receiver to interfere with the bolt function, etc. If everything looks good, put the screws in and snug them up good. Normally, we would have put Loc-tite on them first, but I think a dry run is in order here. It's not really a big deal to go back later and dismantle, de-grease , Loc-tite and reassemble everything. We need to make sure the whole system will come together well before we get too permanent just yet.

  I've got to go for now. Will check back soon...



Edited by RONK
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Post Options Post Options   Thanks (0) Thanks(0)   Quote rooshooter Quote  Post ReplyReply Direct Link To This Post Posted: September/14/2007 at 00:20
my rifle is a howa[apparently made in the same factory as weatherby] and made in japan. guaranteed to shoot 1 1/2" groups with premium ammo. so far the best i've done is about 1/4" 3 shot group at 50 y. i reload with remington 50g plhp. i have floated the rifle myself[with about a 3mm clearance all round due to the polymer stock which flexes a little] and have lightened the trigger[factory adjustable],don't know exactly how light but a lot less than factory. have weaver hinge rings and bases-have lapped the bottom half. haven't touched the bases-mounted by the guy at the gun shop.

hope that helps

please go on!
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Post Options Post Options   Thanks (0) Thanks(0)   Quote rooshooter Quote  Post ReplyReply Direct Link To This Post Posted: September/14/2007 at 00:22
currently have a simmons whitetail expedition

will be getting a new nikon 5-20-44 nikoplex
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Post Options Post Options   Thanks (0) Thanks(0)   Quote RONK Quote  Post ReplyReply Direct Link To This Post Posted: September/14/2007 at 19:36

 

  I think you are well on the way to putting together a GREAT rig. Achieving quarter inch groups at 50 yards is a very good sign that your rifle will probably be able to do marvelous things way out there, and is also proof that you know how to shoot it well. Good work so far!

  Alright then, the bases are on tight, and you've snugly mounted the lower ring halves onto said bases, with the large thumbscrews both on the same side. I'm right-handed and put them toward the left side, but it really doesn't matter. Personal preference. (The magazines of my rifles load from the right so I want less clutter there.)  Push the ring lower halves forward, (toward the muzzle), as you tighten them down. This assures that they contact the recoil bosses on the bases properly from the start. If you don't do this, the recoil will do it for you later anyway, but with a bit of movement, which we really don't need to add to the equation.  If you failed to do this before you lapped them, you may wish to loosen them and do so now.  When they are tight again, (and forward), lay the lapping bar into the cradle and take a few more careful strokes, in full contact with both lower ring halves at all times. When you are quite sure that you have lapped away any high spots, clean the rings up with mineral spirits or acetone. Don't get any on the stock.  Set the scope into the cradle, and check it for fit by alternately pushing downward on the tube directly above each ring lower half. There should be no perceptible wobble. You'll be able to tell if it feels right or not. If not, get the lapping bar back out.

  O.K., now put the scope about where you want it, (objective bell forward, elevation turret up), and  slide the top ring halves over the tube and into place on their lowers. You mentioned Weaver "hinge" rings by which I think you are referring to the ones with the two screws on one side and a lip on the other, which engages the stamped steel top ring halves.  Correct?  Good.  Now place the screws into the holes, (two per ring.), and finger tighten them, but not enough to prevent the tube from sliding with a slight bit of friction.  Slide the tube back and forth as necessary to obtain correct eye relief. Do this outdoors, with your shooting or hunting clothes on, as this will affect this adjustment by positioning the rifle further from your eye. Try it at all magnifications, and when you get it right, put a reference mark on the tube where it contacts a ring so you can find it again later. Hopefully you have gotten to this point without a bell or the turret preventing correct fore-aft location. If not, you can get offset rings or bases to correct that, but it can be a hassle finding them. You may, however, be able to reverse the bases to do the same thing. Not sure about the Weaver bases for the Howa....

  I'm done for now buddy.Catch ya later.



Edited by RONK
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Post Options Post Options   Thanks (0) Thanks(0)   Quote rooshooter Quote  Post ReplyReply Direct Link To This Post Posted: September/14/2007 at 21:25
ok i did slide the bottom half of the rings forward, but i think that was after i lapped them...something i read on on of chris' posts.

as for the relief, i'm not sure it's that critical to me as 99% of my shots are taken leaning on the roof of a ute with my bipod, so the relief is different than normal anyway. i suppose based on what i've just said, i could set up the relief to match that scenario.

cheers though, i really appreciate your input so far. please keep it coming if theres more.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote RONK Quote  Post ReplyReply Direct Link To This Post Posted: September/14/2007 at 23:04

 

  Well, I'm back for a few minutes. Where were we? Oh yes,  just finished establishing correct scope position/eye relief. Now comes the part where you will temporarily despise yourself for trying to save money by buying this type of rings.  They have an installation quirk which can drive you crazy if you are not very patient. What happens is that as you tighten them down, the top ring halves grab onto the scope tube and rotate it as you tighten them. This makes the reticle tilt in the image, which looks stupid and causes zeroing problems.What you have to do is start to tighten them with the tube twisted slightly the opposite way and hope you end up straight when tight. Trial and error, sometimes over and over again. Don't get discouraged though, you'll get it eventually. Go slow, tighten the screws gradually alternating one to the other, all four, until all are snug. Remember that the lowers are aluminum, so don't over-tighten or you will strip the threads. You can use any of the various levels or levelling systems on the market to tell if your reticle is straight, but just looking at it repeatedly and critically, and having a few friends do the same will get you very, very close to perfect. Keep in mind that you are trying to get it level to the rifle, and nothing else.  I concentrate on the bottom of the verticle crosshair to see if it seems to be pointing down through the center of the rifle. It sometimes helps to remove the bolt and move back a little as you do this. Once again, you'll know when it's right.

  Now we must address an issue you brought up in previous posts and in other threads, and that is the finding of your scope's mechanical center. You indicate that you have done so already. This is good to do, but only if you have some means of adjustable rings. You do not have adjustable rings, which we will soon determine to be a problem, or not. Maybe we'll get lucky, maybe you'll be buying a set of Burris Signature Zee rings and throwing away your lapped Weavers. (Or at least doing some creative shimming).We'll find out soon.

  Alright. Everything is looking good, straight, square, proper eye relief, all screws tight but not stripped. If your scope has an adjustable eyepiece now would be a good time to focus it, although I really should have had you do it before you put it on the rifle. (Sorry, Man, I forgot.) Anyway what you need to do is look at the sky or a large, distant, light colored surface. A white wall  across a room is ok, but daytime sky is better. Throw the gun to your shoulder toward sky or wall. The reticle should appear in clear, sharp focus instantly even if the wall isn't. Most decent scopes have an eyepiece  with a lockring that allows this adjustment to your eyesight. Loosen lockring, turn eyepiece (ocular bell) until focused, and re-tighten lockring. Don't allow your eye time to focus on it either. It must appear sharp instantly.

   Once that is done, (and it shouldn't have changed your eye relief, but if it did, you'll have to back up a couple steps and get back  to here.),the next step is bore-sighting.

 Tomorrow. Goodnight !

 Edited to add: I didn't see your last post until i had typed and sent this one. I'll catch up in the morrow.



Edited by RONK
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Post Options Post Options   Thanks (0) Thanks(0)   Quote rooshooter Quote  Post ReplyReply Direct Link To This Post Posted: September/15/2007 at 07:56
ok you may have read in some of my other threads that the rings came with the rifle. they're crappy and meddlesome yes, but they work. once i get my new scope i may get new ones to compliment it's beauty.until then...

i have bought a line level from a hardware store which i have used to get the action horizontal followed by the rings. theoretically the rings should now be perpendicular to the action and if the holes in the receiver are where they should be[pretty good chance based on previous performance], central to and vertical over the bore.

now about the mechanical centre issue. no i don't have adjustable mounts but i have boresightrd the rifle at 100y already. now assuming the rifle sights in at that range, i should be good to go right??

i only brought up the mechanical centre issue in previous posts because i read on this forum that getting as close as possible to zero without using the scope's adjustments, means that the lenses in the scope aren't canted or twisted or anything and are more in alignment with one another giving a better picture. is that correct? or is it simply to maintain adjustment up one's slieve should one ever need it.

over!
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Post Options Post Options   Thanks (0) Thanks(0)   Quote RONK Quote  Post ReplyReply Direct Link To This Post Posted: September/15/2007 at 12:03

[QUOTE=rooshooter]ok you may have read in some of my other threads that the rings came with the rifle. they're crappy and meddlesome yes, but they work. once i get my new scope i may get new ones to compliment it's beauty.until then...

i have bought a line level from a hardware store which i have used to get the action horizontal followed by the rings. theoretically the rings should now be perpendicular to the action and if the holes in the receiver are where they should be[pretty good chance based on previous performance], central to and vertical over the bore.

now about the mechanical centre issue. no i don't have adjustable mounts but i have boresightrd the rifle at 100y already. now assuming the rifle sights in at that range, i should be good to go right??

i only brought up the mechanical centre issue in previous posts because i read on this forum that getting as close as possible to zero without using the scope's adjustments, means that the lenses in the scope aren't canted or twisted or anything and are more in alignment with one another giving a better picture. is that correct? or is it simply to maintain adjustment up one's slieve should one ever need it.

over![/
QUOTE] 

 

 Well, the real reason to find the scope's mechanical center is as you say, to get the system zeroed up as close as possible, by using only EXTERNAL adjusment means, such as shimming, windage-adjustable rings or the Burris Signature system.  I am unaware of any elevation-adjustable rings other than the old barrel-mounted Lyman type target scopes that had no INTERNAL adjustments. With them, all zeroing was done by moving the scope tube around, pointing it in different directions as needed. Read that last sentence again, because that is really in essence what you are trying to do when you use adjustable rings to get close to zero,after you have set the scope's wind and elevation at the center of it's full range of travel (mechanical center).  Of course what this accomplishes is that your scope tube is now fairly lined up with the bullet's path, and it will require you to use very little of the scope's INTERNAL adjustment to fine tune it. This leaves you with the full adjustment range in all directions, which is good,  but more importantly it keeps the scope's optical qulities centered up as well. Center is generally where the lens quality is the finest, allowing your eye to percieve a crisper image than one in which the image  is bounced from one edge to another all the way through the system. 

  Of course in a perfect world we wouldn't need to go through all that, because everything would be engineered and contoured and drilled and tapped and machined pefectly. Sometimes it actually is, more often it is not. Usually it is fairly close and we don't need to do much to make it work. I would say that if you have at least ten or fifteen minutes of adjustment left in any direction, after boresighting, you are probably good to go to the shooting range and sight it in. If I get flamed for anything on this thread, it will probably be that statement. Obviously it would be best to get pefectly centered up externally, but I don't know that you need to go that far to shoot well at 300 yards, especially on a budget. You can do it for free by shimming with beer can shims, but it can be a big hassle involving some trial and error and lots of disassembly.

  O.K., I think that wraps up my essay on the subject, barring any follow-up questions, which of course I would love to answer. I sincerely hope that you found some of this helpful. Please keep me posted on your results, rooshooter.

 

  Any other opinions- Flame Away !!!

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Post Options Post Options   Thanks (0) Thanks(0)   Quote RONK Quote  Post ReplyReply Direct Link To This Post Posted: September/15/2007 at 12:24

 

 I would like to add that while Weaver rings and bases are inexpensive, and prone to some of the limitations we discussed, there is nothing "crappy" about them. The do what they do very well. They are light, strong enough to endure normal use by a halfway careful hunter. They hold scopes on heavy kickers surprisingly well. They are available in more  ring-base combinations than anything else I am aware of. Oddball firearms usually have a Weaver solution to mounting problems where no other manufacturer can help. They have quirks, they are not extreme-duty tactical, and they probably don't win many beauty contests. They do work very well most of the time. I hate to see them get sold short...

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Post Options Post Options   Thanks (0) Thanks(0)   Quote rooshooter Quote  Post ReplyReply Direct Link To This Post Posted: September/16/2007 at 00:40
thanks ronk. most helpful. i will keep you updated as things progress, especially after i get my new scope. it's tough waiting as you probably well know, but until then...
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Post Options Post Options   Thanks (0) Thanks(0)   Quote RONK Quote  Post ReplyReply Direct Link To This Post Posted: September/16/2007 at 09:32

 You're welcome. Keep us posted on your progress. Just as an afterthought, there's nothing to keep you from mounting up an old scope as I have outlined above.  It will give you something to do while you wait for the new one to come in. More importantly, it will show you how well everything lines up when it is all together. If you are centered up EXTERNALLY with the old scope, you will be with the new one as well, when it comes in. All you will have to do at that point is remove the upper ring halves, remove the old scope, focus the eyepiece on the new one,set it into the cradle, slide it fore or aft for your desired eye relief, twist it straight up und down, tighten the upper ring halves, and go sight it in!

  If  you need to shim anything or go with different rings, you will have bought yourself some time to do it. Once you have your lapped cradle in good alignment to the bore, don't move your rings around. If you need to dissassemble them further, be sure to put each individual piece back in the same base slot, etc that it was in before disassembly.

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Post Options Post Options   Thanks (0) Thanks(0)   Quote rooshooter Quote  Post ReplyReply Direct Link To This Post Posted: September/17/2007 at 05:02
how can i get the scope lined up extrenally without adjustments? is shimming the answer?coke can? if so how is it done and is it worth doing?
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Post Options Post Options   Thanks (0) Thanks(0)   Quote RONK Quote  Post ReplyReply Direct Link To This Post Posted: September/17/2007 at 20:56

Originally posted by rooshooter rooshooter wrote:

how can i get the scope lined up extrenally without adjustments? is shimming the answer?coke can? if so how is it done and is it worth doing?

 

 With the rings you have, shimming is your only practical option, and only for fairly minor elevation corrections. The standard practice for years has been to cut shims with a scissors from an aluminum pop can, sliding them under the appropriate base until the correction has been made to satisfaction. Commercial steel shims are available, and much preferred to aluminum. Do not shim between rings and scope tube. Won't clamp it properly. It's probably worth doing only as an emergency solution to get a rifle up and running on short notice. I personally believe that the Burris Signature system has made shimming virtually obsolete.  I HIGHLY recommend it for solving almost any alignment problem. Requires a set of new Burris Signature Rings and a few sets of offset inserts though. Maybe 50 bucks?

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