Scope mounted too high
How does a scope mounted too high affect bore sighting with the muzzle mounted instrument?
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eh, it will be off vertically. I wouldn't worry with regards to bore sighting.
Actually shooting and getting good groups, etc? Lower rings or a cheek piece or a new stock. You can't get good groups with an inconsistent sight picture (irons or scope) and to get a consistent sight picture you need good anchoring, which means good cheek contact, etc. Not to mention the potential parallax induced errors, especially at longer distances0 -
My experience with various optical or laser bore sighters. Are that they just get you close to the bulls eye. You actually have to fire, at a target on a range, To get the rifle, as precisely sighted in as possible.
If your scope rings are to high. Either get lower ones. Or a wrap around cheek pad, to compensate. For the higher line of sight.0 -
The scope can be mounted high as long as you get it sighted in, but if you cannot get a good cheek weld with the stock you cannot consistently get your eye in the same place relative to the reticle and you will not get consistent accuracy. 0 -
If you play with the ballistic programs you can see the trajectory effect with different scope heights above/below the standard 1.5 inches.
I use a roofing felt cap on a tree at 25 yards and look down the bore. I also use the calculated table from the program and check to see how close it matches my load in my rifle at say 2 or 3 data points. You can use the chart to figure out the best zero for the kill zone on your critter say +- 4 inches from the point of aim.
I have no clue to the elevation answer to your question, windage should be more or less correct.
Some scopes require high mounts.0 -
Personally I do not like putting ANYTHING into the muzzle/crown end of my firearms. Yes, I do realize that most spuds are made of a softer metal, but that still makes me cringe.
The collimator you speak of works well if the one using it knows what they are doing, regardless of ring height. For see thru scope mounts(and some extra high rings), you might not have enough adjustment in your scope to hit the zero grid on the instrument, but that is ok, as you really do not want to. You will want your crosshair to be slightly above the zero line.
Any scopes mounted overly high, I suggest starting at 25 yards, and working out to at least 100 yards in 25 yard increments, to keep your hits on the paper. The sight height(center line of optic, to center line of the bore, does have an effect on the position of your trajectory curve for any given load.
This said, I have been gunsmithing since I was 16(almost 54 now), and yes I do use a collimator at customers request. I have gained enough knowledge of cartridges, versus sight height, to usually get the firearm/sight combination very close to dead on at 50 yards.
For a collimator to work properly, the scope must be mounted square to the firearm...not the shooters eye. So...use your levels when mounting your scope, or use a level on the firearm, and a plumb line for the scope.0 -
don't even try to make the crosshairs match the boreline if using a laser boresiter.
I mount scopes on lots of AR type rifles where the scope is 1 1/2" (+/-) above the boreline. Aligning the scope approximately parallel to the boreline will get you on paper which is all a boresiter is meant to do anyway.0 -
quote:Originally posted by Mobuck
don't even try to make the crosshairs match the boreline if using a laser boresiter.
I mount scopes on lots of AR type rifles where the scope is 1 1/2" (+/-) above the boreline. Aligning the scope approximately parallel to the boreline will get you on paper which is all a boresiter is meant to do anyway.
In order to get into a scope on an AR platform, the C-T-C is more like 2.25-2.50 inches...unless you have no cheek bones.0 -
When I mounted a scope on my AR15 M4 Tactical Solutions 22LR upper, I couldn't use the collimating bore sighting tool or the laser bore sighter because it ran out power. So I just mounted and aligned the scope reticles and mid range adjusted the elevation/windage turrets and sighted it in at 25 yards to get on paper and then shot it at 50 yards and made some adjustments and went back to the 25 yards to see their effect - an iterative process until I felt I knew where the bullet's trajectory intersected the scope's line of sight. Planned on using the rifle for squirrel hunting and sometimes very close shots are taken when the bullet trajectory is below the scope's line of sight resulting in a miss or worst a wounded squirrel. I know with high mounted scopes there is a chance you run out of elevation adjustment and the bullet's trajectory remains below the line of sight never intersecting the line of sight and you have to shim up the rear mount bases to angle the scope's line of sight down. Never liked having a scope mounted too high. 0 -
quote:Originally posted by spirits
When I mounted a scope on my AR15 M4 Tactical Solutions 22LR upper, I couldn't use the collimating bore sighting tool or the laser bore sighter because it ran out power. So I just mounted and aligned the scope reticles and mid range adjusted the elevation/windage turrets and sighted it in at 25 yards to get on paper and then shot it at 50 yards and made some adjustments and went back to the 25 yards to see their effect - an iterative process until I felt I knew where the bullet's trajectory intersected the scope's line of sight. Planned on using the rifle for squirrel hunting and sometimes very close shots are taken when the bullet trajectory is below the scope's line of sight resulting in a miss or worst a wounded squirrel. I know with high mounted scopes there is a chance you run out of elevation adjustment and the bullet's trajectory remains below the line of sight never intersecting the line of sight and you have to shim up the rear mount bases to angle the scope's line of sight down. Never liked having a scope mounted too high.
Not familiar, with the Tactical Solutions 22 upper. If the rifling twist, is specifically made for the 22 LR cartridge? Your OK.
I bought a CMMG .22 conversion for my AR, and had a lot of aggravation. The rifling twist for the 5.56 X 45 cartridge, is way to fast for the .22 LR. My groups at 50 yards, looked like I was patterning a shotgun. Only tightened up. When I started using Aguila Super Sniper 60 grain bullets. Really surprised me! Didn't think the Aguila would even work in the AR conversion unit. Let a lone, be the most accurate cartridge fired from it.0 -
quote:Originally posted by rufe-snow
quote:Originally posted by spirits
When I mounted a scope on my AR15 M4 Tactical Solutions 22LR upper, I couldn't use the collimating bore sighting tool or the laser bore sighter because it ran out power. So I just mounted and aligned the scope reticles and mid range adjusted the elevation/windage turrets and sighted it in at 25 yards to get on paper and then shot it at 50 yards and made some adjustments and went back to the 25 yards to see their effect - an iterative process until I felt I knew where the bullet's trajectory intersected the scope's line of sight. Planned on using the rifle for squirrel hunting and sometimes very close shots are taken when the bullet trajectory is below the scope's line of sight resulting in a miss or worst a wounded squirrel. I know with high mounted scopes there is a chance you run out of elevation adjustment and the bullet's trajectory remains below the line of sight never intersecting the line of sight and you have to shim up the rear mount bases to angle the scope's line of sight down. Never liked having a scope mounted too high.
Not familiar, with the Tactical Solutions 22 upper. If the rifling twist, is specifically made for the 22 LR cartridge? Your OK.
I bought a CMMG .22 conversion for my AR, and had a lot of aggravation. The rifling twist for the 5.56 X 45 cartridge, is way to fast for the .22 LR. My groups at 50 yards, looked like I was patterning a shotgun. Only tightened up. When I started using Aguila Super Sniper 60 grain bullets. Really surprised me! Didn't think the Aguila would even work in the AR conversion unit. Let a lone, be the most accurate cartridge fired from it.
Proof that, yes...you can over stabilize a bullet...or spin it beyond its rotational strength. Friend tried using 40 grain TAP rounds in a 1 in 7 twist M-4 style upper. It was putting down odd looking 8" groups at 100 yards...and some were not even hitting, or even getting to the paper(they were coming unglued in mid flight, because of the thin jackets. Put some 69 grain match bullets in that same rifle, and it became a hole cutter at 100 yards.0
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