Sniper & Sharpshooter Forums banner

41 - 60 of 93 Posts

·
Registered
Joined
·
6,268 Posts
ok, let me ask you this. Why do some shooters use anti cant bubbles on either their rail or scope? Despite all the squaring up that is done, once you put a human being behind the gun, they unintentionally induce some cant into the system. Don't believe me? Next time you're at the range/match and someone has one of these anti-cant bubble levels on their gun, look at it and see if its level when they are shooting AND hitting the target. 9 out of 10 shooters wont be any where near level. People can and do induce cant into a mechanically squared gun, some more than others, some not at all, even when utilizing sound fundamentals and body position.
I didn't disagree with this. Never have. Sure, many shooters cant their rifles during a match. Doesn't mean they SHOULD.

You use the above as proof, and say you should let the rifle be canted, and mount the scope level to the world... if that's whats comfortable.

I disagree. Plain and simple. I say you should mount the optic and rifle level together, and then the shooter needs to keep it level.
At this point, this competitor "cleaned" the stage which included 1.5 MOA targets out to 800 yards...
... and as I said, the effect is more noticeable as distance gets past 1000yds. Also, holding a rifle canted that has a leveled optic is one thing, dialing in a firing solution for an 800yd target when the erector is not square to the rifle, and then holding your rifle canted is entirely another.

Level reticle, level erector, level rifle, then let the shooter do his best to keep the kit level when firing. That's my position. You say let them hold the rifle naturally and then level the optic. Well suppose they switch to their non-dominant side? I bet their "comfortable" position of canting the rifle just went away. Or suppose they get into an awkward position? How they had it canted will change. Yet in any position, with little effort, the shooter can get that rifle straight up and down if he so chooses. The fact that the people you compete with don't use their level's and still get hits to 1200yds doesn't surprise me. That fact does not automatically make me want to ignore keeping the rifle straight up and down to gravity, knowing that my optic is directly in line above it.
 

·
Registered
Joined
·
54 Posts
You use the above as proof, and say you should let the rifle be canted, and mount the scope level to the world... if that's whats comfortable.

I disagree. Plain and simple. I say you should mount the optic and rifle level together, and then the shooter needs to keep it level.
Clearly you are not reading my responses fully and or you are not comprehending them. No where have I said the rifle should be canted.Please refer to my previous post (#32)where I specifically asked that you go back and re-read the sentence where I specifically stated I do not dispute squaring the rifle and scope. Also please note that 1200 yards + was the longer distance, 800 yards was the distance the target was at for that specific picture. The same competitor had no issues at distances beyond 1000 yards while shooting in a similar manner. I am not advocating shooters to cant, I am saying some people do it unconsciously,even if to a small degree.

You also did not answer my question on how a person would correct for a canted reticle when the rifle and scope are known to be square but the reticle appears canted when the shooters is behind it. What is the fix?
 

·
Registered
Joined
·
3 Posts
Don't mean to but in on this but when I mount my scope to my rifle I use my bipod to minimize any induced cant I may put into it with my body.
I level my rifle, scope, mount and when I have every thing aligned I mount my bipod and lock every thing down then recheck.
I have used this method since Nam where I was a sniper-point man and it has served me well.
With this set up I have a confirmed kill at 1280 meters and have made many unconfirmed shoots that were longer.
Greg
 

·
Banned
Joined
·
2,249 Posts
Uh-oh.. We are having a Greg REVOLUTION HERE! Thats 3 Gregs in this little post / biggest penis competition...

BTW, I think the Gregs are winning...
 

·
Registered
Joined
·
6,268 Posts
You also did not answer my question on how a person would correct for a canted reticle when the rifle and scope are known to be square but the reticle appears canted when the shooters is behind it. What is the fix?
I correct that by sending the scope back. If I level my erector/turrets to the action, and the reticle is crooked, I send it back to the manufacturer until they get it right.

Let me see if I got a good lock on your position here.

You said earlier to shoulder the rifle in your normal shooting position, and then level the reticle to gravity by using a plumb bob, and lock the scope down, even if the shooter is canting the rifle while this is happening. You specifically stated that you should "leave the cant."

the very small amount of cant used for comfort is better left in place and the scope leveled after to the ground
That can only be interpreted that you are saying it's OK to mount a scope leveled to gravity on a canted rifle.

Is that indeed your position?
 

·
Registered
Joined
·
54 Posts
Let me try and simplify this and make it clear. The erector/turrets should be level to the action so that when you dial in elevation it is level with/moving along the plumb bob line or other vertical measuring means in the world as it moves up through its range of adjustment.
 

·
Registered
Joined
·
6,268 Posts
I agree with your above statement, as that's what I've been saying all along. Rifle level, erector level, reticle level. Your statement below doesn't say that however. What am I missing?
the very small amount of cant used for comfort is better left in place and the scope leveled after to the ground
 

·
Registered
Joined
·
54 Posts
Unless your stock/chassis butt can compensate for it, leave the cant in. Some people find that there is a perceived cant in the reticle either due to their eyesight, the scope reticle being slightly off or due to their particular body type when they shoulder the weapon. Vertical tracking of the erector to the world as it is moved through its adjustment is what is preferred despite the cant.
 

·
Registered
Joined
·
99 Posts
I'll butt in from a competition sporting clays perspective. For a rifle stock to be optimized to a shooters body the but stock will be canted. That's just the way God designed the shoulder pocket. Allowing this natural cant to occur is a good thing and allows for the shooter to better manage recoil and helps natural point of aim. However we Shooters want are o/u barrels and sighting pictures to be plumb to gravity. With applying this to my relatively new pursuit of long range shooter I find it is most comfortable to hold the rifle in almost every position (prone, siting, kneeing, repelling, etc) in a canted position. But you also want the scope and barrel to be on the same plane.

The solution is proper gun fit. I see a lot of talk on this forum about proper-bedding, free-floating, stock stiffness, etc. but not fit. With the exception of check-weld. This is just one of the many important aspects of fit. And from a Shotgunning POV can only be addressed with proper Length of Pull (which most solutions here are to move the scope forward or backward, which is sort of wrong, cant and offset. Only once LOP, cant, drop at heal, and cast on/off have been addressed should cheek weld be addressed. There's been books written over this. But if precision shooting is trying to eliminate shooter induced error even slightly muscling a canted gun level will introduce error. The solution is installing a fully adjustable butt-plate on your rifle so you can have the recoil pad in the optimum shoulder pocket and both the scope and rifle can be perfectly level. This is why $700 Manners/Mcmillian stocks are fully adjustable. Graco at Brownells this is an example of what we shotguners do to fit our guns perfectly to ourselves. Fit your gun, then level your scope and bore.
l_352000002_1.jpg
 

·
Registered
Joined
·
6,268 Posts
Outstanding contribution their rmdaily. I agree completely. If you can achieve perfect fit and comfort without actually canting the rifle, by canting the recoil pad, I'm all for it. However, for a true tactical rifle, you end up ensuring that your rifle can only be fired from your dominant side. That's not in keeping with the discipline in many cases.

I'm always a fan of having a rifle setup perfectly to the shooter, however, it should be noted that the stock/shoulder pocket interface when standing shotgunning, is entirely different than when prone. While you are 100% correct that muscling the rifle to eliminate cant will result in problems, it is not a prerequisite that you must be "comfortable" to achieve proper NPA behind the rifle either.
 

·
Registered
Joined
·
3 Posts
I have leveled the gun; rail, mounts, and scope. Have I gone to far with all that?

I have also checked my eye relief at each in crease with parallax. In doing all this I go to the range and zero. Once zeroed the rounds begin to wonder. I check to ensure everything is tight and start over. THEN frustration. I have gone through the hole process again and will be heading to the range early next week. Are there any tips out there?

Or is my scope done?
 

·
Registered
Joined
·
6,268 Posts
If everything is tight, and your POI is wandering... then it's either the scope, or the rifle. Often a poor action/stock bedding interface can cause that.

Easiest way to test is to replace the scope with one of known pedigree, and test again. If problem goes away, it's the scope. If problem persists, then it's the rifle.
 

·
Registered
Joined
·
3 Posts
Thanks. I don't have another scope handy. My boy looked at me like I hand a third eye. I did have one of the screws let go on the scope ring. Busted the gun back to basic mounts and new rings. a $100 bucks is better then a new scope for now. At least I'll know what it is now or too start the saving. Just hate having a gun down. Bothers me. Thanks for info Orkan, I just don't have anyone around here with the same interests as my self to borrow one. Cheers
 

·
Registered
Joined
·
2 Posts
What Orkan is saying is true.

See, no misunderstanding... I thought that's what you were saying all along. ... and I completely disagree. ;)
However; you have to realize that the scope body is not moving on the mounts when the turrets are moved, but it is the internals that are moving.
The 2" difference between the scope plane and the bore plane makes a slight difference geometrically....
But the biggest effect I can see is the dynamics of the barrel while the bullet is traveling down the bore. If the mechanics of the barrel/action/recoil lug/stock introduce a vertical deflection in the barrel vibration patterns, then a vertical to bore reticle alignment is important. If other factors introduce a horizontal vector to the barrel vibration, then adjustments of the vertical turret may show horizontal deviations in POI at long range ( 1000 yards or greater). Barrel vibration patterns can change with different bullets and loads, and some rifles seem to have odd horizontal changes in POI with different bullets. Finding a bullet / load that works consistently at 1000 yards, tuning the rifle - scope system to that load, and using reticle/turret techniques that work with that system is a process best approached in a systematic manner.
 

·
Registered
Joined
·
278 Posts
In this photo you can't really tell if the stock is plumb with gravity. Does that even matter? I mean if you put a vertical level on the butt plate centerline, it might not be perpendicular to the horizontal line on scope rings. It is possible to rotate action within stock a few degrees within tolerances of action screw holes in stock. But as long as the shooter verifies the permanently attached bubble indicator on his scope is level when fired, it matches the mounted condition (vertical reticle plumb with gravity) and you should not introduce horizontal error on long shots. This assumes the scope is manufactured internally correctly so reticle moves on a vertical axis. Doesn't it make sense to level rifle by placing level across scope base before mounting scope? And would that same level show same result if placed across top of bottom ring halves once installed? Then once you place scope in bottom rings all you have left is to use a level on top turret or align vertical reticle on distant object known to be plumb (hanging weight) with gravity? I am getting ready to mount a scope in a few days and all this discussion is interesting. I know that with an action mounted in a stock, they may not be square due to manufacturing tolerances (butt plate perpendicular to aluminum bedding block?) and things like rotating action in stock. It seems the most important issue is aligning vertical reticle (understanding vertical and horizontal reticles are perpendicular) with gravity. The bullet will be pulled toward earth on that line. It is just luck if you happen to have a stock that is exactly square with that configuration. Seems the stock canting issue is relevant here: you must have a vertical reticle plumb with gravity to expect no lateral errors. How you determine when it is plumb with gravity is the question. I don't see how you could ever know at long distances without a level attached to scope. I use a level on my archery sight to assure my bow is not canted because the lateral error introduced at 50-60 yards can cause a miss vital shot on deer not moving. And when sighting in my bow I can easily think the bow is plumb but it is not. I am new here to long range shooting and wanting to learn. I can't tell the experts from non experts but see there is disagreement. Can someone please confirm my suspicion that the stock alignment with gravity is not that important and agree that leveling the base and confirming that on top of lower ring halves is the correct starting point. Then you align reticle with that? Thanks
 

·
Registered
Joined
·
278 Posts
sanginreaper: I am new to long range shooting but knowledgable about physics, and the principles involved in ballistics. I can write the equations to solve for trajectory given intitial conditions, drag coefficients, gravity, etc. I know that the positions of the projectile (bullet) in the vertical and horizontal directions are independent of each other. The X equation has nothing but X (horiz) variable in it like its initial position and the velocity in the X direction. The Y equation considers the intitial Y position (one of which is "how low below the centerline of scope is the bullet; perhaps 1.5 to 2 inches" and the relative orientations of the bore and line of site (parallel or 20MOA down). The 2 equations are both necessary but not solved simulataneously because you don't have X and Ys in both (or either). But you need the flight time to determine where it goes. So getting the VoY (initial velocity up) is the key needed first. The longer the shot, the higher the barrel is pointed above the line of sight so that as it travels across the earth gravity can bend it back down until it hits something. In other words, flight time from muzzle to target is determined by how fast the bullet moves to its target and that that time determines how long gravity can act on the bullet to pull it back towards the center of the earth. What I don't have is experience to know how these various initial conditions (mounting a scope on a rifle which is not made perfectly) affect the desired outcome of hitting your target at long range. I am old enough to know that experience is invaluable which is why I joined this forum. Experience is as important as knowledge. I don't have experience. My shooting has been limited to hunting situations where I sight in my Browning Stainless Stalker 300 Win Mag at 200 yds (about 1.1 inches high at 100 yards, And I generally don't have shots over 300 yards, where I might be 5-6 inches low. I am now setting up a rifle for shots to 1000 yards. I have a Rem 700 , 5R 300 Win Mag, Vortex PST Viper 6-20X50mm, a Nightforce steel 20 moa base coming and Burris XTR 30mm rings. I have discovered that my mass produced rifle is probably not perfect and anxiously awaiting mounting that scope and taking that first shot to see how well the barrel and action are aligned. I have learned from here that I need to determine if my 1 piece base needs to be bedded and will do that if necessary. The other issue has to do with what to align the scope reticle with? I don't think we can alter the squareness of the stock and action as that is determined by how they were made and how well they fit together. Once I get mine in a vise I am going to put a level on the base (once mounted to receiver) and check if the centerline of butt plate is perpindicular to the base (and the rings should be parallel to base). But it is what it is. As someone else said here, if you don't keep your rifle butt plate vertically oriented but had your reticle parallel to that line, what have you gained? You should expect lateral errors exacerbated at long distances. With humbleness I believe that having the reticle aligned with gravity (e.g. hanging weight in distance) is probably the most important thing and the further the better for smaller angular errors. Then when taking a long shot you must know that the reticle is aligned with gravity. I don't know how you could ever know w/o a level bubble attached to your scope. Now at some distances (and this is where experience comes in) it will not inroduce enough error to miss your target. I have shot deer at 360 yards w/o worrying about how aligned my stock was to action when mounting my scope. The discussion about canting the rifle got me thinking about these things. My guess is that if you cant your rifle the same everytime AND you made your reticle plumb with gravity when mounting scope AND you knew the cant was the same when taking a long shot , it should not matter. How you could know though seems impossible w/o a bubble OR the shots are not far enough yet to make you miss your target and you are repeatable with the same can't. Thinking about a bipod, I am assuming they let you rotate the rifle about the barrel axis (never had one - no experience) so that you can align the reticle plumb with graivty? I mean how level is the ground when you set up? I don't claim to know anything about long range shooting. I am here to learn. I am just trying to make sense out of the various discussion and reconcile it with what I know are basic principles. And I know experience is invaluable. When I was asking a surgeon IF he could fix my son (hole in intestine and he is fine now) at 10 years old, I did not ask him where he went to school, where he ramked in his class, etc. I asked him "Have you seen this before, have you fixed it before, Can you heal my son?" He had done it many times and said he could do it in his sleep (although I asked him to stay awake). It was then that I realized experience is invaluable. There seems to be a wealth of experience on this site for which I am grateful. I am an Engineer and have a Master's Degree but I realize that doesn't count for anything with regard to experience. I will keep reading these threads and soaking up all the experience. Thanks
 
41 - 60 of 93 Posts
Top