How to bore sight a rifle: McGyver style
Tonight I finally scored rings that were just right enough in height to allow both the objective and the eye piece to clear the guns 1913/Picatinny rail base.
They are cheap rings from Wal-Mart but it'sj ust a .22 and a high mass/heavy one at that so recoil should not be notable enough to require $50 a pair 'quality' rings.
So next thing to do was to mount the rings, then the scope on to the rings, and from there align the scope as on the X/Y axis and to lastly 'bore sight' it.
This latter item is what I'll cover in detail here.
To bore sight a rifle simply means to coarsely align the bore toward a target at a given distance, preferably one that is distant, and to from there align the scope as within it's rings to match that of the bore as has been 'sighted' manually by eye.
On a bolt gun such as what I'm working with there should be no magazine in the well (if applicable), clearly no ammunition in the gun nor anywhere within sight of the gun...and from there the bolt removed from the guns reciever.
Doing this on an semi-automatic rifle and/or one that when the bolt is removed does not allow direct view through the barrels bore will then require additional specialized tools not to be covered in this discussion.
Next is to place the gun in or on a _stable_ platform.
This platform optimally would be a shooting rest.
But seeing as I do not and never have owned such a device, alternative means had to be located and applied toward same net effect.
I used my kids life size stuffed 'Carl' dog!
With Carl placed upside on his back a top my dining room table braced on one side by the weight of the gun case itself and the gun seated between his legs at his chest area, I found myself with a stable and non-moving surface.
Sorry about the darkness but the dog is black, the gun is black, the scope is black....And I had all the lights on in two rooms at that.
From here I then walked to the far opposite side of my house at my kids play room wall & door.
Distance between points as measured from the door mounted target to the back of the scopes eyepiece was 42.5" which is a hair over 14 yards.
For visuals sake this is a half inch wider than a standard sized tennis court as measured from the net posts edge to edge. I very commonly use the tennis court as a point of reference toward shooting sports. The dimensions very often meet every application I find myself needing to relate against.
When bore sighting the further out in distance you can functionally place your target AND still be able to actually see it as through the bore of your specific gun, the better and more inherently accurate you will be as toward both getting your initial shots on paper and aligning the scope to that of the bore.
Oppositely the closer you are the greater the degree of variance and by that probability to be very coarse rather than fine in your sight in effort.
The way my current house is configured this is the longest straight shot view I have available on any of three floors.
I could have taken the gun outside to do this and greatly increased my range, but it was dark & cold outside. As well the bore of this gun is .22LR, which is TINY.
Out to a given distance the ability to actually see the target through the bore decreases at a point of distance. In my case had I gone another 5 to 10 ft. it would have been improbable that I'd be able to see the target.
Next I'd affixed to the door a target. It was a folded square of green material at 4" square.
I used green for sake of high visibility against what is a white door so that I could pick it up by sight while looking through the bore.
I'd made it 4" folded and square because I wanted clean demarcation of the targets edges as well the target needed to be small but not so small that i would be overly difficult to pickup through the bore.
Most people use a conventional sized target for this such as a 9" circle and that is fine, but remember the goal here is fine degree accuracy as rather than coarse guesstimating.
The finer you are here the less time you'll have to spend at the rage fine tuning the rig.
The sight 'target'
Shooters position view of the target as from normal shouldered shooting position, with gun remaining in rest
After this I installed the lower half of the sight rings being careful to_not_lose any screws toward the tops.
This took a little trial and error to best fit the scope with it's 40mm objective to both the rings in spacing length as well to that of the 1913/Picatinny rail for clearance and eye relief.
When I got it situated I placed the ring tops on and in an alternating opposite pattern
Once the target is set take your time to carefully align as best you can the bore of the gun _first_ toward best you can see/tell the middle of the target.
Considering the bore of this specific gun is so small I choose to reduce by half the size of the sight target. This will cut down greatly on my odds of inaccuracy.
Next you _carefully_ screw down with light torque the scope ring top halfs.
In my case each scope ring had two independent straps which worked out to two sets of two screws per base. With this I tightened down the outer most screws per base first at opposite positions. Then worked my way to the inner two straps opposite screws of those I'd tightened prior. I continued this pattern all the way around until every screw was finger tight light. Light meaning loose enough that the scope can be rotated but tight enough to keep the straps on.
Then while looking through the eyepiece rotate the scope _slowly_ to align the sight bars on a proper vertical and horizontal axis.
This step is important.
Tighten down your scope ring screws a final 1/2 to 1/4 turn but do NOT crank down on them. A little goes a lot.
Now align the bore of the gun using exclusively fine movements. It is very easy to miss the target altogether making gross sweeping movement of the barrel.
Once you pickup the target align the bore toward the center most area of the target.
At this point _do not touch_ the gun and now look through the eyepiece of the scope.
With the scope turned down to it's lowest magnification and the parallax set to the proper distance in yardage (mine was set to 15 yds.), the target will optimally be dead center in your cross hairs.
Of course real world nothing ever works out to be optimal. ; )
In my case the cross-hairs were just a couple about 1/8" high of center and dead square at the horizontal.
Optimally I'd have a bubble level installed to verify this but for the moment with these rings $10 rings I'm not going to invest the coin.
To verify I replaced the swatch of cloth with a 50 foot bullseye slow fire pistol target.
It has a 3" diameter black center ring on a field of tan.
View of the target from the shooters perspective
Looking through the bore once more to carefully align it I was able to pickup the ring which through such a tiny bore appears to be a black dot with a ring of white/tan around it.
Not touching the gun at all this is the view through the eyepiece via my cell phone as held from the right side.
It's not going to get any better than that!!!
No further activity required nor involved.
Next is to take the rig to the range and opposite my norm, shoot the gun off of bags to verify point of impact against point of aim.
Gun = Savage Mark II 'TRR' [No longer in production..Replaced by TRR-SR]
Note: same gun as above only without the not MA lawful threaded barrel.
Scope = BSA 'Sweet 22' 3-9x40 Adjustable Objective [No longer in production...Replaced by a much more expensive side parallax adjustment model]
Part Number = 22-39x40AOCP
Price = $49 on clearance at Dick's
Rings = Weaver 'Quad Lock' 1" diameter high height for up to 44mm objective lens
Part Number = 49047
Price = $8.99 MSRP at Wal-Mart