Bore Sighting and Maxed Out Elevation

20 moa corresponds to 5 inches at 25 yards. Assuming the scope is optically zeroed, you would expect the bore sight to be 2.5 inches above the reticle. Knowing that the scope dial adjusts the bore sight, you would want to dial down to get the bore sight about an inch below the reticle at 25 yards, or about bang on at 50. The target you show in your first post seems about right for 25 yards.
 
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Buck1950 said:
Nice looking setup. Looks like you could go lower with rings unless you need the height to get the relief on the scope. Hope you get this sorted. Guntech always has good advice.
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Thanks man. Ya I think the rings could come down a bit….but not much. They need to be up there for comfort and relief. I think I just need to send some lead down range and see what happens.

I have a friend who does PRS competition stuff who’s gonna come look at it tomorrow. I will report back once I figure things out.
 
Your rings are too tall. Get some medium rings. I had this. My riser was to tall and the elevation maxed out. Lower rings fixed it. You probably will be on paper without bore sighting.
 
You are shooting almost 2 inches high in that scenario. Are you moving the crosshairs in the right direction? They should move up the target to lower the elevation. If the rail is 20 moa the centre setting on the scope should put the reticle about 2.5 inches low on the target given your elevation above the bore. So you would have to move the reticle up the target to the bull to zero. That's down adjust on the scope knobs. So it looks like you need 10 moa of down adjustment to zero at 25 yards. If I understand your first post right you want to put the retical 2.5 inches above the bull that the bore is pointed at. But that would be 30 moa of down adjustmentwith your rail and put you 2.5 inches low at 25 and about a foot low at 100. If you want to zero at 25 you have to put the reticle and the bore at the same e place at 25 yards
 
You don't say what calibre your SIG is, so I assume it's .308 or 6.5.
I also assume your scope is leveled to the rifle scope base.
Confirm scope ring torques and scope base torques.

Zero your rifle at 100yds.

Remove your bolt. Site down the barrel and adjust your rifle position so that the bullseye is in the centre of the bore.
Adjust the crosshairs for windage and elevation to the bullseye.
Confirm that your boresight and crosshairs are centred as best as possible on the bullseye.
Replace the bolt and fire 3-5 backstop rounds (not on target) to reduce any cold bore induced error.
Then, with a warmed up barrel, fire 3 or 5 deliberate rounds for group. Crosshairs on the bullseye for each shot.
Measure the distance (elevation and windage) of the centre of that 1st group from the bullseye.
Adjust the scope windage and elevation to match the measurements taken to move the centre of the group onto the bullseye.
Fire a second group (minimum 3 rounds). Make scope adjustments again if necessary.
Keep repeating until the centre of the group is centred on the bullseye to your satisfaction..
Reconfirm scope ring and scope base torques and also that scope is still level once you have zeroed.

My 2 cents.
 
Tamer said:
Here’s a pic of the rifle in case you guys care.View attachment 832471
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That cantilever
mount isn't doing you any favors. Those are typically found on AR or other flat top actions. Get yourself a pair of scope rings and lower that scope to the bore.

Look at this image and imagine how your too high scope increases the vertical adjustment required along with a 20moa rail
 

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Well, I had the scope looked at today by a professional and he told me it's buggered. No wonder I was getting so frustrated. Anyways, I bought the whole package off the equipment exchange so I'm hoping the seller is a good nut and not gonna take advantage of me. I emailed him a moment ago....so I'll let you know what happens. Thankfully, a friend had a spare NightForce to lend me for hunting season.

Anyways, thanks for all the help gents.
 
Tamer, thats a shame cause they're good scopes, mine have lasted about 4-years but just on 22s. Tho not in the same league as a NF. I've heard of others with troubles with those Covenants, but only the 'newer 5 and 7s.
 
Buck1950 said:
Tamer, thats a shame cause they're good scopes, mine have lasted about 4-years but just on 22s. Tho not in the same league as a NF. I've heard of others with troubles with those Covenants, but only the 'newer 5 and 7s.
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Ya well...I guess we'll see. When I met up with him to do the transaction, he handed me the rifle to look over and he mentioned he's had a hard time keeping a zero with the scope. That was a bit of a red flag. But "hard to keep a zero" and "impossible to zero" are two very different things. Hopefully he has the integrity to make things right.
 
But you are trying to bore sight your scope 10 moa low, you still have a problem. You need 20 moa of down adjustment to hit that red line with your setup, more or less
 
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Ring height can be a dicey proposal.

The scope as a general rule should be as low as possible, a couple of sheets of paper clearance between the barrel and objective.

You'll get the full advertised elevation adjustment out of your scope this way.

However even knowing that some people use high rings for shooting comfort, like the rings on the thread starters rifle.

Even if the scope is not malfunctioning using rings that high might not give yiu the adjustment you require.

Also as odd as it sounds if you use windage adjustment on the scope it takes away some of the available elevation adjustment.
 
Just a thought, Tamer. The spec for that scope was 40MOA and if you counted to 56-7 maybe the prev owner 'over-cranked it' to have that much. That'd 'bugger' many scopes. As I said, I've got 2x those scopes and just y-day shot sub-MOA with my $330 Sav B22-FV, using SK-RM and the Covenant-4. Also, it shoots 1.5" at 100.
 
Tamer said:
Well, I had the scope looked at today by a professional and he told me it's buggered.
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A professional what? What did he say is "buggered"?
If I understand, you haven't even shot the rifle yet. You've got the cart a mile ahead of the horse with a bunch of theory and observations and reactions to.....which may all be irrelevant. Get outside and shoot the thing.....then if you have an actual problem it can be real-world remedied.
 
Any chance who ever sold it has the box or receipt? There was a time when these had lifetime warranty and it was written on the box. I had one refunded two years ago because the windage would adjust in one direction and it lived it's whole life on a 223 bolt gun.
 
Tamer said:
Ya well...I guess we'll see. When I met up with him to do the transaction, he handed me the rifle to look over and he mentioned he's had a hard time keeping a zero with the scope. That was a bit of a red flag. But "hard to keep a zero" and "impossible to zero" are two very different things. Hopefully he has the integrity to make things right.
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You admitted it's a red flag but bought anyways. Hope it works out for you, but hard to keep zero and not zeroing are essential both indicating it's broken. A zero shouldn't wander, either the bases are loose, rings are crappy or the scope is junk. The first two can usually be found when inspecting a rifle for purchase.
 
As per Dmay, I think its premature to conclude the scope is pooched. You may not appear to have adequate scope adjustment due to the fact that the optically centered scope and the bore are not parallel to begin with. ( suspect rings, receiver machining, etc.) Additionally, bore sighting is a very rough proxy for actually shooting the rifle.
Without shooting it, and on a known good rifle, its impossible to make a valid conclusion.
 
Perhaps the original owners wandering zero issue was due to a faulty scope installation.

Debris under the base, incorrect torque on the base screws or ring caps, low quality rungs, etc etc.
 
Sorry I missed this, but have you shot the rifle? I have a sig cross in 6.5 CM in a zero MOA 1.5" high Spuhr mount with a Minox ZP5 scope. I zeroed at 100 yards and I have 26 mils out of the available 28 mils available for adjustment. If you haven't done so take it to the range and try it out with some ammo just to be sure the scope is buggered.
 
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