Zeiss Conquest 6.5 x 20 x 50 on Remington 700

[mauihunter1980]

Help Please.
I just mounted a Zeiss Conquest 6.6-20 x 50 on a Remington 700 SPS .308
I'm using Medium Leupol Rings and Leupol 1 piece base. After leveling the rifle and the scope, I bore sighted it. Got to the range and had to raise the elevation by 16 MOA. Yes, a total of 64 clicks. It seems to me that I need a "Low" Ring for the rear mount. I don't think that's right.
Please any advise.gun)lightbulb

 

[Trever]

How did you bore sight it?

 

[winmagman]

Don't use 2 different height rings, this will stress the scope body and possibly cause other problems. If you don't feel you have enough "up" adjustment look into a set of Burris Signature Zee rings with the plastic inserts.. They allow for raising or lowering either end of the scope without any stress on the scope body.

Chris

 

[mauihunter1980]

How did you bore sight it?

Thanks for the reply.
I use a Tasco #30 and #35E bore sighter.

 

[kcebcj]

I have learned ring height has little to do with how much you have to dial up or down from the scopes reticle dead center. There are many paths but this is how I mount a scope and verify there are no mechanical problems before the site in.

Before installing the scope you should dial it all the way up and then all the way down and determine where the scopes center is. Both elevation and windage. Then with the rifle in a solid mount remove the bolt and level it across its rails. This should be done on a table or such with a wall about 20 feet away. Have a plumb bob hanging down the wall and align the bore center of the rifle with that string. Behind the string you need to get a mark on the wall center of the rifles bore which is zero elevation. I have a tape measure blade tacked to the wall I use right behind the plumb bob string and that makes it fast and easy. You could use a bore sighter here but I prefer to look through the bore

OK with the rifle all set up level and the bore lined up with the plum string and the mark on the center of the bore take the scope which is dialed to its center and just set it in the ring bases. Figure out the distance from the center of the rifles bore to the center of the scope somewhere between 1.5 and 2 inches depending on the rings Take that number and from the zero elevation mark on the wall measure up and put another mark. That should be the center of the reticle give or take a little.

Making sure the rifle does not move look through the scope. The reticle should align very closely to the plumb string for windage and the upper mark for elevation when it is centered. If there is a huge error there may be a mechanical problem with the receiver not being drilled properly or the base may have a problem. If the rear base has a windage screw make sure it was centered before you started. Use it to align the reticle with the plumb string as close as you can when doing the final adjustments to keep the vertical cross hair as close to center as possible in the scope. Generally the horizontal cross hair is quite close to the upper mark within a 1/2 inch or so. If the base has built in MOA understand that when evaluating the upper mark and the horizontal cross hair.

Taking a few minutes to do this will inform you as to whether there is a mechanical problem with the receiver the base or the scope and lay out a path to correct errors. If everything goes well align the vertical cross hair with the plumb string set the eye relief to fit and torque it down. I can usually go right to a paper at 100 yards from there depending....good luck

 

[bruce_ventura]

Thanks for the reply. I use a Tasco #30 and #35E bore sighter.

I can think of only four reasons for the zero to be off 12 MOA from boresight.

1. Bullet drop - accounts for about 3 MOA of the 12 MOA at 100 yds.

2. Barrel vibration. It's possible, but not common to see vibration throw shots away from boresight by more than 8-10 MOA. I've seen >10 MOA on big magnums like 300 H&H, but not on a .308.

3. Boresight collimator calibration is off. Again, possible but not likely that calibration is off more than 6 MOA.

4 Operator error using the collimator / poor spud fit in the bore. Late model Tasco spuds are undersized. This could account for up to 4-6 MOA of offset.

Seems like a combination of factors are at play here.

 

[mauihunter1980]

Jim,
I used to watch my dad go thru the steps you just mentioned. Bore sighting sometimes leads us to take short cuts. I will go "old school" and work from there.
Thank you for your input.
Paul

 

[mauihunter1980]

There is a good chance that Tasco Bore Sighter not accurate. As far a windage I'm ok. Very unlikely barrel vibration a factor, the .308 has a Bull Barrel. First shots was taken at 50 yds.
I will start from scratch and go over the steps paying attention to details.
Thank you for your reply!!

 

[bruce_ventura]

Try boresighting first by looking down the barrel with the bolt removed. Then compare that to boresighting using the Tasco collimator.

Tasco collimators are usually good quality. If the small cap on the end unscrews off, someone may have tried to "fix" it at some point and messed up the calibration. If the cap doesn't come off, the calibration is probably still accurate (<4 MOA error).