Rifle Scopes 100 yard zero problem

Texas_Archer

Long-time Lurker
Full Member
Minuteman
Sep 18, 2009
100
0
Houston, TX
I own 5 Trijicon scopes and really like the quality I get with them. However, my latest purchase is giving me problems with my 100 yard zero. Apparently, I do not have enough elevation clicks to zero in at 100 yards, in fact, I need at least 12 clicks (3 inches) to hit the bullseye at 100 yards. I have no problems with the other guns with TR23-2G scopes mounted, so Im thinking it might be the scope. I wanted to stop by here and run it by you guys first. Here is the stats on the guns and a picture. The problem gun is the Savage 10 PC.

Savage - 16" barrel - Badger 20 MOA base - Badger Low Rings - Trijicon TR23-2G scope - ~1.75" from center of scope to center of bore.

FN PBR - 18" barrel - Badger 20 MOA base- Badger Low Rings - Trijicon TR22 scope - ~2" from center of scope to center of bore.

Larue OBR - 16" barrel - 20 MOA base - Larue Mount - Trijicon TR23-2G scope - ~3.25" from center of scope to center of bore.

Larue Stealth - 18" barrel - Larue Mount - Trijicon TR23-2G scope - ~2.75" center of scope to center of bore.

Any thoughts, help, or suggestions on why the Savage needs 3" to zero at 100 yards?

IMG_0007.jpg
 

TrooperBrian

Sergeant
Full Member
Minuteman
May 27, 2010
427
0
33
Idaho, USA
Re: 100 yard zero problem

Just depends on the rifle, nothing wrong with the scope I'd say. My Nightforce needed a 5+ turret turn to elevation zero on a Rem700 and 0MOA base.
 

LoneWolfUSMC

Lt. Colonel
Full Member
Minuteman
Jan 9, 2008
7,386
13
Southern Indiana
www.8541tactical.com
Re: 100 yard zero problem

Remove the scope from the rings. Clean the rings, make sure there is no lint, dirt, grit, etc.

Remount the scope and see if you get a change.

Now if I understand you right you are saying that you are topped out and still need 3 MOA to be zeroed.

If the scope is properly mounted and the base is properly mounted I would be swapping that scope onto another platform and see if the problem persists. If it does, ship it back. If it doesn't then new rings, base or some gunsmithing may be in order.
 

Texas_Archer

Long-time Lurker
Full Member
Minuteman
Sep 18, 2009
100
0
Houston, TX
Re: 100 yard zero problem

Im maxed out in the negative (down) elevation and still shooting 3" high at 100 yards. The scope ocular only has about .25" before touching the top of the barrel, in fact, the scope rings touch the barrel when on the scope. The mount is a Badger 20 MOA mount and was installed by GAP. The rings are Badger Standard (low) rings and were installed at 16 in/lbs.
 

MistWolf

Private
Full Member
Minuteman
May 29, 2010
44
0
60
Re: 100 yard zero problem

Center your windage adjustment. This will center the erector set inside the tube. After doing this, set your elevation without correcting for windage. If this works it's possible your mounts are not centered over your bore. If so, correcting for windage means the erector set will be too far to the left or the right and will hit the inside of the scope tube before reaching the elevation needed.

It also stands to reason that since your at the extreme end of the elevation travel, it will limit your windage adjustment in the same manner.

You will also note that the Savage has the shortest distance between the center of the scope and center of the bore. All else being equal, the scope being mounted close to the bore will raise your point of impact. If you raise the scope, it will lower the point of impact.

That 20 MOA mount isn't 100 yard friendly either
 

JamieD

Wolf Precision, Inc.
Full Member
Minuteman
Jul 17, 2007
925
75
Johnstown,pa
www.wolfprecision.net
Re: 100 yard zero problem

You could use a set of Buris Z-rings. They have nylon shims that you can install front and rear in the rings to help you zero. The thing I would do is change the base to a zero MOA. Doing so should still give you plenty of elevation. If you use a 10MOA base you might still have a problem and wast 100+ dollars.


The problem with some guns is the barrel/bore is not perfectly straight. They can be installed with the muzzle indexed pointed up, down,left or right giving you artificial windage or elevation. When installing a custom barrel, this is something you check for and index up giving you a little extra elevation. In some cases it gives a little too much.


JamieD
Wolf Precision
 

rezmedic54

Sergeant
Full Member
Minuteman
Jul 17, 2005
151
0
AZ
www.maricopashooting.com
Re: 100 yard zero problem

I've seen the problem many times before it's the base 20 is to much for the Savage. When I mount a scope to a Savage I shim the rear base (always use 2 piece bases) .20 higher then the rear this usually gives me all the up adjustment in tne scope. I also us the Millet angle-loc rings which give me the angle without binding the scope. I have found this more to be true for Savage then any other rifles. I have done this on 6 Savages and all have worked fine. What you have now is a 300 yd. zero rifle.
 

AQC440

Sergeant
Full Member
Minuteman
Jan 25, 2009
134
0
56
Bagdad, Kentucky
Re: 100 yard zero problem

I am not familiar with the optic or the rifle and should probably keep my mouth shut...but!

If your particular scope doesn't have enough adj. to make up for the 20 MOA base and it is a mil-dot scope, the first dot "up" should only impact about .5 inches high at a hundred when the scope is set to its mil reading power setting. This is based on you saying the POI is 3" high at 100 yds...
 

Texas_Archer

Long-time Lurker
Full Member
Minuteman
Sep 18, 2009
100
0
Houston, TX
Re: 100 yard zero problem

The thing that has me scratching my head is that even though there is a 20 MOA base, the rings are low and the scope clearance from the barrel is only 1/4". If I replaced the 20 MOA rail with a 0 MOA rail I would have to increase the ring height and would still be back to where I am now - Correct?
 

former naval person

Gunny Sergeant
Full Member
Minuteman
May 8, 2003
3,032
2
82
Mississippi
Re: 100 yard zero problem

I believe that the rear of a 20 MOA base is the highest...sort of like pistol iron sights...move the rear in the direction you want to have the shot go. By elevating the rear mount you are moving the impact of the shot higher, necessitating in your case using up all the negative elevation adjustment the scope has internally. By going to a straight base you lower the impact by 20 MOA which should give you a setting in the middle of the adjustment range of the scope...and as MistWolf says, you'll have more windage adjustment available. You'll increase, not decrease, the clearance between the scope bell and the barrel. JMHO
 

bignada

Sergeant
Full Member
Minuteman
Sep 30, 2009
308
0
37
Re: 100 yard zero problem

Think I would ditch the Badger base and try a set of cheap Weavers.
Both those bolt rifles barrels are so short, evidently you are not looking for 800+ yard performance.

Why the +20moa base in the first place on a 18 or 20" barreled rifle?

You are getting good info about scope being hindered by top most reticle positioning. If you know what the other scopes you own will do, swap the scope from that savage 10pc to a weapon that
has no issues.

You might consider buying a tool like a Bushnell 74-3333 bore sighter. That tool has a optic with grid to enable diagnosis of problem and confirmation of zero. Set your scope up with the boresighter, shoot/zero, and then record your reticle position on the grid when zeroed at range you intend to use. You can also do box-checks and ascertain reticle alignment along with other diagnostics when you have a problem. Worth every dime it costs.


 

MistWolf

Private
Full Member
Minuteman
May 29, 2010
44
0
60
Re: 100 yard zero problem

The 20 MOA mount is higher in the rear than the front, tilting the scope slightly downward in relationship to your bore, raising your point of impact letting yu get on target at extended ranges.

A 0 mount runs the scope parallel to the bore. This will lower your POI compared to the 20 MOA mount and let you get on target at 100 yards
 

Wild_Bill

Gunny Sergeant
Full Member
Minuteman
Oct 22, 2007
1,055
8
50
Victoria Australia
Re: 100 yard zero problem

ist question how much elevation is the scope supposed to have? if it is less than 40 moa it iwll not work with the 20 moa base. i would just set it up on a 0, 10 or even 15moa base and it will be fine. what distance do you want to shoot it to? if only to around 500 you will be fine with the 0 base if further you will have to try to get a base closer to being zero'd near full down on your turret. we have to play around with rails on target rifles when they are on a 223 shooting 1000 yards with a Nightforce benchrest as they only have 40moa so we machine the bases to suit. if you know someone with a mill that is competent they could machine the bottom of the base to remove 5 moa taper GAP could do i i emagine if they built the rifle for you this would be the way to get a 15moa base allowing you your 100 yard zero and having around 2 moa under your zero so the scope is not bottmed out and will allow you to have the most elevation travel available for use if done correctly the scope objective will actualy be a little further from the barrel aswell.

Otherwise get a custom base or go back to a flat base.
 

VKC

Gunny Sergeant
Full Member
Minuteman
Mar 29, 2010
2,328
5
Battle Born, U.S.A.
Re: 100 yard zero problem

Trijicon is a high-quality product and with 5-20x, you should have plenty of clicks to zero at 100 yards even with a 20MOA base.

A possibility is that there is something wrong with your scope. Another possibility is that it is a counterfeit, not implying anything, but there are a lot out there.

Depending on if you are hitting high or low, with a 20MOA sloped base, you can try moving you scope forward or back to adjust.

Another possibility is your flash suppressor is shifting your point of impact.

Also I would check to make sure the rings and base were installed correctly. If the rings are overtightened, they can distort the image.
 

Texas_Archer

Long-time Lurker
Full Member
Minuteman
Sep 18, 2009
100
0
Houston, TX
Re: 100 yard zero problem

Scope was purchased new from US Cavalry so I think it is authintic. I'm going to take the 2.5-10x56 off the FN and put it on the Savage next to see how that shoots. They are both in Badger low rings.
 

VKC

Gunny Sergeant
Full Member
Minuteman
Mar 29, 2010
2,328
5
Battle Born, U.S.A.
Re: 100 yard zero problem

With any many Trijicon scopes as you have, I guess you should know if they are real or not. Curious to see what happens when you remount FN scope onto the Savage. Let us know.