To shim or not to shim

[Blackhawk]

Here is my dilemma.
I just purchased a savage high country rifle in .300Win Mag.
I mounted a Weaver 20 MOA rail (checked for flatness and spring)
then using Weaver Gram Slam rings in the high configuration set a Nikon Monarch #5 5.0 x 20 X 50 with ED Glass.( rings were lapped as a unit before scope was mounted )
This combination allowed me just over 1/8" clearance between the bottom of the rifle scope bell and the top of the rifle barrel so I assumed that I was OK.
After load development started I realized that even though my Ed and SD numbers were promising I was 2" high @100yards I brought my scope's adjust down until it peaked out and still I was 2" high.
Now the question I ordered new Weaver Grand Slam Rings in a medium height and hopefully this may solve my issue but in the interim, I was wondering if shimming the scope would possibly help.
To that end, if my downward scope adjustment is maxed out and I am still 2" high at @100yards which ring do I need to shim the front or rear in order to make the necessary adjustments how much shim height will be needed.
My gut tells me it would take a .005" shim under the front ring in order to make the correct amount of adjustment.
On the other side of the coin @ 200 meters I am dead on so shall I shim this scope, put on lower rings,or leave it alone.
Your thoughts, please.

 

[sw282]

Burris 30mm Signature Zee Weaver-Style Rings Matte Black Medium

The revolutionary Signature design produces consistent accuracy, tremendous gripping power and stress-free mounting. These steel rings include a...

www.midwayusa.com

Burris Weaver style Z rings have plastic inserts that can be offset to give you extra elevation
if needed. Just read the instructions... Added bonus-No scope ring marks left on scope tube

 

[Blackhawk]

Burris 30mm Signature Zee Weaver-Style Rings Matte Black Medium

The revolutionary Signature design produces consistent accuracy, tremendous gripping power and stress-free mounting. These steel rings include a...

www.midwayusa.com

Burris Weaver style Z rings have plastic inserts that can be offset to give you extra elevation
if needed. Just read the instructions... Added bonus-No scope ring marks left on scope tube

I Know that the Burris rings themselves are made from steel but I'm concerned that they will not take the abuse of the continuous firing of the .300 Winchester Magnum round with out slippage, as the inserts themselves are made from a plastic derivative material which is very smooth and somewhat slick to the touch.
However in the long run they may be an easy solution to my dilemma.
Thank You for your timely response!

 

[MallardAddict]

The Burris inserts aren't that soft but do grip the scope texture just fine. I know lots of guys that love them and never heard of them slipping assuming they were torqued properly

 

[bassassassin104]

If I'm thinking correctly, 0 moa rail should fix the issue?

 

[just_jon]

Properly installed, 300WM recoil will not result in slippage.

 

[jdyoung]

What zero are you trying to achieve ?

 

[Far North Hunter]

The Burris rings should solve the issue. As stated prior torque down propenly, use there spec, and your good to go.

 

[skipglo]

Here is my dilemma.
I just purchased a savage high country rifle in .300Win Mag.
I mounted a Weaver 20 MOA rail (checked for flatness and spring)
then using Weaver Gram Slam rings in the high configuration set a Nikon Monarch #5 5.0 x 20 X 50 with ED Glass.( rings were lapped as a unit before scope was mounted )
This combination allowed me just over 1/8" clearance between the bottom of the rifle scope bell and the top of the rifle barrel so I assumed that I was OK.
After load development started I realized that even though my Ed and SD numbers were promising I was 2" high @100yards I brought my scope's adjust down until it peaked out and still I was 2" high.
Now the question I ordered new Weaver Grand Slam Rings in a medium height and hopefully this may solve my issue but in the interim, I was wondering if shimming the scope would possibly help.
To that end, if my downward scope adjustment is maxed out and I am still 2" high at @100yards which ring do I need to shim the front or rear in order to make the necessary adjustments how much shim height will be needed.
My gut tells me it would take a .005" shim under the front ring in order to make the correct amount of adjustment.
On the other side of the coin @ 200 meters I am dead on so shall I shim this scope, put on lower rings,or leave it alone.
Your thoughts, please.

Leave it alone! 200 is a great zero....point and pull to 300 yrds. Just me

 

[blackburbot]

If looking at the right scope on the website. It says you have 45moa of adjustment. So 22.5either way. If trying to run a 20moa base you will most likely run out of adjustment. Scope ring heigh really doesn't do anything except bring the scope closer to the barrel. Would look at getting a 10MOA rail or a zero MOA ... Some suggested the burris rings with plastic inserts. Have them set up so they are putting 10moa in the front of the scope to try leveling it out

 

[blackburbot]

Or just be super happy with a 200 yard zero, knowing that you have 45moa to work with for distance shooting. Should get close to 1700yards using turrets.

Just a matter of remembering that at close range you will be a little high. Still kill shot territory for deer/moose/elk

 

[Blackhawk]

If I'm thinking correctly, 0 moa rail should fix the issue?

If I'm thinking correctly, 0 moa rail should fix the issue?

What zero are you trying to achieve ?
I am working on load development and because of the shortage of Alliant RL - 22 powder which allowed a 180 Grain SST Hornady ( I am working up a hunting load using Alliant RL- 22 powder) can print on paper less than 1/2" MOA @ 100 yards and my scope will track dead on. (Nikon Monarch 5 4 x20 x50 ED).

When I had go use Hodgdon H-4350 simply because Alliant RL -22 is unavailable and according to my dealer who is a very close friend will be unavailable from Sweden for 1 -1 1/2 years my scopes elevation is bottomed out and to my surprise still held to 1/2" MOA groups however my POI is now 2.000" high@ 100yards.

In answer to your question during this stage of load development I am working with a target zero of 100 yards.
In fairness my scope is mounted on a 20 mm rail which I do not want to change.
Note: at 200 meters I am spot on I've never encountered such a shift in POI POA @100 yards before and I was thinking of shimming my front ring in order to add the additional amount of height that I need in order to achieve a 100 yard zero.
The Burris Z rings may be a viable alternative allowing me to adjust now for the Hodgdon H -4350 powder and when Alliant RL-22 becomes available easily switch back and re zero back.
This is simply for load development . do you think that I should just compensate for the 2.000" hold over @ 100yards or make adjustments by a changeout of rings.

Setup:
Rifle is a Savage High Country
Chambered for .300 Winchester magnum
Scope Nikon Monarch 5 Ed glass 4 X 20 X 50mm
A 20 Moa Weaver rail using Weaver High Grand Slam Steel Rings
Your thoughts and recommendations on this as I certainly do not like to have my scopes elevation adjustment bottomed out.

 

[Varmint Hunter]

1. You can't lower the scope because the bell will hit the barrel and it is already too close IMO. Scope tubes bend and flex under recoil. You also want enough room for a scope cap of some sort. Its a pain when they don't fit because the bell is almost touching the barrel.

2. Lowering the scope won't help anyway, changing the mount angle will.

3. Leaving the reticle in the extreme so that you can just get on target at 200yds is a bad idea. The reticle should be near the center of its adjustment. That's why 1,000 yd shooters started using the 20moa bases in the first place.

4. A 10moa base (of the same height or higher) would solve the problem but would not get you to extreme ranges if that's important.

5. Burris Signature rings would definitely solve the problem. They have many different size inserts and you could custom tailor the angle to your liking and change it at will. Inserts can be used to raise and/or lower either end of the scope with NO CHANCE of binding the scope tube if installed properly. Note - they should always be installed with mated halves. If you need instructions look on youtube. Scopes slipping in the inserts should not be an issue. I have them on rifles in 300RUM and 338RUM, both of which are shooting maximum loads without issue.

6. Shimming rings is an inherently bad idea and I wouldn't shim the base either.

Just my 2 cents. I hope it helps.

 

[shortgrass]

Here is my dilemma.
After load development started I realized that even though my Ed and SD numbers were promising I was 2" high @100yards I brought my scope's adjust down until it peaked out and still I was 2" high.
On the other side of the coin @ 200 meters I am dead on so shall I shim this scope, put on lower rings,or leave it alone.
Your thoughts, please.

Are you certain the scope is OK. If you were still 2" high after adjusting the elevation in the scope, and you started out 2" high before adjusting, something must be wrong with the scope. The elevation never moved!