Shimming scope mount: Opinions needed!

tkofoid · January 25, 2010, 11:13 PM

Ruger integral mounts: I bedded the lower mount ring to get a good fit. But, when mountng the scope I must shim the rear of the scope to get enuf elevation for long yardage. What type of material shall I use to line my rear mount to accomplish this? If this were a traditional mounting system, (bases and rings) I would simply shim the rear base, but in the case of ruger rings it is not possible. Any suggestions would be appreciated. Anyone with the exact scenario? Thanks

Malamute · January 25, 2010, 11:18 PM

Are you sure you have run out of adjustment in the scope for the range you are shooting?

I'm not sure it's a good idea to shim the scope in the rings. Someone else may know more about it, but I think I'd want a better ring/scope fit than a shimmed fit would give.

tkofoid · January 25, 2010, 11:24 PM

Malamute: Yes, I do believe, based on prior experience, that I will not get the adjustment I need for 600 yards. I have needed to shim in the past,but as I mentioned these rings cannot be shimmed at the base. Thanks for your response.

Huffmanite · January 26, 2010, 12:53 AM

I have used metal cut from either an aluminum beer or soft drink can as a shim. Also, epoxy putty may work. Kneed a piece, flatten it out, lay in ring and then tighten down ring to where you want it. Trim off excess. Of course, apply a release agent to your scope first.

James K · January 26, 2010, 11:43 PM

Don't use epoxy, you won't be able to get it off. The scope will hold a shim in place, and it will be easy to get out if you want to remove it or replace it with a thicker shim.

Jim

croc4 · January 27, 2010, 12:04 AM

I can't recommend them enough, I have been down the "shimming" road before, and it never left me with a warm fuzzy. After moving to these I have never looked back.

Croc4

highvel · January 27, 2010, 08:12 AM

I have had to shim bases before, but never the rings.
If I had to I would buy a set of feeler gages that come in sizes .001" thru around .035".
They are about 1/2" wide and around three inches in length, you can cut them to length, that way you can get the exact amount of shim you need.

I believe shimming rings may torque or induce a bend to the scope tube and may cause trouble holding zero properly though.

Good luck

Idahogunsmith · January 27, 2010, 03:11 PM

Shim stock can be bought in host of thickness to resolve you issue from usually a bearing supply store. The next best solution was the one already given, you can buy brass ignition feeler gauges at a local auto parts store. Usually folks shim to get the scope and the lense paralex perfect aligned before using the elevation knobs but it should work Good Luck Mac

dmazur · January 27, 2010, 03:24 PM

I ran into a related problem when I had to correct for an "off-level" Ruger quarter rib on a #1. The front of the rib was higher than the back...this is similar to needing to raise the rear ring for long range work.

As the Burris Z-rings aren't available for Ruger mounts, you can either get a Ruger to Weaver adapter so you can use Burris rings (kind of klugy looking), or you can lap the front ring lower.

Believe me, this is a lot of work! If you are trying for 0.012" or so, it takes an awful lot of lapping compound and an entire day to do this right.

When you're done, the rings are parallel and the front ring is lower than it was when it started. The front edge of the rear ring is also slightly lower.

If you take the ring down far enough, say 0.030", you may have to flat file the "ears" of the lower ring half a little so the upper ring half will still clamp.

tkofoid · January 27, 2010, 05:47 PM

Thanks for all the responses! As I mentioned, I have already bedded the lower rings. I am going to rip that out and start over using the the top ring to place the scope up or down as far as I wish. At the end of the day, I should end up with perfectly fitting mounts, without lapping, and the elevation in the rear exactly high enough so I can get to the desired objective. I have bedded other scopes with JB weld with great success,but never for a 600 yard gun. I have a long winter ahead here in N.D. so I have plenty of time to do it. Feel free to shoot holes in my plan.

CarterMccoy · January 27, 2010, 05:57 PM

My daddy told me once "A shim is a fool's own downfall".
Get the mount right and never touch it again.
IMHO.

I have NEVER had ANY luck shimming anything, and never met anyone who has.

RoyP · January 27, 2010, 09:03 PM

I have shimmed between the scope and ring before without any problems. I use a piece of milk jug or other plastic material. That way you don't scratch up the scope.

Malamute · January 27, 2010, 09:06 PM

"...Get the mount right....."

Not much you can do with Ruger "mounts".

I don't quite understand what you're planning with the "top ring". Have you actually sighted this scope in on this gun with the loads you're going to use? If zero'ed @ 100 yards, you can do the math and find out how much adjustment you need to zero for 600, and see if it adjusts that far. Before doing anything heroic, I'd see if it really needs to be done first.

If you do anything to change the height of the base/scope relationship, you are going to change the alignment of the rings. Torqueing the scope unevenly in the rings can damage the scope and cause problems with it's function. That's what the lapping is about when changing anything, to asssure both rings bores are perfectly parallel.

Some scopes also have more adjustment range than others.

http://demigodllc.com/articles/pract...ing-equipment/

thallub · January 27, 2010, 10:15 PM

Shimming rings and mounts is not the way to go. Night-Force tapered MOA bases will take care of the problem. Yep, they do get pricey but they are worth it.

OOps read the part where it has integral mounts. These will not work.

http://nightforceoptics.com/nightfor...___mounts.html

Malamute · January 28, 2010, 10:38 AM

Something just occured to me when reading the last post. Some of the early Ruger 77's were made as "round tops" without the integral Ruger ring bases. The round tops used Remington 700 scope bases. If one really needed the extra adjustment for lonager range, you could contour the reciever top, drill and tap for Remington type bases, and use those +20 or +30 MOA bases.

I'd still try the scope in question to see if it has the adjustment range for the load you will use. 600 isnt all that far. 1000 is.

Another scope may be a simpler option also.

ackley man · January 29, 2010, 02:32 PM

Attemting to shim between the scope tube and ring will unquestionably lead you down the road to disaster! Even the slighest uneven pressure on the scope tube will effect the erector lens inside of the scope and screw up the accuracy of your scope windage and/or elevation adjustments. This is why proper mounting of a scope requires alignment of the rings with an alignment tool and laping of the rings with a laping tool and compound. The proper solution to your problem is relatively simple - Burris make rings called Signature rings. Each ring has an articulating (2 piece) insert that rotates inside of the ring to self align the scope. For these rings they sell a kit called Pos-Align Offset Inserts. With the offset inserts you can gain the elevation that you require. You should note that you cannot mix and match the pieces from the insert kit. In other words if you use a +20 insert bottom you must use the +20 top. Using the Signature rings and offset inserts you will accomplish your goal without causing damage to your scope tube and internal workings of your scope. Finally, this is a much more cost effective than purchasing a tactical scope mount. Good luck.
Doug @ Firearms Unlimited

tkofoid · January 30, 2010, 10:22 AM

I have bedded more than one scope in the lower ring with great success.
It is the same and exact theory as bedding the rifle to its stock. The purpose for bedding the rifle to its stock is to create a stress - free , yet secure, enviroment. The same scenaria applys to the scope. By lapping the rings, one takes out enough material for the scope to lay in a true, non binding platform. Filling any voids with epoxy in the rings creates that ''true and non-binding'' platform. I use the top ring to simply hold the scope in place. It takes very little tention to do this once the lower rings are trued up. I place rosin in the lower ring unto the epoxy to create a non slip surface for the scope to rest in. In this case I am simply going to elevate the rear of the scope via placing enough epoxy in the ring to do raise the rear of the scope .010". I have a couple rifles with the burris signature rings and love-em. In this case I am going to use the intregal rings designed for the rifle.

Harry Bonar · January 30, 2010, 04:24 PM

Sir;
Leupold shims either the rear base or the rear ring to get more vertical adjustment - this is common with high magnification scopes.
Harry B.

clevacat · January 30, 2010, 06:52 PM

Are you using this rifle for range or field shooting? If you are range shooting I can see you may have a problem depending on the scope. If you are field shooting why do you want a 600 yard yero?? I've shot literaly hundreds of camels and donkeys here in Western Australia with my Ruger M77 300WM , we zero at 300 meters and anything out further just hold over.I agree with previous comments, try the scope first and see how much elevation you can actually get out of it

KEN K · January 30, 2010, 09:33 PM

Try aluminum, just fold it over it's self to the thickness you want if it's to thick take a fold or two off.

tkofoid · January 31, 2010, 10:38 AM

Clevacat: This is for my ''fun gun''. It will be used almost exclusively for 300 & 600 yard target shooting. On my hunting rigs I do as you do: zero at 300 yds and compensate for anything farther out. Last evening I bedded my rings as described earlier with a .010" lift on the rear ring via laying a small piece of .010" feeler gauge in the bottom. It turned out beautifully,, smooth as a baby's butt; and very true. I now have no question the scope will have enough elevation to get to where I wanna go. Thanks to all for your responses and concerns.

January 25, 2010, 11:18 PM	#2
Malamute Senior Member Join Date: June 6, 2004 Location: Rocky Mts Posts: 859	Are you sure you have run out of adjustment in the scope for the range you are shooting? I'm not sure it's a good idea to shim the scope in the rings. Someone else may know more about it, but I think I'd want a better ring/scope fit than a shimmed fit would give. __________________ "Far better it is to dare mighty things, to win glorious triumphs even though checkered by failure, than to rank with those poor spirits who neither enjoy nor suffer much because they live in the gray twilight that knows neither victory nor defeat." -Theodore Roosevelt-

January 27, 2010, 12:04 AM	#6
croc4 Senior Member Join Date: March 9, 2006 Location: Idaho Posts: 191	Burris Zee signature rings I can't recommend them enough, I have been down the "shimming" road before, and it never left me with a warm fuzzy. After moving to these I have never looked back. Croc4

January 27, 2010, 08:12 AM	#7
highvel Senior Member Join Date: January 21, 2010 Location: Powhatan VA Posts: 633	I have had to shim bases before, but never the rings. If I had to I would buy a set of feeler gages that come in sizes .001" thru around .035". They are about 1/2" wide and around three inches in length, you can cut them to length, that way you can get the exact amount of shim you need. I believe shimming rings may torque or induce a bend to the scope tube and may cause trouble holding zero properly though. Good luck Last edited by highvel; January 27, 2010 at 08:20 AM. Reason: Forgot something

January 27, 2010, 03:11 PM	#8
Idahogunsmith Junior Member Join Date: January 27, 2010 Location: Boise Idaho Posts: 9	Ouch Shim stock can be bought in host of thickness to resolve you issue from usually a bearing supply store. The next best solution was the one already given, you can buy brass ignition feeler gauges at a local auto parts store. Usually folks shim to get the scope and the lense paralex perfect aligned before using the elevation knobs but it should work Good Luck Mac

January 27, 2010, 03:24 PM	#9
dmazur Senior Member Join Date: July 5, 2007 Location: Pacific NW Posts: 1,310	I ran into a related problem when I had to correct for an "off-level" Ruger quarter rib on a #1. The front of the rib was higher than the back...this is similar to needing to raise the rear ring for long range work. As the Burris Z-rings aren't available for Ruger mounts, you can either get a Ruger to Weaver adapter so you can use Burris rings (kind of klugy looking), or you can lap the front ring lower. Believe me, this is a lot of work! If you are trying for 0.012" or so, it takes an awful lot of lapping compound and an entire day to do this right. When you're done, the rings are parallel and the front ring is lower than it was when it started. The front edge of the rear ring is also slightly lower. If you take the ring down far enough, say 0.030", you may have to flat file the "ears" of the lower ring half a little so the upper ring half will still clamp. __________________ .30-06 Springfield: 100 yrs + and still going strong

January 25, 2010, 11:13 PM	#1
tkofoid Senior Member Join Date: October 10, 2008 Location: N. D. Posts: 149	Shimming scope mount: Opinions needed! Ruger integral mounts: I bedded the lower mount ring to get a good fit. But, when mountng the scope I must shim the rear of the scope to get enuf elevation for long yardage. What type of material shall I use to line my rear mount to accomplish this? If this were a traditional mounting system, (bases and rings) I would simply shim the rear base, but in the case of ruger rings it is not possible. Any suggestions would be appreciated. Anyone with the exact scenario? Thanks

January 25, 2010, 11:24 PM	#3
tkofoid Senior Member Join Date: October 10, 2008 Location: N. D. Posts: 149	Malamute: Yes, I do believe, based on prior experience, that I will not get the adjustment I need for 600 yards. I have needed to shim in the past,but as I mentioned these rings cannot be shimmed at the base. Thanks for your response.

January 26, 2010, 12:53 AM	#4
Huffmanite Senior Member Join Date: February 17, 2006 Location: Northeast of Houston, Tx Posts: 393	I have used metal cut from either an aluminum beer or soft drink can as a shim. Also, epoxy putty may work. Kneed a piece, flatten it out, lay in ring and then tighten down ring to where you want it. Trim off excess. Of course, apply a release agent to your scope first.

January 26, 2010, 11:43 PM	#5
James K Member In Memoriam Join Date: March 17, 1999 Posts: 24,383	Don't use epoxy, you won't be able to get it off. The scope will hold a shim in place, and it will be easy to get out if you want to remove it or replace it with a thicker shim. Jim

January 27, 2010, 05:47 PM	#10
tkofoid Senior Member Join Date: October 10, 2008 Location: N. D. Posts: 149	My Plan is in play Thanks for all the responses! As I mentioned, I have already bedded the lower rings. I am going to rip that out and start over using the the top ring to place the scope up or down as far as I wish. At the end of the day, I should end up with perfectly fitting mounts, without lapping, and the elevation in the rear exactly high enough so I can get to the desired objective. I have bedded other scopes with JB weld with great success,but never for a 600 yard gun. I have a long winter ahead here in N.D. so I have plenty of time to do it. Feel free to shoot holes in my plan.

January 27, 2010, 05:57 PM	#11
CarterMccoy Member Join Date: December 31, 2009 Posts: 66	NEVER SHIM My daddy told me once "A shim is a fool's own downfall". Get the mount right and never touch it again. IMHO. I have NEVER had ANY luck shimming anything, and never met anyone who has.

January 27, 2010, 09:03 PM	#12
RoyP Senior Member Join Date: July 28, 2002 Location: corning,new york Posts: 217	I have shimmed between the scope and ring before without any problems. I use a piece of milk jug or other plastic material. That way you don't scratch up the scope.

January 27, 2010, 09:06 PM	#13
Malamute Senior Member Join Date: June 6, 2004 Location: Rocky Mts Posts: 859	"...Get the mount right....." Not much you can do with Ruger "mounts". I don't quite understand what you're planning with the "top ring". Have you actually sighted this scope in on this gun with the loads you're going to use? If zero'ed @ 100 yards, you can do the math and find out how much adjustment you need to zero for 600, and see if it adjusts that far. Before doing anything heroic, I'd see if it really needs to be done first. If you do anything to change the height of the base/scope relationship, you are going to change the alignment of the rings. Torqueing the scope unevenly in the rings can damage the scope and cause problems with it's function. That's what the lapping is about when changing anything, to asssure both rings bores are perfectly parallel. Some scopes also have more adjustment range than others. http://demigodllc.com/articles/pract...ing-equipment/ __________________ "Far better it is to dare mighty things, to win glorious triumphs even though checkered by failure, than to rank with those poor spirits who neither enjoy nor suffer much because they live in the gray twilight that knows neither victory nor defeat." -Theodore Roosevelt- Last edited by Malamute; January 27, 2010 at 09:15 PM.

January 27, 2010, 10:15 PM	#14
thallub Senior Member Join Date: November 20, 2007 Location: South Western OK Posts: 3,112	Shimming rings and mounts is not the way to go. Night-Force tapered MOA bases will take care of the problem. Yep, they do get pricey but they are worth it. OOps read the part where it has integral mounts. These will not work. http://nightforceoptics.com/nightfor...___mounts.html Last edited by thallub; January 28, 2010 at 06:06 AM.

January 28, 2010, 10:38 AM	#15
Malamute Senior Member Join Date: June 6, 2004 Location: Rocky Mts Posts: 859	Something just occured to me when reading the last post. Some of the early Ruger 77's were made as "round tops" without the integral Ruger ring bases. The round tops used Remington 700 scope bases. If one really needed the extra adjustment for lonager range, you could contour the reciever top, drill and tap for Remington type bases, and use those +20 or +30 MOA bases. I'd still try the scope in question to see if it has the adjustment range for the load you will use. 600 isnt all that far. 1000 is. Another scope may be a simpler option also. __________________ "Far better it is to dare mighty things, to win glorious triumphs even though checkered by failure, than to rank with those poor spirits who neither enjoy nor suffer much because they live in the gray twilight that knows neither victory nor defeat." -Theodore Roosevelt-

January 29, 2010, 02:32 PM	#16
ackley man Junior Member Join Date: January 29, 2010 Location: Arizona Posts: 8	DON'T DO IT! Attemting to shim between the scope tube and ring will unquestionably lead you down the road to disaster! Even the slighest uneven pressure on the scope tube will effect the erector lens inside of the scope and screw up the accuracy of your scope windage and/or elevation adjustments. This is why proper mounting of a scope requires alignment of the rings with an alignment tool and laping of the rings with a laping tool and compound. The proper solution to your problem is relatively simple - Burris make rings called Signature rings. Each ring has an articulating (2 piece) insert that rotates inside of the ring to self align the scope. For these rings they sell a kit called Pos-Align Offset Inserts. With the offset inserts you can gain the elevation that you require. You should note that you cannot mix and match the pieces from the insert kit. In other words if you use a +20 insert bottom you must use the +20 top. Using the Signature rings and offset inserts you will accomplish your goal without causing damage to your scope tube and internal workings of your scope. Finally, this is a much more cost effective than purchasing a tactical scope mount. Good luck. Doug @ Firearms Unlimited

January 30, 2010, 10:22 AM	#17
tkofoid Senior Member Join Date: October 10, 2008 Location: N. D. Posts: 149	respectfully dissagree I have bedded more than one scope in the lower ring with great success. It is the same and exact theory as bedding the rifle to its stock. The purpose for bedding the rifle to its stock is to create a stress - free , yet secure, enviroment. The same scenaria applys to the scope. By lapping the rings, one takes out enough material for the scope to lay in a true, non binding platform. Filling any voids with epoxy in the rings creates that ''true and non-binding'' platform. I use the top ring to simply hold the scope in place. It takes very little tention to do this once the lower rings are trued up. I place rosin in the lower ring unto the epoxy to create a non slip surface for the scope to rest in. In this case I am simply going to elevate the rear of the scope via placing enough epoxy in the ring to do raise the rear of the scope .010". I have a couple rifles with the burris signature rings and love-em. In this case I am going to use the intregal rings designed for the rifle.

January 30, 2010, 04:24 PM	#18
Harry Bonar Senior Member Join Date: December 5, 2004 Location: In the Vincent, Ohio general area. Posts: 1,804	shim Sir; Leupold shims either the rear base or the rear ring to get more vertical adjustment - this is common with high magnification scopes. Harry B.

January 30, 2010, 06:52 PM	#19
clevacat Junior Member Join Date: January 30, 2010 Posts: 4	Are you using this rifle for range or field shooting? If you are range shooting I can see you may have a problem depending on the scope. If you are field shooting why do you want a 600 yard yero?? I've shot literaly hundreds of camels and donkeys here in Western Australia with my Ruger M77 300WM , we zero at 300 meters and anything out further just hold over.I agree with previous comments, try the scope first and see how much elevation you can actually get out of it

January 30, 2010, 09:33 PM	#20
KEN K Senior Member Join Date: October 7, 2006 Location: mid west Georgia Posts: 102	Try aluminum, just fold it over it's self to the thickness you want if it's to thick take a fold or two off.

January 31, 2010, 10:38 AM	#21
tkofoid Senior Member Join Date: October 10, 2008 Location: N. D. Posts: 149	done deal! Clevacat: This is for my ''fun gun''. It will be used almost exclusively for 300 & 600 yard target shooting. On my hunting rigs I do as you do: zero at 300 yds and compensate for anything farther out. Last evening I bedded my rings as described earlier with a .010" lift on the rear ring via laying a small piece of .010" feeler gauge in the bottom. It turned out beautifully,, smooth as a baby's butt; and very true. I now have no question the scope will have enough elevation to get to where I wanna go. Thanks to all for your responses and concerns.