Visit the SWFA.com site to check out our current specials. |
Need help with scope moving. |
Post Reply |
Author | |
Bigdave
Optics Apprentice Joined: September/21/2009 Location: Houston Texas Status: Offline Points: 238 |
Post Options
Thanks(0)
Posted: November/29/2009 at 01:20 |
I probably sound foolish here, but I am having problems with my rifle scope spining in the rings on my rifle. It's a .300wsm 700 sps varmit, and I have a Nikon Buckmaster 6-18x40 scope on it. I am using Burris signature dual dovetail rings and base the scope wieghs in just under 20oz. I switched to this ring and base combo due to the scope sliding all over the place with a weaver style set up, I seem to have eliminated the forward back sliding of the scope. But now after about 100 rounds going through it the scope has spun about 20 degrees to the right, I know the screws on the rings haven't losened because I used red lock tight and a torque wrench to torque them down to 70 in. lbs. Does anyone have any Ideas on any changes I could make, or is the scope just flat out to heavy? Crazy thing is, the scope is rotating and not loosing it's zero at all.
|
|
biggreen747
Optics Journeyman Joined: October/16/2009 Location: Colorado Status: Offline Points: 470 |
Post Options
Thanks(0)
|
Which inserts do you have in your signature rings???
|
|
We measure it with a micrometer, mark it with a crayon, and cut it with a chainsaw.
|
|
biggreen747
Optics Journeyman Joined: October/16/2009 Location: Colorado Status: Offline Points: 470 |
Post Options
Thanks(0)
|
In all honesty if your scope was sliding back and forth in another set of rings and now turning in Signatures it sounds as though your scope tube may be smaller than spec... A 20oz scope should not be a problem in any rings and especially in the signatures.
|
|
We measure it with a micrometer, mark it with a crayon, and cut it with a chainsaw.
|
|
Bigdave
Optics Apprentice Joined: September/21/2009 Location: Houston Texas Status: Offline Points: 238 |
Post Options
Thanks(0)
|
I'm sorry, they are just double dove tail, not the ones that use inserts. Acording to my calipers the tube is a strait 1" even all the way down, should it be slightley larger? Reguardless, if it were off speck the rings would go all the way down on both sides and touch instead of not quite touching wouldn't they?
|
|
sakomato
Optics Master Joined: February/28/2008 Location: Houston Status: Offline Points: 1166 |
Post Options
Thanks(0)
|
I have heard of using a thin layer of liquid electricians tape or black silicone adhesive. IMO the rings should not touch when tight. You should never have to use loctite on any of your screws, especially the ring screws. Ring screws should only have to be torqued down to 20 inch pounds and bases to 60 pounds or lighter.
|
|
Guns only have 2 enemies, rust and politicians
|
|
Al Nyhus
Optics Apprentice Joined: March/08/2009 Status: Offline Points: 127 |
Post Options
Thanks(0)
|
Bigdave: Sounds like you need to have more surface contact between the i.d. of the rings and the o.d. of the scope tube.
The best way to get this is to bed the scope to the rings, using convention bedding compounds like AcraGlas Gel, etc. Don't use JB or any of the other 'hard' or metal filled epoxies for the job. Rough up the bottom ring halves, wipe 'em down with acetone, then apply a release agent to the scope tube and all other ring pieces. Lay the scope in the ring bottoms and lightly snug down the tops. After the compound dries, clean up all the excess and then repeat the process on the ring tops.
When you're finished, you'll have 100% contact between the tube and rings. A light snugging of the ring screws will be all that's needed to keep the scope in place. Bedded rings eliminate ring marks, pinched scope tubes and allow for a stress free scope....which helps the scopes mechanical performance. Once done, you can plop any scope you like on a setup like this and be assured of maximum contact....another nice feature.
If you don't want to go this way, the Burris insert-type rings have enough flex in the inserts to conform to the tube better and will generally stop the problem.
If you bed the bases first, then the rings, you'll have a bullet proof setup.
Good shootin'. -Al
|
|
"Marsupials scare me".
|
|
RONK
Optics Master Extraordinaire Joined: April/05/2007 Location: United States Status: Offline Points: 3199 |
Post Options
Thanks(0)
|
Al Nyhus' suggestion is probably the best, but I don't think you'd have to go that far if you don't wish to go to quite that much trouble, especially on a varmint rifle. (For a big-game rifle that you need to rely on for a once-in-a-lifetime hunt-go for it by all means!)
I think you possibly got a bit of oil or grease on the contact surfaces when you first assembled it, or maybe they are just too smooth.
Personally, I would lap the rings, but I don't think even that is really necessary in your case. Just disassemble everything, scuff the inside ring surfaces with 150 or 180 grit aluminum oxide or silicon carbide abrasive cloth or paper, trying to leave scratch patterns in several directions to prevent sliding and rotating. Clean all mating surfaces thoroughly with acetone or MEK and reassemble and torque to specs. Be sure that you haven't already stripped or stretched any of the screws by torqung them to 70 in.lbs. That is a lot, and might have ruined them or the tapped holes they fit into.
|
|
Sandracer
Optics Apprentice Joined: January/11/2009 Location: Eastern Oregon Status: Offline Points: 141 |
Post Options
Thanks(0)
|
What I found on one rifle/scope combo was the front and rear mount were not on the same plane. It took .040 " shim at the rear base to level the combo out. I use a solid shaft to align the mounts to each other although I have tried the two shafts turned down to a point on each end too! By the way the mounts that were way off were the Burris windage type and when I put on a new Leupold setup they were perfect! The guy that had this setup never could keep his scope from slipping either.
|
|
Al Nyhus
Optics Apprentice Joined: March/08/2009 Status: Offline Points: 127 |
Post Options
Thanks(0)
|
Excellent example, Sandracer. -Al
|
|
"Marsupials scare me".
|
|
Bigdave
Optics Apprentice Joined: September/21/2009 Location: Houston Texas Status: Offline Points: 238 |
Post Options
Thanks(0)
|
Thanks for the info guys, the glass bedding is probably the way to go, I am wanting to upgrade the scope anyhow. The 6-18 is more scope than I need and I would like to upgrade the quality of the glass, to something that I will not want to take off. My rifles have become a hobby to me, so I feel that taking the time to do it right is well worth it.
|
|
RONK
Optics Master Extraordinaire Joined: April/05/2007 Location: United States Status: Offline Points: 3199 |
Post Options
Thanks(0)
|
Yeah, you should probably use alignment bars to check out the trueness of your ring alignment, and if it's way off you might want to shim and lap and glass bed it!
A lot of work, but the results would be rock solid if you do it all properly. Good luck! |
|
Post Reply | |
Tweet
|
Forum Jump | Forum Permissions You cannot post new topics in this forum You cannot reply to topics in this forum You cannot delete your posts in this forum You cannot edit your posts in this forum You cannot create polls in this forum You cannot vote in polls in this forum |