Scope rotates and shifts under recoil


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Zerstoerer
September 14, 2007, 11:42 PM
Other than brain surgeon advice such as 'tighten the screws' what else can be done?

Shot my .375 H&H Mgn for the first time-after the first shot I noticed the scope had rotated clockwise slightly. It also shifted back within the mounting rings by about 1/8".

Tried to tighten the screw for the forward rings (Cabela's Steel Standard) but the supplied Allen wrench was getting to 'rounded' already. All other 7 screws were tight all the way.

After that I shot another 10 rounds, mainly to fireform some brass and shot about a two inch group with it, telling me that it does not move much after the initial.

Any tricks - how about some black electrical tape on the inside of the rings?

Thanks

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R.W.Dale
September 14, 2007, 11:47 PM
In desperate situations I've placed a small daub of valve grinding compound inside each ring half. The very fine grit really locks things into place when the ring it torqued down.

But in your case I would buy some better quality rings.
Below is a picture of what a hard recoiling rifle can do to a set of chaep-o rings, the scope was also riuned

http://i3.photobucket.com/albums/y96/krochus/HPIM1690.jpg


http://i3.photobucket.com/albums/y96/krochus/HPIM1691.jpg

MCgunner
September 14, 2007, 11:48 PM
Millett;)

qbpc
September 14, 2007, 11:49 PM
Have your rings aligned honed or reamed for full scope contact. Take it to your local GS. You would be suprised how much contact rings make if everything is not just right.
BB

skinewmexico
September 14, 2007, 11:51 PM
Burriss Signature Zee rings.

Outlaws
September 14, 2007, 11:56 PM
Not to be rude, but how can you buy a 375H&H and not spend the money for quality rings? That is a round that costs about $2 a shot. I would think $50 for even mediocre rings would be nothing in the long run.

Are you using the standard rings that are see through? On a 375H&H you will want the scope as low on the rifle as possible because the extra hight will increase the force exerted on the rings. How big is the scope? It isn't upwards of 50mm so you couldn't go lower if you wanted to is it?

GunTech
September 14, 2007, 11:59 PM
You rings are too big - tightening them will not help. Get some heavy duty rings with torx screws. What sort of base do you have?

You can try putting a piece of masking tape inside of the bottom ring, but I doubt it will help.

dstorm1911
September 15, 2007, 12:47 AM
as stated ya gotta match the rings to the cartridge, .357 H&H grade rings are gonna run ya bout another $75 don't over look the mounts as well..... what kinda glass did ya put on it? I ask cause once the rings/mounts are solid that recoil is getting transfered fully to the scope next if its not up to it ya are going to be very dissapointed.

Zerstoerer
September 15, 2007, 03:56 PM
Thanks for all the feedback, Gentlemen.

It is a Bushnell Legend 5-15x40 scope on Medium size rings.
Mounted on a T/C barrel with a T/C mount. The Legend is advertised to take
.375 H&H recoil.

I will look for some better rings - but which ones are especialy for heavy recoil? Steel or Alloy?

I am using the new Flex tech stock and recoil is not too bad - like a 3" 12 Ga. out of a lightweight shotgun.

My reloaded round costs me about $.75 ea.

Anybody have any experience with the 'Talley' One Piece base for T/C Encores with integrated base?
(Cabela's ZW-21-5802)
Seems to take care of the alignment, but it is still alloy.
Is it common to use some kind of 'liner' to prevent ring to scope scratches?

Thanks again.

Outlaws
September 15, 2007, 04:12 PM
Is it common to use some kind of 'liner' to prevent ring to scope scratches?
You can buy a lapping kit and lap the rings. But I think once you get good rings and the scope stops sliding you will not have that problem as much. I mean, if you mount the scope, then remove it later, there might be a few markings were the rings were, but without seeing your scope right now I would assume the scratches you got are exaggerated from the poor ring connection.

I am not familiar with the Encore so I can't really go into what is available for bases and rings.

50 Shooter
September 15, 2007, 06:01 PM
Just a caution, if you do decide to lap your rings don't over do it. Thinking that you need to have the rings lapped perfectly smooth is where you'll make the mistake and ruin the rings.

R.W.Dale
September 15, 2007, 06:16 PM
Anybody have any experience with the 'Talley' One Piece base for T/C Encores with integrated base?

If you go with this style of ring on a 375H&H encore you WILL implant your scope into your forehead, and it will hurt a lot. This style mount doesn't allow you to mount a scope far enough forward to provide for enough eye relief. This style base should only be used on light recoiling rounds

In the pic below you can clearly see how the ocular is placed out over the cheekpiece with the scope mounted forward as far as possible.

http://i3.photobucket.com/albums/y96/krochus/encore/HPIM1659.jpg

HankB
September 15, 2007, 06:23 PM
I have a Leupold 6x42 mounted in a Redfield JR mount and rings (Pilkington lever release on the rear ring) on my .375 H&H and haven't had any problem.

The Redfield mount base originally had 3 holes, but I had a 'smith drill a fourth hold to match the receiver, so it's held on with 4 screws.

I lapped the rings for full contact and then coated the inside of each ring (both top and bottom) with rosin. I dissolved the rosin in alcohol and "painted" it on with a Q-tip to get a very, very THIN coat.

Tightened it all up, anchoring the screws with blue Loctite . . . no problems over several hundred rounds.

DnPRK
September 15, 2007, 06:53 PM
Lap those rings to provide maximum contact surface. Degrease the rings and scope tube with isopropyl alcohol and apply a tiny dab of urethane glue on the lower half of the ring.

Works with a 458 Win Mag.

308win
September 15, 2007, 07:05 PM
If you aren't going to put better quality rings/bases on the rifle - or even if you do - one trick that often works is to put a small dab of silicone calk on each ring half. Tighten them down and let the calk set before shooting.

gipperdog
September 15, 2007, 08:51 PM
I have a .338 Win Mag that I had been using Leupold rings & mounts that had the large windage screws on the back mount. I was told that with the heavy recoil of the .338, that it was much better (stronger & safer) to use dove tail mounts both front & back. That way there was no way that the mount to scope contact could shear off. For what you're doing, I'd go that way & make sure the mounts are steel. Alloy's just can't hold up to that much recoil over time.

def4pos8
September 15, 2007, 11:28 PM
Better quality rings can help. My .375 H&H Ruger #1 uses a ring set from Earnst Appel of Vienna (EAW). The smith that fitted them used a fine honing grit set in epoxy to make certain the the rings would NEVER let go of the Kahles scope that sits in them.

That scope hasn't budged in twenty years. I suspect it never will.

That fellow's service was not without expense but I do not regret paying the bill. ;)

Macgille
September 15, 2007, 11:36 PM
Loc tite makes a compound that is expressly for cylinders. It will lock the scope to the rings and never slip. But be warned, in order to remove the loc tite you will have to heat the rings to 275 deg. f. I would find a set of rings that fit better, steel rings.:)

ranger335v
September 16, 2007, 10:10 PM
tight?

ranger335v
September 16, 2007, 10:19 PM
Don't bother with electrical tape, it will squeeze and creep under the pressure with time and heat.

All the above are workable solutions but...maybe some over kill? Especially using the valve grinding compound, that SHOULD stop it from slipping but, if it does even a little, your scope will be badly scarred.

Try lapping the rings to achieve maybe 80% contact. To provide a better grip, dust a bowling ball type rosin bag on both sides of two strips of newsprint that's been cut to fit neatly inside the rings. Clean both the scope and rings with alcohol, insert the paper and screw things together normally. I think that will fix your slipping problem with no potential for scope damage.

But, if you want a full mechanical lock, loosen each ring slightly, apply a drop or two of cheap Super-Glue in each ring and snug them back down for keeps.

Either way, a drop of oil on the rings for rust protection is unlikely to affect the security of the scope after things are drawn down tight.

Zerstoerer
September 16, 2007, 10:51 PM
Thanks again,

I have a new steel T/C mount coming with steel torx rings.
They are verticllay split - will try your advice.

SUBMOAS
September 16, 2007, 10:58 PM
First thing you need to do is degrease those rings and scope. Take a paper towel and spray some on it. Take the towel and clean the inside of the rings. You will see that the paper towel will come out brown. Also do the screws. Wipe down the the scope tube where the rings are going to mount.
Take a Q-Tip with degreaser and do the screw holes.
Hope this helps......

Zerstoerer
October 9, 2007, 12:34 AM
Got the T/C rings and base installed with the 'Torx' screws.
Promptly over 'torxed' the ring screws - three out of four cracked after what I would consider only medium force.
Took it to my excellent Gunsmith who was able to drill out the broken screws, cut threads for lager ones and also coated the scope with some kind of abreasive powder inside the rings.
Scope now 100% solid and rifle shoots where it should - got it adjusted to be on Mil-Dot high at 100 yard.
Was able to smoke the metal chicken at 200 meters.

Thanks for all the help.

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