shimming a scope ??
 

Just a quick question on a scope. I've never had this problem with a scope before. I got a good deal on a Bushnell 4200 E-lite and decided to put it on my encore, so I took the Nikon 1.5-4.5 and put it on my Renegade. [Don't tell anybody]. Anyway I used some Weaver Grand-slam QR medium rings, but can't get enough height adjustment, still 5" low at 50 yds. Just wondering what is the best way to shim the rear of the scope base to get enough height? Do you think the problem would be in the scope or rings. Same base as with the nikon and hadno problem?????

RE: shimming a scope ??
 

I have seen some of the finest gunsmith's out there shim mounts before. But the bottom line is if you need to shim ascope then there is something wrong. A shim is simply a band-aid. It is not the proper way to do things. You need to figure out what the real problem is. All a shim wil do is put a temporary fix on a permanent problem.

Personally I have heard from several shooter's that the biggest problem with the Elite's is the lack of enough internal adjustment. How many minutes of adjustment does your scope have?? And if you are 5" low at 50 yards. At what position are your internal knobs at to be 5" low?? Tom.

RE: shimming a scope ??
 

First thing I have read they do is reverse the bases, from front to back. This will sometimes raise the scope. As for shimming, I have a gun smith do that.

RE: shimming a scope ??
 

All a shim wil do is put a temporary fix on a permanent problem.


+1

RE: shimming a scope ??
 

I did purchase a while back in the 70's from brownells brass shims for shimming a scope .
I think if you need to shim the bases i would use a aluminum soda can I think they are about 4 thousands
I have another idea try going up one size in the ring height

RE: shimming a scope ??
 

I agree, You should not have to shim a scope to get enough adjustment, it has to be the rings, it is a one piece weaver base that worked fine with the nikon scope. I am going to swap rings with another rifle and see what happens. THANX FOR THE REPLYS !!!!

RE: shimming a scope ??
 

I install a lot of scopes on guns.All Simmons rings, some Leupold rings andmost Weaver rings are being made in China: Not sure about your QR rings-have not installed a set lately.Had so much trouble with these made in China rings thati willnot attempt to install them on a gun.

RE: shimming a scope ??
 

I'm not sure if the problem is with the encore, but it sounds that way. The mounts are installed directly on the barrel, right? If it won't shoot high enough, the problem is with the mounts. You say you will try new mounts, and that's probably best, but as Cayugad said, sometimes swapping the mounts front to back will help. I don't know about that particular scope, but some can be damaged if shot when adjusted to the end of theadjustment range.

RE: shimming a scope ??
 

So what exactly is the permanent problem? One can put on a different set of scope mounts and the problem very likely might disappear altogether. I wouldn't call this a permanent problem just a compatibility problem between the gun, the scope mounts, and the scope. There might be some rifles that would need shimming with any mount or scope you might put on them, but I think such rifles are not very common. The use of a thin shim on such rifles will absolutely not alter the guns reliabilty one bit either.

RE: shimming a scope ??
 

The permanent problem is probably the mount.

RE: shimming a scope ??
 

No problem with the mount.

RE: shimming a scope ??
 

The problem is not the rings, the mount, or you. The problem is T/C. While I like their guns (both of my often-used MLs are T/C guns), this is a KNOWN, FREQUENT issue with the barrels used on the Omega and Encore. Now, some people probably bottom out the adjustment on the scope, get it to zero, and forget about it. I know a few of those. Others can't get enough adjustment or, like me, dial up at longer ranges and can't do that when the adjustment was all used to zero.

The problem is inherent in the barrel of these guns!!! There is no permanent fix outside of buying a different gun!

You have two options:
1) Get Burris Signature rings. These use plastic inserts (half-circle rings) which go inside the ring and hug all around the scope. The 30mm ones come with inserts pre-cast to cant the scope one way or the other; you can use them to introduce a downward cant to the scope to reduce the amount of clicks you need to zero the scope. I LOVE them, I use them on all my scopes. The 1-inch ones do not come with the offset inserts, you must buy a set separately.

2) Shim the back of the scope base. Use the curved face of a soda/beer can and trim so it sits under the base nicely. I used 3-4 layers and drilled a hole so the rear screws guarantee they stay in place.

My long-range Omega uses both of these mechanisms to maximize the upward travel I have. A buddy of mine just shimmed his Encore and shot it at my place last week...worked as I guaranteed it would.

RE: shimming a scope ??
 

I'm no gunsmith, obviously, but I can't understand how this could be attributed to the barrel.

Isn't the surface of the barrel where the scope is mounted parallel to the bore? And, isn't that the case with many similarly designed guns on the market? If so, it would not seem that the barrel could possibly be to blame.

Are you saying that the bores of T/C barrels are pointing downward in relation to the part of the barrel where the scope is mounted?

I'm just not aware of anything else that could cause this "known, frequent" problem. If this is a known problem, enlighten me to what is wrong with T/C barrels. Thanks.

RE: shimming a scope ??
 

Barrels are tapered, not the same diameter from breech to muzzle. Typically, the mounting surface where the screws are located is left parallel to the bore (if the scope mounts directly to the barrel and not a receiver). Apparently, this is not the case on Encore/TC barrels, resulting in a base/ring/scope assemble tilted a few thousands of an inch.

The location of the scope mounts on these guns is also a little unconventional -- rather than having forward and rear screws for the mount, both sets are positioned relatively close together towards the rear end of the mount. Perhaps this has something to do with the slight angle that results, I don't know.

You're making alot of assumptions to arrive at the conclusion that it can't be the barrel. How many of these guns do you own? How many different mounting systems have you tried on them trying to solve this issue before arriving at this conclusion? I personally own two Omegas with this problem, as I mentioned just helped a buddy with his Encore with the identical problem, in addition to half a dozen other shooting/hunting buddies with Encores/Omegas and numerous threads on this same issue on multiple hunting sites. I tried different bases, rings, and scopes, all of which failed to remedy the issue. T/C may not acknowledge to you that the problem is known, but anybody who spends significant time shooting many of their guns knows about it. They're not going to publicize issues, just like when I called in about the front sight on my Omega X7 they cut me off and said they'd send the correct replacement before I even told them what was wrong with it. Apparently they know they were supplying them with front sights too short to zero, but now 2 years after I bought mine I have heard of more people still having the same issue.

Next time you get access to an Omega or Encore where the Burris rings have not been used or has not been shimmed, count how many clicks are above where it shoots to 100 yd zero and the number of clicks below. I bet you will find it is nowhere near the optical center, as it should be.

RE: shimming a scope ??
 

You say the T/C barrels are tapered toward the muzzle. I don't know if that's true, but I can believe that. You also say that the area where the scope is mounted is tapered. Again, i can't say.

But if the area where the scope is mountedIS tapered, then the scope would be tipped downward in relation to the muzzle, correct? That would cause the gun to shoot high, not low. After all, as you have indicated, the fix for a gun that won't shoot high enough is to shim the rear mount up. The guy that originally posted could not get his gun to shoot high enough.

If his barrel was indeed tapered as you say, then his problem would only worsen if it were not tapered. I guess T/C doesn't taper the barrels enough.

I am not an expert, but I know the problem of the gun not hitting high enough cannot possibly be blamed on barrel taper and a scope tipped slightly DOWN. Not physically possible.A scope tipped up would cause the gun to hit low, but then the taper would be running in the wrong direction.

What other mystical properties do T/C barrels possess that all the similar CVA designs don't?

I don't own one but I do know a lot of guys that have and I've read plenty of posts on T/C guns. I can't say I've heard much about trouble getting them to hit high enough.

RE: shimming a scope ??
 

Hey guys, I didn't mean to stir up a hornets nest with this question. Sometimes the problem might be the same but the cause is different. Anyway I tried different rings (warne QR) and got the same thing, shooting too low. I guess my Nikon scope had more adjustment than this Bushnell.There is a slight gap at the front of the base and not at the back, meaning the barrel starts to taper before the end of the base. My Omega is not that way, tight fit from front to rear. I called Bushnell and got no satisfiaction at all. The lady said you might have to use some shims. I asked if there was some internal adjustments that needed to be made and she just said NO. All I can do is put the scope on a different rifle or shim the base. For a 300.00 scope you shouldn't have to modify anything.

RE: shimming a scope ??
 

Interesting. If there is a gap in the front between the base and the barrel, that suggests to me that the base is probably still parallel with the bore. Hard to say from here.

At least you know how to shim to fix the problem in the short term.

And I'm not stirred up, I'd really like to know what's wrong with T/C barrels that makes them shoot too low with scopes. One thing is for sure, it isn't barrel taper. Could be something else though.

It would be interesting to see where a bore laser sighter would project a beam in relation to your crosshairs when the scope is set to its center. That would be telling I think. Do you have access to a bore laser? They do make them for MLs.

RE: shimming a scope ??
 

Mounting a scope on the barrel is definitley not the ideal way to mount scopes. No doubt. However the main problem with the Encore and Omega is that the front and rear holes are too close together. The mounts need to be "stretched" out a bit.

Personally I would not consider the cheaper Weaver base on my Encore's. I have mounted scopes on well over a dozen different Encore's. However I prefer to use the Warne bases and rings. The Warne bases and rings are longer and stronger.

We have been shooting scopes on MZ's for over 20 years. There are inherent problems with a MZ that you just do not have with a 700 Remington.

When I have used the Warne bases and rings with a good quality scope I do not have any problems with the Encore-or any other MZ for that matter.

Switch to a Warne base-you can still use your Weaver rings. This should take care of your problem. But shimming is definitely not the answer because one person says that Encores have that inherent problem with their barrels. If you continue to have a problem with this then check your scope, or send the barrel back. There definitely is a problem, and the best thing to do is find the problem, and fix it, not put a band-aid on it.

To demonstrate the length difference I have a picture of the Warne vs. the Leupold base. Tom.

RE: shimming a scope ??
 

Like unclenorby said, if there is a gap at the forward end of the base and the barrel is tapered the base probably is parrallel to the bore. And maybe I should try a warne base instead of the weaver. Anyway, I was at Sportsman's Wharehouse tonight and talked to one of the guys that mounts their scopes and he said I should just bring it in and they could play around with it to find the problem. So I think next week when I am in town I will bring it along. Will let you know what happens.

RE: shimming a scope ??
 

It depends which way the taper goes -- is the front of the base higher or lower than the back. I do not have sensitive enough tools to tell whether the issue is this, or something that happens because as I stated the two sets of screws are unusually far back on the base.

As the OP indicated, when mounted the front of the scope base is slightly separated from the barrel. It is not hard to imagine, then, why the gun is shooting low if indeed the entire mounting surface is parallel to the bore (it is nothing more than an assumption to say that since there is a gap as the barrel tapers that the base must be parallel to the bore). Shimming the back removes this gap and fixes the problem, more or less. At least, for the 4 guns I have had personal hands-on experience fixing. So, for some reason, the entire mounting surface is not flat and parallel to the bore. The base ends up pointing slightly up. If you are so curious as to the "mysterious" properties of T/C barrels I suggest you get a micrometer and figure out the EXACT cause for yourself and us all.

To insinuate it can't be the barrel because similarly designed CVA guns don't have this problem is a bit silly, isn't it? The barrels are made by different companies to different specifications -- they are similar in cosmetics only. Does CVA use the same screw mounting system? That is like saying a Remington 700 can't have a certain problem because a Winchester Model 70 doesn't have it. C'mon now...

RE: shimming a scope ??
 

How is shimming a "band-aid"? Would installing a base with a machined cant, like long-range shooters do, similarly be a band-aid? My gun has been wearing its band-aid for about 6-7 years now and shoots MOA or better to 400 yards. I don't see anything sub-optimal with this setup, and a soda can is a hell of a lot cheaper than going through more rings and bases, or paying to send the barrel back and hoping the one you get back is a) lacking the problem, and b) as accurate as the good one you sent in. And that you get it back in time to tune and hunt with it yet this year.

Band-aid indicates temporary, something you will have to mess with in the future. If you shim a base correctly you will never have to mess with it again unless you take it off the gun. It is as permanent as any scope mount.

RE: shimming a scope ??
 

I always check the conditions of the rings if they need Honing or shimming. If you don't check these conditions you will Tweak the scope when tightening the screws down...Most of this has been taken care at the factory on high $$ bases and rings......

If I am going to hone them, I have a 1"X8" SS round stock and mix some Jewelers Rouge (NOT GRINDING COMPOUND)with 3 or 4 drops of 3-in-1 oil and apply it to the round stock. When I tighten the caps down, I work the Rod back and forth until the high spots are removed. I wipe the rings down real good and try the RingAligner. Ifpoints still don't align Then I start the Shimming process until the points align.....Remember to always tighten the screws in sequence.

RE: shimming a scope ??
 

Shimming a scope is fixing a problem that should not exist!! If you can not understand that then I can not help you??

So yes, you are either temporarily fixing the rifle, or you are perrmanently avoiding the problem. Tom.

RE: shimming a scope ??
 

The tapered barrel simply cannot be the cause of the gun shooting low. It could only cause the gun to shoot high. That's why thelong range shooters can use machined bases, to get the extra range.

Look at it this way. Imagine your gun is hitting dead on. Then put a big shim under the rear scope mount. This would cause the scopebe "looking"downward in comparison to what is was before.You'd have to raise the gun to get the crosshairs back on target, and you'd shoot high.

RE: shimming a scope ??
 

ken farrell make bases with built in MOA, if you dont want to try the burris ring thing

RE: shimming a scope ??
 

Or it simply can, if the area low is where the back screws mount, causing the scope to tilt UP in front. This was pretty clear in my previous post I think.

RE: shimming a scope ??
 

Shimming is as permanent as the mount you put on the gun. Temporary implies that it will need to be redone at some point. If there is a problem with the barrel causing the scope to be misaligned, there is no permanent (by your definition) fix short of replacing the barrel. I'm still unclear why shimming the base or using Burris Signature rings is so bad in your mind when the end result is exactly the same -- a rifle that shoots accurately and can be sighted in hear the scope's optical center. Please explain to me why this is so bad.

I'm not disagreeing that you can send it in to T/C (on your own dime) and hope they fix it. And then potentially send it in again (on your own dime) if they don't get it right. And hope this all leaves you time to get ready for hunting season next month or so.

Or, you can shim (for nothing) or put on rings designed to fix this problem (for about $30) and be done with it. I don't see why either way is right or wrong. Personally I have just not had good enough luck with most company's customer service (including T/C) to screw around with Option #1 when I can permanently (by my definition) fix it myself.


It's like when I was not happy with the 3-inch groups and wandering POI my Omega shot from the factory. The problem was the contact between the action and stock; now I could have sent it back to T/C and fought with them about it trying to get the problem fixed. But I'd already paid TWICE to send the stock back because the front swivel stud pulled out with finger tension (they did finally fix it right to their credit, after like 3 months of back-and-forth) so I was not about to throw good money after bad. I took 2 evenings and bedded the stinking stock and was done with it, sub-MOA gun now and it cost less than shipping it back to T/C again.

Perhaps I'm more inclined than some to tinker. Perhaps I just don't have the patience and money to go back and forth on minor gunsmithing issues that anyone with a screwdriver,drill,and pair of pliers should be able to handle. Please explain to me what is so terrible about shimming a scope base or using canted rings?

RE: shimming a scope ??
 

If the "area low is where the back screws mount, causing the scope to tilt UP in front", then certainly the gun would shoot low. I agree completely.

That situation is entirely different that what most would call barrel taper.But, call it whatever you want, a "low area" in the vicinity of the mounting holes seems like a bad thing, and likely notan element of the design. If it does exist as a knownfrequent issue, that would seem to be a QCproblem.

RE: shimming a scope ??
 

After talking to some different people and reading what I could on shimming a scope I decided to put a .016 aluminum shim under the back two mounting screws on the weaver mount. The only option I had left was to try a different base which I might do in the future. One of the ones with the peep-sight on the base. I tried a piece of plastic shotgun shell first to see how much I needed .036 which was too much so I got some .016 aluminum stock from a hardware store and made one. The scope is adjustedabout 1/3 of the way up from center and here are the results. A little bit of wind today, the fifth shot was out of the group ????




I did snug all the mounting screws up the same and put some locktight on them.

The gap between the front of the base and the barrel was cut in half after the shimming which is only because the barrel starts to taper before the end of the scope base. I'm pretty sure the bore and the scope base are very close to being parallel now. I think a couple clicks left and up and we will have it. But as always everything will be checked and double checked before going out in the woods.

RE: shimming a scope ??
 

If you decide you want to buy one of the bases with the peep sight on it(EABCO), let me know. I have a brand new base and ring set that I would sell. Make me a reasonable offer and I will sell them to you. I was going to put them on my Encore MZ, but I ended up getting rid of the Encore, and bought a Knight LRH. Tom.