What does the term mean

M

macv

Guest
Hi, what does the term mean " locking up the scope". How is this done, and for what reason. To me it would seam that it would now be set that you could no longer adjust it in any way. That's probably wrong, but, I sure would like to know. Thanks.:confused:
 
It means to glue parts

The internal moving parts are glued in position to preclude POI changes. Along with this "freezing", one must have an adjustable mounting system in order to set windage and elevation. Attached is a picture of my 36X Leupold in its TSI (Gene Bukys) mount. If properly installed it is very reliable. Good shooting.... James Mock
 

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Macv, use the Search feature if you want more detailed information about the subject. There is a recent thread, very long, and very descriptive, about locked up scopes.
 
A frozen( locked-up) scope in fixed mounts can be invaluable when
scope issues come up. It can be a real eye opener
 
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Macy

First, a little history.

Through the years, the accuracy potential of the Benchrest Rifle has grown to the extent that having a sighting system that is 100 percent reliable in holding Point of Aim is paramount. In fact,it just might be the single most important factor in solving the "accuracy equation".

The vast majority of scopes have internal adjustments that include an erector tube. This tube usually has a pivot on one end, and is held against the adjustment knob abutments, by springs. There in lies the problem.

If the erector is not held firmly in place so that there can be absolutly no shift in it's position, (we are talking zero), then issues will occur. Remember, if that tube just shifts .001 inch inside that scope, that could mean more than 1/8 inch on the target.

Scope manufactures did a good job for years, but problems did occur. Several notables came up with fixes to shore up the enternals and help stabilize the erector tube assembly. The most popular of these is the Cecil Tucker Conversion for the 36X Leupold.

In around 2004, shooters started designing a system that would utilize a scope that had the internals 'frozen', to be used in conjunction with a mounting system that allowed the shooter to adjust the Point of Aim externally.

Many of us figured out a way to diss-assemble and freeze the more popular scopes, (Weaver and Leupold), and others started manufacturing external adjustable mounts. The most notable of these is the TSI and Brackney. The Jewel, which was the first, was popular for a while, but the person manufacturing the system quit, and they are no longer were available.

In the mean time, Leupold recounted their efforts to make a scope that was more reliable. From what shooters say, the current crop of Competition Leupolds are quite good. Then, March came onto the scene, with a commitment to building scopes that were 100 percent reliable in holding Point of Aim. In fact, that was the premier aspect of their product, to finally address this all important issue. They are the only manufacturer that is willing to step up and say this in their advertisments.

The fact is, any scope with internal adjustments, if subjected to recoil long enough, will probably develope issues with the erector tube's stability. Much of this centers around the "gimble" mount that secures one end of the erector tube, and allows the tube to pivot. The more popular Japanese, (and probably more accurate "Chinese"), manufactured scopes share a gimle mount that is pretty light in construction, the sperical register surfaces are fairly thin. Abuse will losen it up. How doIknow.I have seen it first hand.

The big question is, "are scopes really as bad as we all thought". The answer is, some are, and some are not. If you have a scope that is 100 percent reliable, then life can be very good. However, if you have a scope that does have Point of Aim issues, Benchrest can become a very frustrating endevour.

Many shooters will say, "I have used such and such for years, and never had a problem". They also never won many matches. Some shooters simply buy brand new scopes every season, and consider a scope a disposable item. But, I have taken brand new scopes of a popular brand apart, only to find that they were not up to standards.

I have no idea, (percentage wise), how many Scopes that are designed for 100-200 yard Benchrest have Point of Aim issues. I do know that one company, March, specifically addresses this. If you read a Advertisment in any magazine concerning scopes, you will notice that they all avoid the issue, except for March. Keep in mind, all other aspects of scope performance are really a non issue if the thing shifts Point of Aim. In fact, the scope is useless for what we do if it is not 100 percent reliable.

I do know this. I have had every popular scope brand apart, (except for March), and it doesn't take long to see what can go wrong. Keep in mind, these are massed produced items that are required to to do a seemingly impossible task, that being, satisfy the needs that are demanded in 100-200 yard Benchrest. That is no easy task.

I can say that I have had two scopes in my career that I was 100 percent sure had issues. This is what convinced me to go to a Frozen Scope and Jewell Mounts back in 2005. I have since since come up with my own internal fix for the 36x Leupold, (sort of a modified "tucker" conversion), which is what I have atop my new 6PPC Sporter at this time. My 30BR mounts a 50x March, and it seems to be very reliable.

Are frozen scopes and external mounts reliable. Yes. The current World Champion, and new 200 yard LV record holder, Gene Bukys, uses his own TSI System in conjunction with a frozen 45x Leupold. That sort of speaks for its self.

The March is probably the best option for an unmodified scope if you want to ba absolutly sure that the optics are 100 percent reliable. There are rumors that shooters have had problems, but no shooter has come out and publically and admitted to any. I thought I had an issue with one of my Marches, but March said it was ok. They even sent me pictures of the scope completley diss-assembled, and the final testing. That is the one that is on my 30BR at this time. I sold the others because, in all honesty, the optics are not up to par. I am saving up to buy a 40x March. which from all accounts, has the best glass of the lot, it even rivals the optics in the 45x Leupold. 40X is plenty of magnification for what we do.

It is difficult to advise shooters whan it comes to scopes. Nothing is more frustrating than to waste an entire shooting season, changing barrels, bullets, powder, and everything else, only to discover that the real culprit was a scope that was adding .050 to every group. Many shooters will say that it is all in our minds, but I have been there, and done that. They also say, "well (popular name), uses this brand, and has never had problems". Are you getting the same scope he gets?? We hear all sorts of rumors, In all honesty, I don't know.

If you are interested in a frozen scope and external adjustable mounts, contact Gene Bukys, who uses the TSI System.

The only internal adjustable scope I would feel confident in recommending for Benchrest would be the March. Of course, they cost a lot. But, they are the only major manufacturer that says that their primary goal is to produce a scope that will stand up to the demands of 100-200 yard Benchrest. That means, holding Point of Aim, 100 percent of the time. Untill the other manufacturers are willing to do this, it is difficult to give a recommendation.........jackie
 
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I think that after

what Jackie had to say, I won't have to do any more searching. He pretty much told me what I needed to know. My, how this bench rest game differs. So much to learn in so short a time. Should have started long ago. High power seems like such a kids game now. But it was a blast. Thanks "all" for such good information. Have a great "shooting" year.
 
Frozen Scopes on a stick.

Macy, Here is my take on frozen scopes. You need objective evidence you have a scope problem. I used a Hood scope checker recently on 6 scopes and a reference scope for a total of 7. Five were Leupold competition models (4 45's and one 40X dots 1/16 & 1/8) and one was a 40X March, 1/8 minute dot. The reference scope was a Leupold 36 BRD with an 1/8 minute dot. The scopes were aimed at the piece of graph paper on the target board on the corners of different squares. These aim points are marked on a piece of identical graph paper on the shooting bench. Fire the rifle. Re aim the reference scope on its aiming point and observe the check scope dot position vs the old aiming point. The difference, if any tells you if and how far the scope is shifting impact point. Do this 5-10 times. Turn the vertical and horizontal adjustment knobs on the check scope to a new aiming point and repeat. All the scopes were fired on a LV rifle. All shifted impact points after adjustment of the knobs on the check scope. the shift was random and about 1/16 minute. This shifted aim point then became stable and remained so for the rest of the shots. All the scopes were then stable. No further point of impact changes were observed. I have heard of others who had radically different results then mine including one profoundly moved gentleman who set the new world record for the international scope throw after a distressingly failed scope checker trial. The point is this: Check your scopes to see if you have a problem. Tim
 
Tim Oltersdorf said:
Macy, Here is my take on frozen scopes. You need objective evidence you have a scope problem. I used a Hood scope checker recently on 6 scopes and a reference scope for a total of 7. Five were Leupold competition models (4 45's and one 40X dots 1/16 & 1/8) and one was a 40X March, 1/8 minute dot. The reference scope was a Leupold 36 BRD with an 1/8 minute dot. The scopes were aimed at the piece of graph paper on the target board on the corners of different squares. These aim points are marked on a piece of identical graph paper on the shooting bench. Fire the rifle. Re aim the reference scope on its aiming point and observe the check scope dot position vs the old aiming point. The difference, if any tells you if and how far the scope is shifting impact point. Do this 5-10 times. Turn the vertical and horizontal adjustment knobs on the check scope to a new aiming point and repeat. All the scopes were fired on a LV rifle. All shifted impact points after adjustment of the knobs on the check scope. the shift was random and about 1/16 minute. This shifted aim point then became stable and remained so for the rest of the shots. All the scopes were then stable. No further point of impact changes were observed. I have heard of others who had radically different results then mine including one profoundly moved gentleman who set the new world record for the international scope throw after a distressingly failed scope checker trial. The point is this: Check your scopes to see if you have a problem. Tim
Click to expand...


What Tim said, and this time he is not spinning one of his usual fables...........Don
 
Interesting how things come full circle. So this just proves my Fecker and Unertl scopes have the right idea. he he :D
 
Larry

Not really. The current crop of external adjustable mounts hold the scope solid, as opposed to the Unertl system that allows it to recoil. This allows for a mounting system that is extremely light in weight. Combined with a frozen scope that can weigh as little as 13 ounces, the shooter can add weight in other locations on the Rifle..........jackie
 
Unertl Externally Adjusted Scopes

I have an Unertl on my Martini and Kimberly has a Fecker on her Anschutz. While it is true the scopes can be allowed to float in their mounts, there is a spring that can be progressively tightened to the point that all scope movement ceases. On the other hand some shooters let the scope float freely and simply pull it back into battery after each shot. The main advantages of the Unertl/Fecker/Lyman external adjustment system are the isolation of the scope from recoil forces and the stability of the non movable crosshairs.

I follow the middle ground and keep enough tension on the spring to have the scope reset itself after each shot. Every few shots, I manually check to be sure it is returning precisely to battery.

Still, for serious long distance Benchrest shooting a system like what Gene Bukys has developed sounds interesting. If I ever have enough cash for a serious Benchrest rifle and a March scope, I just might give it a try. :D
 
Gut tells us

that the only effect of motion that affects the scope is the rearward recoil of the rifle. That is very decieving and wrong. The low frequency and one way shock of the rear moving recoil is very small in energy and amount of damage it causes compared to the higher frequency parts of the shock. I have instrumented MANY guns of all kinds and surprisingly the vertical and lateral shocks are almost 50% of the inline levels above 500 hertz. That is where most of the damage and movement of scope parts happens. The fact that the old unertl can "float" front to back really doesnt help it out much.
 
While not as competitive as many of you, and certainly not in the same class of shooter as many of you, I have struggled with understanding scope shift and have come to a conclusion as to what causes the shift described herein once knobs are adjusted. I find it easier to visualize this by looking at an externally adjusting scope.

Once a given zero is obtained for a beginning point of impact, look at the position of the round scope tube in the three-point adjustment system. The three points being the vertical and horizontal contact points and the spring loaded position point.

Unless it is pure coincidence, the scope tube will be off-center in the three point system with respect to both windage and elevation. Of particular importance is the elevation eccentric, because if the scope tube is not contacting the windage pressure point at EXACTLY the 3 o'clock position, when the vertical adjustment is moved, windage will be affected as the windage pressure point progresses "around" the tube. And even if the initial tangency is at the 3 o'clock position, the surface area of the windage contact point is limited and extreme vertical adjustments will move the windage adjustment tangency, thereby changing more than just the vertical adjustment.

No copyright or patent claims here, but I have visualized a solution. Whether for internal or external adjustment scopes, this should provide the same solution. Where the three point adjustment contacts touch the scope tube, the shape of the tube should be square rather than round. This could be as simple as adding a cube shape at the contact position. In doing so, the initial eccentricity does not matter, as any movement of either vertical or horizontal results in the tube movement being either just vertical or just horizontal.

Is it really that simple, or am I really off base on the cause of the tracking error? And then maybe you all knew this already. Thank you for your time.

Dan
 
Thank you.

I considered this as a PM but apparently you can post what you like w/o regard to civility. Thus I do likewise.
JerrySharrett said:
Deadwood learn to use the Search feature;
http://www.hitmill.com/internet/searchengines2.html
Click to expand...

Your link has absolutely no relevance to searching a Bulletin Board or Forum.

It is blatantly obvious YOU have NEVER used the BRC Search utility, had you done so, you would recognize the sheer foolishness of suggesting others do.

No wonder you call yourself deadwood!!
Click to expand...
I do because I live in Deadwood, SD and my first name is Richard which makes it perfectly suitable… as does yours.
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Dan

"Tracking" is of no use to a 100-200 yard Benchrest Shooter. I could care less if it shifts a tad to the right or left when I adjust the verticle, or if it shifts a tad up and down when I adjust the side to side. What I AM interested in is that the scope stays dead put once I stop turning knobs, (after a few settleing shots).

If it will not do that, it is useless for what we do.......jackie
 
Jackie:

I understand why tracking is of little use for benchrest, as you suggest. I wasn't very clear in my explanation. It is my belief that the round tube and contact points also contribute to torsion that does not allow complete movement of the tube after adjustment until after a few shots are taken, thereby demonstrating POI shift. I feel that the shift is due to the completion of the adjustment movement a few shots after the adjustment is done. This will cause problems during benchrest use.

regards,

Dan
 
Dan

Most Erector Tubes have spherical sufaces on that part of the erector tube that the adjustment knob abutments go against.

The reason most scopes take a few shots to "settle in" is because of slack in threads, the gimble joint pivot having to settle, and the erector tube settling against the abutments.

As I said before, I don't care if it takes a few shots to settle the Point of Aim, as long as it stays there after it finally settles in. Many do not......jackie
 
stiller said:
that the only effect of motion that affects the scope is the rearward recoil of the rifle. That is very decieving and wrong. The low frequency and one way shock of the rear moving recoil is very small in energy and amount of damage it causes compared to the higher frequency parts of the shock. I have instrumented MANY guns of all kinds and surprisingly the vertical and lateral shocks are almost 50% of the inline levels above 500 hertz. That is where most of the damage and movement of scope parts happens. The fact that the old unertl can "float" front to back really doesnt help it out much.
Click to expand...

That makes complete sense. Still the fact that the crosshairs of the Unertl scope are factory frozen does take away one Achilles heel that internally adjustable scopes all have in common. One less thing to vibrate loose and go wrong.

I have seen quite a few very old Unertl, Fecker and Lyman externally adjusted scopes that work quite well and would be awesome, if they only had modern lenses, materials and the extremely close manufacturing tolerances that are possible today.

My younger brother has a CNC machine shop. Whatever you say, only a true artist, of a machinist can duplicate the quality his machines can turn out.

What I do not understand is why no one produces an externally adjusted benchrest competition scope with solid click stop focus for the common range distances. I do not enjoy searching for the perfect 100 yard focus as my old eyes go in and out of focus, while looking through the scope.
 
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