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I know this might be an oddball question but I have a 52c with the standard scope blocks (7 1/4" spacing) that I'm working on and I'm wondering what kind of travel I might be able to get, looking to try some 250+ long range with the rig, I'm not opposed to getting a higher block but curious if anyone knows a ballpark area how far I could stretch the std mounts out with standard velocity
 

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chinaski: I noticed no one replied to your post, so I will throw in some comments. I can't give you the information you are looking for because I don't know the answers. I will say this though, I don't think there is a real accurate answer. The reason for this is based on the fact people would change the bases on their rifles for whatever reason and end with something far different than what was originally on the gun. Years ago with a couple of my 52B's I took the mounting blocks off the rifles and measured them and they were different from what was supposed to be on them from the factory. So what I did was install everything and head to the range with some decent ammo and test the elevation to see what I had at 50 yards. I set lowest elevation and highest and recorded the numbers. It should come as no surprise both rifles were different. I have since sold the rifles and no longer have the numbers. Windage didn't concern me, only elevation from min to max.

This was actually a fun test as I used the same Unertl 14X scope on both rifles and came away with completely different results. You may want to go this route and see what you come up with. As I recall the old external adjustment scopes had a lot of adjustment in them.

Rick H.
 

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I know this might be an oddball question but I have a 52c with the standard scope blocks (7 1/4" spacing) that I'm working on and I'm wondering what kind of travel I might be able to get, looking to try some 250+ long range with the rig, I'm not opposed to getting a higher block but curious if anyone knows a ballpark area how far I could stretch the std mounts out with standard velocity
Maybe you could make some shims to go under the rear scope block, maybe out of aluminum pop cans? Two or three shims placed under the block might get you the extra elevation you want. Or, shim the scope?
 

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The old external adjustment scopes were used for Forty Rod matches (220 yards).

My Lyman is good to about there, then I run out of vertical adjustment. Shim the rear base, get higher rear base, or get lower front sight base.
 

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The old external adjustment scopes were used for Forty Rod matches (220 yards).

My Lyman is good to about there, then I run out of vertical adjustment. Shim the rear base, get higher rear base, or get lower front sight base.
Having the rear base higher than the front one is the solution to using those scopes for longer ranges. But keep in mind that when you raise the scope at the rear base to shoot further you're lowering the front of the scope which may hit the barrel before you get enough elevation.

So you may need to get higher both front and rear bases to get on target at the range you want to shoot without the front of the scope hitting the barrel.

You can use a ballistics program to get a good idea of what angle the scope needs to be to shoot the distance you want.

Set up the ballistics program so it is on target at the range you are shooting but have the "steps" set at 1 yard.

Then look at how much the bullet moves upward in the first yard of flight. If the sight height is 1.5 inches at 0 yards the bullet is 1.5 inches below the line of the scope. If at 1 yard the bullet is .6 inches low (below the line of the bore) that means the bullet has risen 0.9 inches in the first yard. (1.5 - .6 = .9)

If you divided that number by 36 (the distance the bullet has traveled - 1 yard = 36 inches) you will have the ratio of rise to run (the slope). Multiply that number by the distance between the two scope bases, usually 7.25 inches, and you will have the distance the scope tube at the rear base needs to be above the scope tube at the front base.

The problem of having the front of the scope not hit the barrel is more complicated depending upon the distance the front of the scope is from the front mount and the size of the objective lens.

What I do is try dummy bases made of wood with the rear wooden base higher than the front base with the difference in their heights the same as determined above. Just tape or temporarily glue them to the barrel and then hold the scope on the two bases and see if the front of the scope hits the barrel. If it does make new bases that are both higher but still with the same differences in their heights until you're not hitting the barrel.

Before you hold the scope in place move the scope tube up in the rear base until it is almost to the top of it's possible movement but give yourself some room for error as this is a pretty crude method. (I'm assuming your trying to set all this up for the furthest target you want to shoot) Then you will be able to use the scope for shorter ranges with the bases you end up getting.

If you want to know what angle in degrees your working with take the number you obtained above for the slope (rise over run) and use a calculator that can handle Trigonometry and use the inverse Tangent function to determine the angle.

I hope all this helps. I have degrees in Mathematics and Physics and taught high school Mathematics for a number of years so this comes pretty easy for me.

If you need help don't hesitate to contact me with a personal message from this forum and I'll be glad to help you out.

I'm actually dealing with this same problem myself at this time.

Good Luck!
 

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Unertl

I shoot A LOT of unertl scopes.
I have a 52C with what I call the "Pencil barrel" its not the std. heavy target contour Factory blocks on a 7.2" spacing (See chart)
Shooting SK Rifle Match -red box-;
With a 3/4" 8x unertl and a 50yrd zero, I can get out to about 460ish yrds before I run out of travel.

Unertl block spacing chart
5.4" = 1/3" Per Click.
7.2" = 1/4" Per Click.
9.0" = 1/5" Per Click.
10.8" = 1/6" Per Click.
12.6" = 1/7" Per Click.
14.4" = 1/8" Per Click.

The new Malcolm scopes use different spacing to get regular divisions....I've never put a dial indicator on to if the thread pitches actually differ but their stated numbers, in print, differ from the old unertl spacing.
--------------------------------------------------------------------------------------------

Malcolm Gen II


For 1/4 MOA adjustments, the front and rear mounts should be
spaced 7.25" from center to center. The adjustment values will
be coarser when mounted closer, and become finer when
mounted farther apart.
Front to Rear Mount Spacing
(center to center)
Adjustment Value
per Tickmark
5.40" 1/3 MOA
7.25" 1/4 MOA
9.00" 1/5 MOA
10.80" 1/6 MOA
12.60" 1/7 MOA
14.40" 1/8 MOA


-------------------------------------------------------------------
MontanaVintageArms

"...mount spacing may vary from 7.00" to 12.00" at the
extremes. We recommend using 10.34" or 7.2" depending in the mount
configuration. This will give you .003" per MOA, or .002" per MOA."

(each line on the adjustment knob representing .001" of movement)

--------------------------------------------------------------------
Zero your rifle, estimare the drop farther out, in MOA, with your method of choice.
Count how many clicks you have to collision....Match available MOA of travel with corresponding drop.....That's your maximum range.
Hope this helps.
 

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Boy, some of these answers are making it hard. There is a lot of travel in the external scope adjustments.
Adjust your scope by shooting it at the range you want.
If there isn't enough adjustment shim the rear scope block with something about .005 to .010 thick. Keep shooting and adjusting until you get on target.
It is just that easy.
 

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I tried to compute long range sight settings for my rifle with a vernier rear sight. I gave up and decided to resort to testing. I used 50 yds because everything’s easier to see closer up. I started with the lowest setting and shot up to the highest setting. The target was 60 inches tall and had moa measurements every MOA. Using the same aim point I could easily determine the sight settings for MOA changes. The beauty with testing is I could see what are the MOA adjustment limits and if I wanted to refine changes for 1/4 MOA if I needed it. If my ballistics program told me I needed 22 MOA adjustment for 200 yds then I knew what seeting was needed and fine tuned from there. The problem with this testing method is it’s tough to do a cold bore first shot bullseye. I’m just a goober plinker, so no guarantees. I was previously an aero engineer and always preferred testing to computations.
 

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