Friday, December 30, 2011

Riflescopes

Last year, I bought a Redfield 4-12x40mm Accu-Range scope.  You may recall that Leupold bought the Redfield name a while back, and now uses it for what is effectively a cost reduced (in the cosmetics and optional features) Leupold hunting scope.  I bought it partly because I have an older Bushnell 4-12x40mm scope with a bullet drop compensator for my M1A.  Unfortunately, it no longer focuses crisply above 10x.  This somewhat defeats the point of having a rifle whose effective range is...in excess of my abilities to use it!  (Every tool you own should be more capable than you are, so that you have room to grow into it: that's my maxim.)

Anyway, I bought the Redfield because I could not find anyone who seems to be willing to try and repair the softness of the Bushnell for less than the Redfield cost--and to be blunt, I suspect that this Leupold-made Redfield will probably last longer than the repaired Bushnell.  Friends with expertise in this field indicate that Leupold's startling reputation is well-deserved; I am sure that the U.S. military buys Leupold scopes for reasons other than to make a fashion statement. 

So I will ask one more time: any ideas where something like this can be repaired at a reasonable cost?  My guess is that there is a bushing somewhere that holds one of the lens in position, and that bushing has corroded or deteriorated, causing the lens to move slightly--just enough to make it soft.


UPDATE: Now that I have the scope out of the rings, I have spent some fiddling with it. While it is still a little soft at 12x, it is not as severe as I remember it--perhaps because I had forgotten that this is an adjustable focus objective.  You can adjust the objective for ranges from 150 to 1000 yards (which is effectively infinity).  While I am still not thrilled with the softness, it is not quite the disappointment that it was the last time I looked through it.

There are two aspects to the scope that distinguish it from the Redfield that replaced it:

1. It has a bullet drop compensator, which allows you to dial in the range of your target, and it adjusts the point of aim accordingly.  BDCs are approximate, since there are about five different dials, one of which fits 5.56mm and 7.62mm NATO, and of course, is necessarily going to be a compromise between those calibers (and a variety of bullet weights and designs).  I used to think that this was a very valuable feature on a long range target rifle, but the Redfield's Accu-Range reticle is actually almost as good: you adjust the crosshair point for 200 yards (for the NATO calibers), and there are a series of points below the reticle that correspond to 300, 400, and 500 yards.  Yes, this is less precise on the surface than turning a BDC dial to 450 yards, but unless you are using a laser rangefinder, or are on a range of known distances, you are going to approximating distance to target anyway.

2. The reticle on the Bushnell is this:




Those are the minutes of arc (MOA) between the various parts of the reticle at 4x, measured by putting these against a ruler at 24 feet, and then doing the math.  (Divide these MOA values by 3 for 12x, since this is not a front focal plane reticle.)  A typical exterior door is 36" wide; if the door is just about exactly 15 MOA (the width between the vertical line and where the horizontal line goes wide), that means it is 36/15 * 100 yards away: 240 yards away.  Most SUVs are about 70-72 inches tall; most sedans are about 65 inches tall; deer are typically 18 inches across the brisket.

The Redfield Accu-Range reticle, of course, has similar capabilities--but for reasons that elude me (but perhaps to avoid cannibalizing sales of their tactical scopes), the MOA values are not nice round numbers.  You can still use it, but it is very useful to have nice round MOA values when using the reticle for rangefinding. 

2 comments:

Michael The Magnificent said...

As an engineer, I have an innate desire to take things apart to see how they work. Once I've accepted that the object in question is broken and will be replaced, I've freed myself to tear it apart and make a last ditch effort to fix it myself.

So if you've already replaced it, and don't have all that much faith in it even if it were repaired, why not take it apart?

And if you do, please take pictures, not only to see how it goes back together, but to share with the rest of your readers.

augustrrr said...

Don't forget Clayton likes to see things on E-Bay. I bet he'd get less for a basket case scope than one soft at 10x.