I've been looking to buy a used fixed magnification Leupold of either 4x or 6x magnification. When it comes to the 6x models there is a lot of variation. Is there much difference between the 6x33, 6x36 and 6x42 in practical use? ... For that matter from 33 to 42 is it a profound difference in brightness?
I'm wondering if I should seek out one model specifically or just buy the first one that comes along at a good deal.
FWIW, I�ve measured the eye relief on many scopes over time, including the fixed 6x ones I currently own. The measurement technique is easy to learn and is described on page 60 in Mule Deer�s (John Barsness) excellent book �
Optics for the Hunter.
Here�s a list of the optimum eye relief values measured on several of my 6x scopes:
Scope Make/Model/Build Year, Eye Relief (inches)
Leupold M8-6x Compact (non AO), 1983, 3 & 5/8
Leupold M8-6x 36mm Standard, 1993, 3 & 7/8
Leupold M8-6x 36mm Standard, 1990, 4
Leupold M8-6x42mm, 2004, 4 & �
Leupold FXII 6x 36mm, 2010, 3 & 7/8
Burris Fullfield 6x, older, long tube model, 3 & �
Note: all of these eye relief measurements were taken AFTER each scope was carefully focused for my eye - YMMV.
As to brightness, all of them are good enough to shoot accurately before and after legal hunting hours here in MT, and that includes cloudy days in the timber. However,the 6x42 is the brightest one of the bunch but it only edges out the older M8-6x36 model by a small amount - not significant by my standards.
However, IMO the M8-6x36mm scope is a very flexible one in terms of mounting options. Its main tube is fairly long (not as long as the Burris), and the small diameter ocular and objective lens housing let it be positioned lower to the receiver. The small size of the objective lens housing also helps when you need to clear a rear sight, something that can be a problem with the large objective housing on the 6x42 model.
But the compact M8-6x scopes also have their place. I put mine on a classy rimfire rifle after sending it back to Leupold to have them reset the parallax setting to 75 yards.
As for which one to put on your 30'06 FN Mauser, my first choice would be the standard M8-6x36 due to its mounting flexibility, and the fact you should be able to find a used one in good condition for less $$ than a 6x42. But I wouldn't pass up a good deal on a 6x42 if the scope was in good condition and built on or after 1990 with Multicoat-4 (X or later prefix SN, or any of the suffix SNs).
