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? I know the 42 will be breaking brightest and the 33 lightest but what about eye relief, eyebox, etc. 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.

I believe the 33 will have Leupold's compact style eyepiece which will decrease the eye relief compared to the standard eyepiece 36 and 42 models.

The 33 was marketed as a compact. The reduction in eye relief is good to know about since it will be going on a long action rifle and I don't care for offset rings.

Yes.

Other than that, the 6x42 M8 may or may not have Multi-Coat 4 lenses. In the early years it was single-coated. However, actual brightness will probably depend more on how much wear and tear the lenses have had (including shirt-tail cleanings) than coatings.

I've run a bunch of M8 6x's through my night test and unless the 6x42 was multi-coated the 6x36's have tested just as well. In fact the M8 6x36 (which was always single-coated) was a very bright scope for it's day--and unless the lenses were abused is still quite good today. This is probably due to efficient interior reduction of glare. I do know that 20 years ago the 6x36 M8 was noticeably brighter than the 6x32 Zeiss offered at the same time, despite the Zeiss's multi-coated lenses, when comparing brand-new scopes.

Mule Deer, thanks for the detailed reply. That is a lot more than I expected. Do you know what year the 6x42 got multicoated lenses?

Also since you have chimed in I'd appreciate your thoughts on one more thing. The scope will be going on what is for me a back up rifle of sorts. It is a JC Higgins 50 FN Mauser .30-06 with a McMillan stock I bought used on a good deal on the 24HCF classifieds and a Dayton Traister trigger I got in a trade. I don't have big money into it but it is a very good and highly accurate rifle. It is also about the sturdiest hunting rifle I can picture having. Based on things you've written I want a fixed magnification Leupold on it to complete the package.

I cover a lot of ground when I hunt but it could be open farmland or brush where more often I will carry a Cooper 52 .30-06 or a Marlin 1895. As the general purpose back up gun which fixed Leupold would you put on it? 4x or 6x and what version?

1990

I don't recall exactly when multi-coating appeared on the 6x42 but it as around 1990. You could probably find out from the Leupold website, along with serial numbers for different years. But in my experience it doesn't make enough difference in a 6x36 to consider, and the 6x36 is my choice for an all-around scope.

The big difference I've seen in the 6x36 M8 and FX-II is click adjustments. But if you don't care about that, or running the elevation turret up for longer ranges, the M*'s hold zero very well and are for practical purposes just as bright. Which is why I have around half-a-dozen 6x36 M8's on various rifles.

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).