Glare-Cutting Donut Filters for Front Globe Sights
Gear Review by Germán A. Salazar, Contributing Editor
All of us have at one time or another struggled with glare in the front sight at certain ranges and certain times of year. There are a lot of ways to deal with glare, shade tubes being the most commonly seen. I prefer to avoid any type of extension on the front or rear sight, especially anything that hangs past the muzzle where the muzzle blast can cause damage and in any event, I haven’t found those tubes to be very effective. However, the need to do something about the glare at our south-facing range at the Phoenix Rod & Gun Club has become essential for me. At this time of year, the sun is directly in front at this range and I really struggle to get a clear sight picture.
The photo above, taken on 10/16/2010 clearly illustrates the problem at PRGC as the early morning sun is from the left and front. Note the backlit flag and the direction of the shadows. As the sun continues to rise, it aligns itself right down the range towards the shooters. Apart from the glare, the bull is hard to see on the targets once they’re up because the light is coming from behind the target, not from the front. A very challenging set of light conditions which will worsen from now through February as the sun stays lower in the sky month by month.
Anti-Glare Filters from Art Neergaard
I recently spoke to Art Neergaard about this problem. Art manufactures a number of innovative products for rifle sights through his company ShootingSight LLC and he had an idea for me. The idea was simple in concept, a “donut” filter for the front sight with a hole in the middle so as not to darken the already dim bull and yet, it would cut the glare that otherwise enters the front sight. The picture at left shows the filter mounted on the sight. When you’re looking through the sights, there isn’t the large gap around the aperture, it’s actually a very close match. Sticking the camera right into the sight obviously changes the perspective a bit.
I wanted to evaluate the Centra Goliath 30mm sight on my new Palma tubegun. Since Art intended to make the filters for the 30mm size, this was a good time to begin that evaluation as well. My last match score with this rifle, five weeks ago before the light got bad, was a 600-42X, since then, I’ve had a couple of poor matches with other rifles as the light and glare have really troubled me. With the 600-42 as a “good condition baseline” with this rifle I was eager to see how the filters would work.
Art sent me a few items: two filters (one gray, one orange), and one filter-holder for them, as well as a fixed aperture cut in the same material as the filters, with a beveled edge like the ones available for many years for smaller sights. The filters are interchangeable in the holder and can be changed in a minute or so. The aperture, however, is fixed as the hole is drilled in a lathe after mounting the disc in the holder — this ensures perfect concentricity for the aperture.
Gray Filter Preferred
Arriving at the range, I mounted the high-contrast orange filter first and looked through it. Frankly, although it cut glare well, I hate the look of an orange world! A quick change of filter and another look through the sights showed a good, glare-free and natural-looking sight picture with the gray filter. At right is a photo that shows the relative glare-cutting effect of the gray filter.
Scores Improved with Anti-Glare Filtration
Shooting a good mid-range .308 load with Winchester brass, Federal primers, IMR 4064 (manufactured in 1960, just like me) and moly-coated Sierra 190 gr. bullets, the rifle showed it’s good breeding giving me a 200-12X, 200-15X and 200-14X for a 600-41X, my 22nd score of 600! Well, quite a dramatic improvement over the last couple of weeks when I struggled to shoot 590, and back to the score I shot five weeks ago when the light was still good. Hooray! So yes, I’m very satisfied with the concept of the filter with a hole in it. All the extraneous glare that was hurting my sight picture was gone and the bull remained unimpaired. Not that the bull was too good to begin with as all I can see is a fuzzy gray blob out there, but keeping the center unfiltered was better than some solid filters I’ve tried in the past.
Clear Rain Filters for Front Sights
Art plans to make clear donut filters to use as rain shields for shooters with a front lens in their sight. That would keep raindrops off the lens — especially the middle of the lens where a drop could destroy the shooter’s ability to see the bull properly.
Filter Works with Fixed & Variable Apertures
Although I intended to try the fixed aperture also, I ended up shooting the entire match with the filter and the Centra variable aperture. I’ll try to use the fixed aperture (photo at left) next week. The value of a fixed aperture shouldn’t be underestimated. It provides a lower cost way to use a 30mm sight, an important consideration given the current $175 price of the adjustable aperture. Perhaps just as important, the fixed aperture is something that should be in every high-end shooter’s kit in case of failure of the adjustable, which has been known to happen. If I were traveling across the country or around the world to a match, you can be sure there would be a set of fixed apertures of various sizes in my kit to back up the adjustable iris.
But how do you know if your barrel is too hot? Consider a “non-contact” thermometer that reads your barrel’s “infrared signature”. The Kintrex or Actron pocket-sized, non-contact IR thermometers are ideal for shooters at the range or in the prairie dog fields. Both are handy and inexpensive — costing about twenty bucks (on sale).
