Hawkeye Borescope

The Hawkeye knows—much like the Shadow, for those of us old enough to remember the classic radio program. Trying to see what is inside the bore of your firearm is as difficult as casting a shadow in the dark. No matter how much light you send down one end of the bore you still cannot actually see what is on the inside walls by looking down the other end. With the Hawkeye borescope this problem is solved. Before proceeding, be absolutely sure that all firearms are unloaded and the action is open.

Make sure muzzleloaders are not loaded by measuring the distance a ramrod can be inserted in the barrel. I recently acquired a Hawkeye Borescope from Midway USA, the Classic Slim Kit made by Gradient Lens Corporation (gradientlens.com) located at Rochester NY. It came complete with everything needed to see 17 inches down the bore in either direction. It is housed in a very sturdy aluminum case that is foam lined to keep the borescope, Maglite attachment, mirror tube, and cleaning supplies separated and protected.

These parts can be purchased without the case, but it is well worth having. At first I was a little intimidated in using the scope for fear of damaging it, but it is a sturdy piece of equipment that can withstand years of use with sensible precautions. The rigid tube kit comes in two sizes, the "Hardy" and "Slim" measuring 0.250 inches (6.35mm) and 0.165 inches (4.2mm), respectively. Obviously, for those of us that want to scope .22 bores and larger the Slim version is best suited to our needs.

The scope comes in smaller diameters for those who wish to see into .17 caliber barrels, but they are more expensive. Length of the scopes run from two to twentytwo inches. Most gunsmiths will opt for the 17 inch models which allow looking inside almost any barrel by inserting the scope from the breech and muzzle ends. A mirror tube is included in the kit that allows the user to see the bore at a 90 degree angle. It slides over the scope tube and is rotated to change views.

The image is reversed through the straight eyepiece due to optical necessity and the tube has a small notch in the rear to indicate which direction you are actually looking. This lens and mirror are of very high optical quality and care must be taken not to shove them into oil or other crud that may be in the barrel. A lens cleaner and swabs are included in the kit. The light source is supplied by a common Maglite flashlight that screws into the eyepiece.

The company offers a stronger light called the Super NOVA but, so far, I have not seen a need for it in most gunsmith applications. And what are the gunsmith applications for a tool such as this? First and foremost, how clean is your bore, really? I now know I have sent out rifles that I thought to be free of any fouling whatsoever that had streaks of copper on the lands and grooves that would have shown up by using the Hawkeye.

I’m not saying the rifles were dirty but they could have used a little more work to be absolutely clean. Did accuracy suffer with these firearms? I’ll never know but it’s possible even though all of them were hunting rifles and not benchrest types. Does your traditional muzzleloader have a bad case of leading due to firing Maxi-Ball or other pure lead projectiles using a common lube like Maxi-Lube? There is no way to tell unless a scope is used.

I’ve been interested in muzzleloaders ever since I was a boy, which was along time ago. My father took me every Sunday to the local gravel pit to shoot clay pigeons with original double-barreled 12 gauges. A young boy like me was impressed with measuring the powder and tamping down a wad, pouring the shot and putting down another

wad, seating two caps and busting the pigeons. I had great fun when I got to load dad’s gun by neglecting to put any shot in one of the barrels. When he missed I think he knew what I did, but he always acted surprised and said he thought I was on that one. I took a look into my Thompson/ Center Renegade .54 caliber muzzleloader the other day and was not really surprised to see a lot of lead deposited in the bore.

I bought this gun at the height of the replica muzzleloader hunting seasons that were just coming up in the early eighties. The instructions were to slaver a lot of grease over the Maxi-Ball and shoot. I did kill a deer with this gun and that load, but I had an idea leading had taken the edge off whatever accuracy was possible with that type of firearm. Now I know. The chamber of a bolt-action or single-shot rifle can easily be inspected with this tool. How smooth is it?

Has it been torn up by a "chattering" reamer? Is there an area that looks like alligator skin directly in front of it that shows erosion from pouring many shots down a hot barrel? Is the leade smooth or ragged as a hobo’s handkerchief? The Hawkeye has the proof and can instantly diagnose many problems that trial and error experimentation would take weeks to uncover. Tool marks in the lands and grooves of the bore can have a profound effect on accuracy and fouling. Can the barrel be lapped? Did the lapping help?

The Hawkeye gives you a pretty good idea. I inspected the bore of a Ruger .45 Colt the other day. Halfway through the six-inch barrel was a ring caused by firing around while another bullet was accidentally lodged in the chamber. This was done when the customer used a progressive reloading machine and somehow didn’t get any powder in one of the rounds. The energy from the primer alone was enough to push the soft lead bullet halfway into the bore.

When he fired the next round he had two bullets going down the bore at the same time and caused the ring. Luckily no one was injured and the gun is still chugging away without any noticeable difference in accuracy than it had before the incident. Thank goodness he wasn’t using hot loads or it could have been a different story. The uses for a Hawkeye are myriad. Anywhere there is a hole you want to inspect is fair game. Checking reloading dies to see if they are scratched is an option.

The inside bolt locking recesses of the typical hunting rifle are impossible to inspect without a tool such as this. You get the idea. I also purchased one of the camera adapters that securely clamps on the Hawkeye eye piece and allows the gunsmith to have a permanent record of fouling, tool marks or whatever damage may be apparent. Using this option is well worth it when explaining to a customer why he or she might need anew barrel.

The camera adapter is ordered by the size of your lens and actually screws into the lens for a secure hold. When ordering, get the same size as the filters you use, such as 58mm. You lens should have this information printed on it and the adapters can be ordered in almost any combination, so it’s not a big deal. I found that by using a 18-55mm Canon lens that the image printed too small to get a full frame. I solved this by using some tricks with my photo editing software to trim and adjust the image.

The Gradient Lens website states that the best lens to use for this application is a telephoto in the 300mm range. I don’t have one on hand but I think this will solve that problem. As far as the lighting goes, my kit is supplied with a common two AA battery Mini-Maglite available almost anywhere flashlights are sold. The batteries were included and were actually in date.

As stated before, the company does offer a brighter light but, so far, I have not had any problems associated with the Maglite, even for photography use. In practice the Hawkeye shows a relatively small viewing area, almost American Gunsmithing Association

like a microscope, and is detailed in its clarity as the scope features an adjustable-focus eyepiece. I found one of the easiest ways to use it was to follow an individual land and groove as I rotated the mirror tube down the bore, something like following a spiraled railroad track or a roller coaster ride. This way, spots you may want to revisit can be easily found if you note the depth of the tube at that juncture.

One other accessory I purchased was the 90 degree eyepiece adapter which allows the viewer to see more easily where the straight tube may be blocked by the stock, such as when scoping the bore from the breech end. It is not an inexpensive tool but it is worth it for convenience. As far as I can tell the camera adapter will not work with the 90 degree eyepiece. Gradient Lens Corporation makes many different kinds of borescopes.

An interesting variation is a flexible scope linked to a laptop computer that allows you to see images in real time on the computer screen and save this as a video for a permanent record for future comparison. These kinds of tools area little too rich for my blood but some gunsmiths, especially barrel makers, may benefit from having one. The company makes tools for medical applications as well as manufacturing needs. Thank goodness it has not forgotten the shooting market.

Gradient Lens has a contact number and, of all things, you actually get alive person on the telephone. I had a few questions and they proved very helpful. If you damage your borescope the website states that repairs are priced reasonably and turn around time is slight. I have no reason to disbelieve that statement.

If there is anything I would change on the tool that I received it would be to have the mirror tube graduated in inches so as to make the spots in your Care must be taken to keep it clean and undamaged. bore you want to revisit easier to find. As it is nowa witness mark generally provided by a grease pencil for easy cleanup is required to mark the depth of the last view. A microscopic spot is a lot easier to locate repeatedly using a good reference point.

Also, it would be nice if one could use the 90-degree eyepiece with the camera adapter. The stock will block your view most of the time when you are using the straight eyepiece if you are viewing from the breech. In all fairness, the action can be removed from the stock to eliminate this problem. I really don’t see how I got along without the Hawkeye all these years.

Of course, we didn’t have such tools when I started but that is no reason not to embrace technology that is helpful when it is available, especially when it is simple and user friendly. AG

Reader Grab Bag This is in reference to the Reader Forum, March 2012 and a few other tidbits. My thanks to Dave Bennett at Brownells. The ones who wrote in about the Enfield being drilled for a scope mount, claiming it should not have been drilled behind the top lug, must not have ever seen a Springfield 1903-A4 sniper variant. Or around top Sako Browning. I guess the manufacturers of those guns didn’t know they were doing wrong.

In more than 51 years of gunsmithing I have never seen a rifle action fail because of a hole being drilled behind the top lug. I’ve never seen one in which the headspace is excessive. Some of the old German rifles had a large dovetail cut into the front ring for the claw mounts and still had no problems. The man who taught me gunsmithing never had a problem with where to drill and tap a rifle.