by B.B. Pelletier
Fresh from the closet, another fine Crosman 160 emerges into daylight. We’ll watch this one blossom.
Today, I’ll report on the cleaning of Jose’s Crosman 160 and the adjustment of the trigger. This rifle was quite rusty when I got it, so today it came out of the stock for a thorough cleaning. The barreled action comes out of the stock by removing one nut on the bottom of the forearm and by removing the safety switch. To remove the switch, it must be turned toward SAFE while you push it out of the triggerguard. It will pop right out when you get it in the right position.
The broken safety has been pushed out, and the nut removed from the stock. That’s a new safety to the left of the broken one. The barreled action is now ready to come out of the stock.
Once the action was out of the stock, I could see that it was far rustier than I originally thought. The rust that could be seen when the rifle was intact was just surface rust, but the stock was hiding deep active rust that had to be removed.
This was under the stock — heavy, active rust that must be dealt with!
I used Ballistol and a special scrubbing pad I bought at a recent gun show. A friend of mine says this pad looks like a stainless steel pot scrubber. All I know is that it removes all the rust and doesn’t harm the blue.
I used Balistol in a spray bottle and a special metal scrubber to remove the rust.
I was surprised at how fast the rust was removed. In all, it probably took no longer than 15 minutes to completely clean all the metal parts.
With the gun finally clean, it was time to address the trigger. I mentioned in Part 1 that this trigger is one of the finest ever put on an inexpensive air rifle, and it can be adjusted to a very light, crisp pull. When I got the gun, the single-stage trigger had lots of creep and was breaking at 5 lbs., even. Something had to be done about that.
The Crosman 160 trigger is an adaptation of a 15th century crossbow trigger, where a rotating piece called a nut forms the sear that releases the hammer — in the case of the pellet rifle. The nut is a lever that’s shaped like a circle. It allows a small force (the sear) to overcome a greater force (the hammer spring) through leverage. No filing or stoning of the trigger contact surfaces is necessary, because the trigger doesn’t work like a conventional one.
From Sir Ralph Payne-Gallwey’s book, “The Crossbow,” (published in 1903) this illustration of a 15th century crossbow nut shows how a great force can be overcome by a smaller one.
But the Crosman 160 trigger is more sophisticated than the crossbow trigger. It allows the adjustment of the sear contact area and also the point at which the trigger stops. This gives the shooter a safe trigger that breaks cleanly, yet feels like an expensive precision target trigger.
The trigger in the subject rifle was about as filthy as I’ve ever seen. This trigger has a sideplate that allows the user to watch the adjustments of the parts and even to cock and fire the trigger with the parts exposed. Normally, this sideplate keeps the parts inside pretty clean, but you can see from the photo what I saw inside this one.
I’ve removed the trigger unit from the action here. It isn’t necessary to do this, and in fact you must be able to cock the rifle when you adjust the trigger, so leave it connected. I did this for cleaning purposes.
Compare this photo to the previous graphic, and you’ll see all the important trigger parts. This is before cleaning. The rusty red part at the upper right is the nut that’s the sear.
I removed the trigger blade from the trigger assembly and cleaned it outside the trigger box, but all other parts were cleaned where they were situated. Ballistol on cotton swabs worked wonders at removing the rust, dust and dirt. And it left all the parts with a lubricated surface.
The two trigger adjustment screws were stuck in place by dried grease, so Ballistol had to dissolve that before I could clean the threads. The final touch was to apply moly grease to the mating surfaces of the trigger blade and the rotating nut that serves as the sear. Then it was time to adjust the trigger.
The first step was to back off the trigger return spring, which is located at the bottom rear of the trigger box. With this spring relaxed, you can feel the engagement of the sear much better.
Next, I adjusted the top screw, which adjusts the trigger/sear contact area. I set it very quickly because I’ve adjusted dozens of these triggers over the years and I know what they need. You may have to adjust the screw then cock the rifle and fire it several times to get the engagement you want. The engagement needed is very narrow, and it looks like the trigger is about to slip off the sear; so I always give the cocked rifle a bump test after adjusting the trigger, just to be safe. If I can’t jar the trigger off the sear, it’s safe.
The final screw to adjust is the trigger stop or overtravel screw. It stops the trigger blade after the sear has released, and the closer this is to the release point without impeding the trigger-pull, the better the trigger feels. Once the engagement area is okay, it’s easy to set this screw to stop the trigger immediately following trigger release.
With that done, I put the cover plate back on the trigger and shifted my attention to the S331 sight. By the way, Robert of Arcade explained in a comment that the S331 sight was actually made by Mossberg and not by Williams, as I originally said in Part 1. I changed the maker to Mossberg in Part 1, and now I’m telling you.
The rear sight on this rifle was loose when I examined it, so I removed it from the rifle and disassembled it for cleaning. Most of the parts are aluminum, but a couple are blued steel and suffered from rust to the point that there were pits left on their surfaces after the rust was removed. The detents are very crisp and easy to feel as you make the adjustments. This is a simple peep sight assembly, but it works very well and adjusts precisely, which is all you can ask of a sight.
Once the sight was clean and back on the rifle, I put the barreled action back into the stock. I had to use the old broken safety switch because the replacement I have is slightly too large to fit the hole. I’ll trim it down in a separate session so the gun has a complete safety switch. For now, I’ll just keep the rifle off safe.
How does it look?
Because the bulk of the deep rust lies below the stock line, the deep pits that appeared from cleaning do not show. What was above the stock line was mostly just surface rust that’s now completely gone. The metal on this rifle now appears to be 80 percent or better. The stock finish is still flaky and needs to be taken down all the way with sandpaper and reapplied, but it doesn’t detract from the rifle’s appearance.
And the trigger?
The trigger now breaks at one pound, even. It’s glass-crisp, and you would swear that it releases at just a couple ounces if you didn’t see the trigger-pull gauge. I think the owner will be amazed at the transformation this rifle has undergone.
Yet to come
I won’t bore you with the other mundane jobs like the safety and the stock finish, but I’ll test this rifle for accuracy. So, there’s one more report yet to come. We already know the velocity is in the right ballpark — 656 f.p.s. for a 14.2-grain Daisy pellet on a 90-degree day. But I want to show you the accuracy these old rifles can give with modern pellets.