Posts Tagged ‘Mossberg S331 peep sight’
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.
by B.B. Pelletier
Jacque Ryder is this week’s BSOTW.
Fresh from the closet, another fine Crosman 160 emerges into daylight. We will watch this one blossom.
I was at the rifle range yesterday, and a friend delivered an air rifle that another friend had asked him to give me. It’s a Crosman 160, and that’s a classic air rifle that I’ve never reported in this blog, so here we go.
The Crosman 160 and 167 (.22 caliber and .177 caliber, respectively) was first produced in 1955 and lasted until 1972. There were several variations of the basic model over the years, but most airgunners rank them by their triggers. There was a very simple trigger in the first variation from 1955 through 1959, then Crosman put out a very special variation with a super-adjustable trigger in the guns made after 1959. The gun I’m testing has this wonderful trigger.
At some time in the 1960s, the Air Force bought a large number of 160s that were fitted with a Crosman S331 peep sight (made by Mossberg) and sling swivels that held a one-inch leather sling. As chance would have it, several hundred of these rifles were discovered unused in a government warehouse in Maryland or Virginia in the 1990s, and Edith and I bought one. It was brand new and still contained the original Crosman CO2 cartridges that had been used to test it at the factory. I knew they were original cartridges because they were sealed with the patent-dodging “bottlecap” tops Crosman had to use for several years. The end flap of the box had the Air Force Federal Stock Number for the gun, and everything inside the box was new and untouched.
Still rusty and dusty from long years of storage, the Crosman S331 peep sight is a great addition to this accurate target rifle.
I reported on that 160 in The Airgun Letter several times, but eventually I got rid of the rifle. And until yesterday, that was all I had to do with a Crosman 160.
A shooting friend of mine told me a couple months ago about an airgun he had, and from his description I guessed that it was a 160. Yesterday, he sent it to me so I could examine it and tell him what he has. Jose — I have your rifle, and it’s a Crosman 160!
Yours is the last variation they made, which in all ways is the best 160 model to have. It isn’t a former military model, because they all have sling swivels and your rifle has no evidence of ever having them. But you do have the adjustable trigger and the S331 peep sight.
Your rifle has a lot of surface rust that I’ll remove with Ballistol and a special scrubbing pad I’ll show you in the report. I’ll also open the sideplate on your adjustable trigger and clean and adjust it for you. If it’s like the other 160 triggers I’ve adjusted in the past, I should be able to get a glass-crisp trigger-pull of a little less than one pound. I think you’ll be surprised!
Back when these air rifles were new, people thought they were only capable of putting 5 shots into a quarter at 25 feet. What we didn’t appreciate back then were the poor pellets we used held us to that level. Once world-class pellets became available in the 1980s, everything changed and these rifles suddenly became capable of putting 10 shots inside a dime at 10 meters. That is — if they had a good barrel.
Crosman made the barrels for the 160s. When they were good, they were very good. But when they were bad, they were horrible! I’ve heard tales of barrels with only half their rifling and even some that had no rifling at all! It isn’t common, but it happened often enough that old Crosman collectors know about it.
Pellgunoil works, again!
I installed two fresh powerlets and a LOT of Crosman Pellegunoil, and the gun held gas. I then fired 5 shots at a 50-yard target, just to see what kind of barrel it had. I got a group of about 5 inches, but it was a windy day and all I was trying to do was see if the barrel was rifled or not. It is. When I shoot it for accuracy, this rifle should do very well.
The safety switch is broken, which means I’ll have to use pliers on it, because it’s key to disassembling the rifle. The good news is that some plastic aftermarket safety switches exist and I may be able to locate one.
The big problem with a 160 is that it uses gas like a Hummer towing a house trailer! Typically, the two CO2 cartridges give about 30-35 good shots before they give out. Since they cost at least 50 cents apiece, a 160 can cost more than a .22 rimfire shooting good ammunition.
The solution is to convert the rifle to bulk-fill operations. That reduces the gas cost per fill to around 5-7 cents per fill. You still get the same number of shots and the same velocity, but the operating cost is much lower. Of course, you have to have all the equipment that’s needed for bulk-fill to do this, and that does cost some money.
Most 160s I’ve tested pushed 14.3-grain pellets out the spout at between 600 and 630 f.p.s. on an 80-deg. F day. It was about 90 when I shot through the chronograph at the range and the 14.2-grain Daisy pointed pellet (very similar to the current Precision Max) went through the Oehler skyscreens at 656 f.p.s. — right on the money! The rifle can be souped up a just a bit, but at the cost of increased gas usage. There’s really no convenient way around that.
By contrast, the Crosman 180 was a single-cartridge rifle that shot a .22-caliber pellet at around 575 f.p.s. and got about 40 good shots per cartridge. It was the favorite of many shooters. But the Air Force obviously didn’t care about how much CO2 they used, and the slightly more powerful 160 also had a better stock, a longer barrel and better sights. It was the obvious choice for a target rifle. I feel the procuring agency must have bought the gun, not so much for its accuracy but more for its much safer operation when compared to a standard .22 rimfire that was the normal target rifle of the time. A pellet rifle range could be set up safely in a gym, where a rimfire range required more safety measures.
The Crosman 160 is a .22-caliber single-shot CO2 rifle. It cocks on closing the bolt. It needs two CO2 cartridges to operate, though it will work with just one at lower velocity and with fewer shots.
The rifle weighs 6 lbs. and is 39-1/2 inches long. The barrel is 21 inches. The pull is 14-1/4 inches.
The rifle is mostly blued steel in a solid wood stock. The metal was not highly polished and I’ve always thought that the wood stock was some very clever kind of laminate, since it shows more grain than I think it should. I will show you the detail and let you be the judge.
The stock sure looks like a laminate to me.
I plan to clean the metal of this rifle and preserve it with Ballistol. I’ll open the sideplate of the trigger and show you the inner workings, then I’ll adjust the trigger to get it working as fine as I can.
Next, I’ll test the rifle for velocity with several pellets. I’ll also get a shot count for you.
Finally, I’ll shoot the rifle for accuracy at 10 meters with several pellets. I’ve examined the barrel, and the bore appears sparkling clean. The rifling is deep and everything looks okay. We should have some fun with this one.
Jose, you have a very nice air rifle, here. I hope you enjoy this report!