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Crosman Nitro Trigger Adjustment

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Author Bill Clarke


This article is taken from the Pyramyd Air Report written by B.B. Pelletier:

Two weeks ago, I attended a field target match in Wappinger Falls, New York, while filming American Airgunner. The club is run by Ray Apelles, his wife, Laura, and his father, Hans. The match was shot in a downpour, which dampened spirits a might, though field target isn't like baseball. You're never rained out, only rained on--sometimes.

While the match was running, Ray invited me to try the trigger on his brother-in-law's Nitro Piston SS rifle he was competing with. He warned me it was sensitive, so I tried it with my very best 10-meter-pistol trigger finger, and sure enough, Ray was right. It was a splendid pull! I shot the rifle only a couple of times because the match was still going on. I figured I would report about what a wonderful trigger tune Ray had achieved, but that would be the end of it. Then he dropped the bomb.

"I didn't tune that trigger. I just adjusted it," is what he told me. Well, I've been party to wishful thinking in the past, so I was still skeptical, but I vowed to try to adjust the trigger on my test NPSS when I returned home. And if there was any merit at all, I would report it to you. I did, there is, so I am.

Oh, oh!

In rereading my report on the NPSS, I see that I praised the trigger for being so crisp. I actually guessed its pull weight to be a pound less than it really was, which was 3 lbs., 12 oz. And I also tried to adjust it. This is ironic, in light of today's report, so I'm quoting exactly what I said in Part 2:

Just for fun, I adjusted the screw a full turn in each direction, but the only thing that changed was the length of the first-stage pull. The pull-weight remained constant. The second stage was also mushier after adjustment in either direction until several shots had been fired. Then, the crispness returned.

That is exactly what happened, but the problem was that I didn't go far enough. This time, I turned the one and only adjustment screw three and one-half turns counter-clockwise and got approximately what I felt on the other rifle. I have to tell you that I didn't arrive at this on the first try. It took several attempts before I got the second stage where I wanted it. At one point, it was adjusted out of the trigger-pull altogether, so don't give up until you arrive where I'm reporting.



There's the one and only trigger adjustment screw, behind the trigger. Turn it counter-clockwise to reduce the second stage, as described in the text.

Since we know what the trigger measured before this adjustment, you'll be just as astonished as I was to learn that it now breaks with the exact same force--3 lbs., 12 oz. And yet I feel it is so much better that I'm making this special Part 4 report. What gives?

Preload

What gives is a special technique that, until now, I'd only seen in expensive target pistol triggers. Some of the pull weight is loaded into the first stage. After it has been pulled through stage one, stage two only requires a few ounces of effort before it breaks. Or at least that's what it feels like. When I measured it, it took exactly 34 oz., or just under 3 lbs. to break. So, why am I so excited?

Because this trigger is glass-crisp! If you want to feel what a glass rod feels like when it breaks, set the NPSS trigger up this way and try it.

What to expect

When Ray warned me about the trigger, he was inadvertently making it possible for me to shoot the rifle correctly, because I try to set up all my 10-meter pistol triggers the same way--with most of the pull weight in stage one. So, I'm prepared to pull carefully through a heavy first stage until the trigger bumps into a light stage two. Most shooters find that very difficult. They pull and the trigger feels mushy until it suddenly lets go with no warning. They haven't trained their fingers to feel for the light second stage.

With the NPSS trigger adjusted this way, stage one is very long and heavier than most shooters are used to. Stage two is there, but the moment the trigger contacts it all pulling has to stop. That takes some learning to get used to the feeling. But after you know how it works, the trigger is superbly crisp when set up this way.

I know the numbers I'm reporting don't seem like much of a change. But when you try it, you'll see what a huge difference this adjustment makes. Believe me, if it didn't make a huge difference, I wouldn't have reported it.

617 Rating: 2.7/5 (53 votes cast)

Comments
More information  
A good thread can be found at: http://www.network54.com/Forum/275684/thread/1263046543/Nitro+NPSS+Trigger+Question

Posted By: Bill Clarke
10 January 2010 13:17


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