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Discussion Starter #1
The recoil spring on my USP9F seems to be binding slightly. When I pull the slide back it snags slightly about half-way but will continue back fully after that.

Has anyone else noticed this?
 

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This is normal. If you pull off the slide, you'll notice that the USP has a double recoil spring, the first is the full length of the guide rod, the second (contained within the first) is only about half the length and does not engage until the slide reaches that point.

So what you feel is the slide pulling back until it reaches the second spring, at which point the resistance increases.
 

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Discussion Starter #3
This is normal. If you pull off the slide, you'll notice that the USP has a double recoil spring, the first is the full length of the guide rod, the second (contained within the first) is only about half the length and does not engage until the slide reaches that point.

So what you feel is the slide pulling back until it reaches the second spring, at which point the resistance increases.
The hitch that I'm feeling definitely happens before I reach the second spring. It seems more like the main recoil spring is catching on the second recoil assembly.
 

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This is normal. If you pull off the slide, you'll notice that the USP has a double recoil spring, the first is the full length of the guide rod, the second (contained within the first) is only about half the length and does not engage until the slide reaches that point.

So what you feel is the slide pulling back until it reaches the second spring, at which point the resistance increases.
That is incorrect. The secondary spring doesn't engage until the very last part of the slide travel. Pull the slide back till you normally pull it, than really pull hard and you'll feel the secondary spring.

As for spring binding, there's not much you can do. You can try a new spring. The spring doesn't slide around the guide rod like in other guns.
 

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Discussion Starter #5
That is incorrect. The secondary spring doesn't engage until the very last part of the slide travel. Pull the slide back till you normally pull it, than really pull hard and you'll feel the secondary spring.

As for spring binding, there's not much you can do. You can try a new spring. The spring doesn't slide around the guide rod like in other guns.
So what I'm feeling is probably normal then?
 

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The recoil spring on my USP9F seems to be binding slightly. When I pull the slide back it snags slightly about half-way but will continue back fully after that.
It's not snagging. What you are experiencing is the engagement of the shorter second spring. Over the first half of the slide's travel, only the large spring is compressing. Afterwards, both the large AND the small spring are being compressed. That's why there's a noticeable change in tactile perception.
 

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Discussion Starter #7
It's not snagging. What you are experiencing is the engagement of the shorter second spring. Over the first half of the slide's travel, only the large spring is compressing. Afterwards, both the large AND the small spring are being compressed. That's why there's a noticeable change in tactile perception.
This is definitely not the case. It doesn't reach the shorter spring before I feel the hitch.

I think it has to do with the orientation of the spring on the recoil assembly, if I orient the spring so that it is pushing downward and touches the frame, I don't notice the hitch. If it is turned sideways it is very noticeable. The only thing I can come up with is the main recoil spring is snagging on the shorter assembly when it isn't oriented correctly.

Let me ask this, when installed the slide on your USP full size, do you notice the recoil spring bowing downward and touching the top part of the frame when you slide it on?
 

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Let me ask this, when installed the slide on your USP full size, do you notice the recoil spring bowing downward and touching the top part of the frame when you slide it on?
Yes, if positioned that way (bowing downwards) it would touch the frame. However, I usually orient the spring to be bowed to the side because I don't like the idea of a metal spring rubbing against the polymer frame.
 

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The recoil spring is hitting the guide rod where it retains the smaller recoil spring.
 

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That is incorrect. The secondary spring doesn't engage until the very last part of the slide travel. Pull the slide back till you normally pull it, than really pull hard and you'll feel the secondary spring.

As for spring binding, there's not much you can do. You can try a new spring. The spring doesn't slide around the guide rod like in other guns.
I think that was what I was trying to say, but looking back at what I posted, it's not very obvious :p
 

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If you can shoot with no problems, then their is no problem. I too feel the spring to be somewhat stagey. This has been consistent with all the USP's I've had.
 
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