found some answers

September 25 2008 at 1:17 AM
kornphlake  (Login kornphlake)

Response to Shadow tune questions

To answer some of my own questions I decided to take a stab at dissasembly and see what I'd be setting myself up for. First thing I notice is that the screw that holds the barrel is incredibly difficult to remove. I ended up having to use an impact driver (the kind that looks like a big screw driver you whack with a hammer) finally I broke the screw loose, I thought I was going to strip the threads out or break the head off. Upon closer inspection it looks like the head of the screw may be tapered and makes a taper lock with the tab on the action. Once I finally got that screw loose the rest came apart pretty easily. The pin that holds the rear spring guide is knurled on one end, not knowing this I pounded the knurl all the way through, when I finally got the pin out I realized that it would have been a lot easier to remove if I'd only pounded it out from the other side.

The answer to question 1 is:
Yes a spring compressor is necessary to remove the trigger assembly, without removing the spring guide it's impossible to get the trigger assembly out.

The second question is still a mystery to me, but I did discover that the spring has an odd bend to it about 1 inch behind the top hat, is this normal or should it be replaced now? I've got to admit I was expecting a lot worse before I opened the gun up, what I found was that a lot of care was taken when this gun was assembled. I couldn't see any major damage to the piston seal, the only thing I could see was what looked like a blemish where the sprue was cut from the seal after molding, the sealing edges looked very clean otherwise, I've never seen a new seal so I'm not sure what the edges should look like but the leading edge of the seal had a slight radius that may be a result of wear. The cylinder looked very well polished, there were some sharp edges on the slots cut in the cylinder but I decided to leave them alone until I get a replacement spring and seal. The rear spring guide seemed to let the spring rotate freely, the contact surfaces were well polished and lubricated, between the top hat and piston is a plastic spacer that serves as a bearing on that end, again all surfaces were well lubricated and nicely polished. I'm not sure how much of the polish came from just breaking in the rifle and how much came from the factory but I feel like it would be a waste of time to try and improve anything on either end of the spring aside from maybe cleaning up the sharp edges on the spring.

A broken bar clamp would probably work for a spring compressor, a working bar clamp works well too. I had to preload the first couple inches then slide the clamp into place as there wasn't enough travel in my clamp to go from uncompressed to fully compressed, it wasn't a big deal for me though, at least not with an old spring, a new spring that hasn't been set may be a different story.

I'd still like to know if the Maccari springs really give better performance or if it's just knowing that you spent more money on a boutique spring that makes it seem better.

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  • Answers - Jim on Sep 25, 2008, 10:03 AM

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