Canadian Airgun Forum

After doing a full disassemble and cleaning of my .177 Crosman Phantom I forgot to install the small washer that goes under the front spring guide. I literally noticed I had forgotten the washer right after everything was reassembled and loctite. Does anyone know if there is a draw back with not having this washer installed? I'm wondering about power loss specifically.

Thanks

I doubt you will notice any power loss. There may be some increased torque, but if the spring ends are polished up so the spring can turn freely, you probably won't notice that either. Phantoms respond well to tuning and lubing with the correct lubricants.
Put 100 shots through it and see how it performs.

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Two lathes and too many projects

Washer? I've never seen one on a factory Crosman like yours. So is/was your gun oem or possibly modified?
From your description is sounds like it was under the top hat, so between the piston and hat. Top hat being the short front guide with it's disc base. Is this a 500fps or full power? I ask b/c some people who have a 500 model with a hole in the piston will put a washer in there to block the hole. It's not an ideal way to do it, far from ideal imo.
Gotta pix of the washer?

Bought the gun second hand but I don't belive it was ever modified, it was in too good of shape. No hole in the piston but I know the spring must be shorter as I didn't have to use the compressor for this one. Here is the washer

Took a pic when I had it disassembled, don't know if this will clear anything up

It doesn't look like some random washer so maybe it was oem. Anyone else seen one in there?
Your piston is longer than full power which reduces the stroke, and the spring is likely weaker so both combined brings it down below the legal limit.
Whatever the case the missing washer will only cause a slight decrease in fps, nothing you'd notice w/o a crony. I'd just keep it and next time you're in there you can put it back, but it's pretty easy to do if you want to do it now.
You can even shim it up more if you want but to stay legal you'd need a crony to verify it.
Btw the full power springs wire is .122", yours looks pretty thin, like maybe .094. If you want to go full power you'd need to cut your piston shorter and get the stronger spring. Cocking effort would probably double.
Even the full power spring is compressible by hand, and pretty easily imo.

I finally bit the bullet and took it apart again, this time the washer's in there. Btw what is meant by "shim it up" in regards to the spring? I read this in practically every air gun forum and for the life of me I can't figure out what it means. Thanks for all the info

It just means to use that washer, any washer(s) or whatever as a shim to increase spring preload which increases its force on the piston all the way from the start to fully cocked. People do the same with valve springs on engines, if you know engines at all. Normally a gun has little room to shim, like only one or two washers. What happens when you shim more than that is the same that happens in a car eng, it coil binds, meaning it's bottomed out on its own coils and can't be compressed any further. In a car you bend parts, in a gun you either cannot cock it b/c the piston stops before the trigger can catch it, or you bend your cocking linkage trying. So you shim as far as you can and are still able to cock it to net max power.
In yours you have an extra long piston so you're far from coil bind. I rekon you could shim it a full inch, but as mentioned you have the legal limit to deal with. Seems fps is fairly random based on posts, but many are a good chunk below the limit so I'd shim to get the max allowable. Totally up to you, just saying. Well, I'd get a PAL so scratch that. Actually I'd live in the US so I don't need need one and can be a full on redneck and leave loaded handguns lying around wherever I feel like, shoot in the yard etc etc. Oh wait......

Btw, I've never heard of anyone, or any factory putting a shim under the top hat. They always put them on the rear guide under the spring. I guess it won't hurt but it would bug me b/c I'd be wondering if it's rattling around and adding to the overall noise. Speaking of noise, you can greatly reduce the spring twang, which annoys the hell outta me. I get rid of most of it by making a liner of plastic that fits tightly inside the piston. It's free and not that hard, if interested just let me know and I'll email you the details. Pretty sure I posted it here but not sure where. Plus the info pkg I send has tons of other info you may be interested in. chevota at hotmail if you want it...

Awsome thanks for all the info again