SSP Rifle

[JPSAXNC]

I was working on my SSP rifle making a new poppet for it, I was using some new acetate/Delrin. I use LD's 5 degree toilet plunger design because it makes good power and does not trap debris at the sealing area. After about three shots the velocity dropped. It wasn't unexpected, the new Delrin is soft and caused higher stiction. So I thought I'd try a Peek poppet, of the same design. There's been talk that peek poppets are hard to get a seal, but a Peek toilet plunger seals immediately. And gained 19 fps. due to the lack of stiction.

[JPSAXNC]

When I originally built it I thought the power was much higher. Partly due to my crony giving false readings, and I don't know how, but I calculated the FPE. wrong. The gun makes 9.5 FPE. with 7.9 CP's. Still not too bad.

[subscriber]

You can do a lot with 9.5 FPE, James.  That is a decent power level for a SSP that is not hard to cock.  Getting greedy with SSP power invariably leads to difficult cocking, unless you have a clever mechanism.  Which begs the question, would you be willing to show us more about your design?

[JPSAXNC]

Not hard to close the lever? I wish, 64lbs. and the lever is 19" long! It was one of those things I thought I would try. The stroke is about 8 5/8" the piston diameter is 1.032" with a simple knock open valve. I don't have a way to post pic's.

[subscriber]

If you are using a PC, attaching images is easy:

From the posting window, find the green icon with a + and click it.  The + will turn to a green -
Below that find the "Choose a File" button and click that. Navigate to your image file location and select the fil for attachment.

If you want to attach more than one file to a post, click on (more attachments). Another "Choose File" button will appear below the first one.  You can click more attachments as many times as you need, up to a limit of 10 or 15 images.  (limited by a total combined file size limit of 3.2 Mb)

See screen captures below:

[subscriber]

A peak cockig force of 64 lb is too much for my liking.  This is where a clever linkage such as used on the new Dragonfly Multi-pump pneumatic or Baikal / IZZY MP 46M SSP pistol are worth contemplating for much lower peak cocking force:


https://www.pyramydair.com/product/seneca-dragonfly-mk2-multi-pump-air-rifle?m=5170





Baikal 46M cockcing linkage and piston modelled in CAD.  A lot more detail, here:

https://www.gatewaytoairguns.org/GTA/index.php?topic=153475.0

[subscriber]

I stretched the 46M pistol design for twice the swept volume in an adapted design; shown here:
https://www.gatewaytoairguns.org/GTA/index.php?topic=153749.msg155692324#msg155692324
There are many images at the above link.

I got distracted designing airgun mods, so never made parts for the rifle; but you are welcome to have a copy of the CAD files to see if you find the cocking linkages inspirational.  Otherwise, the images may insure you to do your own.  Certainly, the Dragonfly2 has a more conventional pump layout, so you may prefer that.