Beeman P3 o-ring replacement

[airgunaut]

My P3, purchased October 2023, recently began shooting not as well and consistently as it used to. I cleaned the barrel (barely any gray/lead on the patches) and lubed the hinges, neither of which improved its condition. It has had somewhere beyond 4000 pellets shot through it.

However, even before I noticed a decline in its shooting, I did see what looked like degraded rubber on the o-ring that seals the breech when the lever is closed. Sometimes it even looks like the o-ring is thinner on one side than the other, as if one side has been worn down slightly or moved over. But its appearance varies, so I think it has shrunk/worn down, allowing the o-ring to move. Photo enclosed below.

I called Air Venturi and waited about 20 minutes before a msg played saying their offices were closed, even though it was 4:30 pm Eastern time (msg says they close at 5 or 5:30 pm).

My questions are these:

1.  What size and type of replacement o-ring should I buy?
2.  What tool do I need to remove this o-ring without harming anything?
3.  Should I smear a tiny bit of silicone grease where the new o-ring will sit, for best sealing? I have some food-grade silicone grease, the kind that scuba divers use.

I really do not want to ship the gun around for this work if I can do it myself.

[OTmachine]

Looks like you need these piston and Breech seals as per:
https://www.tapatalk.com/groups/yellow/piston-seal-o-ring-for-hw40-beeman-p3-t160544.html

568-117 is a 13/16" ID, 1" OD so cross section is 3/32"
568-009 is a 7/32" ID, 11/32" OD so cross section is 1/16" (part #2459)

And then you have your choice of 70 durometer, (soft) or 90 durometer, (harder), and they look to be Buna Nitrile Rubber.  You could use a tooth pick to remove so as not to scar the sealing surfaces.

[Back_Roads]

 I'm just a p17 guy, but there is a lubrication routine that will keep the orings fresh longer. I also use silicone grease on the barrel/breach oring, as it is a high wear item.

[airgunaut]

Thank you both! The o-ring is exposed enough it looks suitable for DIYers. Now all I gotta do is get the right ones. Maybe I'll get both the softer and harder ones.

[airgunaut]

After looking around a bit more, I found a statement that breech o-ring is duro 70 and piston seal is duro 90.

I am hoping I only need to replace the first item but ordered both kinds anyway.

Minimum order size of #009 is 100! Very low cost, at least. Minimum order size of #117 is 50, also inexpensive.

I will have more than a lifetime supply. Wonder if either size is used in the Daisy 880...

[OTmachine]

Glad that you are making headway and glad to help! 

[airgunaut]

Glad that you are making headway and glad to help!

I will have enough to give away if someone needs them! 😀