I've been ordering O-rings for my P35s almost from day one. They come with a set and tools but I wondered about the quality and decided I needed to buy some. I have three P35s and one has an aftermarket plenum (my 25 caliber) which has been a bit of a bear to eliminate a slow leak from. But I think I have it now. But that meant I had to try some non-OEM O-rings too. So my assortment will not be the same as yours in all probability. I also have a 177, 22, and 25 and if you do not, you won't need all the O-rings for inside the barrel. Some I've never replaced, like the two on the outside of the regulator, but I went ahead and bought some just in case. I marked with an asterisk some I don't think you will probably need. The ones I've replaced the most have been the big one on the outside of the big nut on the gauge end of the airtube and the little O-ring on the inside of that nut that forms the one way valve. So some you definitely need in my opinion and some you probably do not. But I don't think I've change a single one on my P35-22. It shoots so well I do not want to mess with the regulator and if you do not, it will greatly reduce the need for O-rings in my experience.
But I wanted to get all my O-rings organized so they are easier to find than all the little baggies of O-rings I've accumulated with some of them being mis-orders. You will also note in the pictures that I put the OD, ID, and thickness on the label for each O-ring compartment. I think that is the way O-rings should always be referred to. But in catalogs and on baggies it seems to be extremely common to just refer to the ID and thickness. It is 100% true that those two parameters give you the OD but it is EXTREMELY easier to measure the OD that is is the ID in my experience and when you get confused placing an order you end up with somewhat useless O-rings and have to place another order. So I like to have all three parameters handy. I bought the little organizer I used from Amazon and the labels are some 1.25 inch sticky labels I bought to go insider scope occular lens covers for dope on hold over. I had plenty so I used some to label the box. I'm hoping you can read the labels to get the sizes. Some are on diagrams for the guns but not all are (like the ones in and around the regulator). There are also some C-clips for the cocking mechanism and a couple grub screws in this little organizer that also fit my P35s. I do not know for sure all the O-rings are the same in the Bullshark but I am confident at least most of them will be.
But I wanted to get all my O-rings organized so they are easier to find than all the little baggies of O-rings I've accumulated with some of them being mis-orders. You will also note in the pictures that I put the OD, ID, and thickness on the label for each O-ring compartment. I think that is the way O-rings should always be referred to. But in catalogs and on baggies it seems to be extremely common to just refer to the ID and thickness. It is 100% true that those two parameters give you the OD but it is EXTREMELY easier to measure the OD that is is the ID in my experience and when you get confused placing an order you end up with somewhat useless O-rings and have to place another order. So I like to have all three parameters handy. I bought the little organizer I used from Amazon and the labels are some 1.25 inch sticky labels I bought to go insider scope occular lens covers for dope on hold over. I had plenty so I used some to label the box. I'm hoping you can read the labels to get the sizes. Some are on diagrams for the guns but not all are (like the ones in and around the regulator). There are also some C-clips for the cocking mechanism and a couple grub screws in this little organizer that also fit my P35s. I do not know for sure all the O-rings are the same in the Bullshark but I am confident at least most of them will be.
