O-Ring sizes for Shocktech Bomb 2 3-way

[gogi19]

Hi all,

I just bought a project Prostock off a member and am making my way through the rebuild. It came with an ST Bomb 2 but a few of the shaft orings are knicked and leaking so I wanted to buy some replacements.

Everything I can find via Google says they're "proprietary" but it seems like they mic out to be metric 1.5mm ID x 4.5mm OD x 1.5 mm CS o-rings. I just wanted to verify size and material before putting in an O-ring store order. Thanks!

[Alexndl]

From what I understand, they are not a standard size and no exact replacement have been identified. They are silicone and the duro is also not common.

Shocktech sell the shaft with the oring

https://shocktechusa.com/products/bomb-ii-shaft-w-o-rings

There is also a post with a procedure to drill the inside of a 003 oring to make it work with a bomb 3 way. Probably your best bet if you dont want to buy the shocktech parts.

[gogi19]

Man, that's frustrating. I sent ST customer support and email to see if they'll sell me some since it seems no retailers have them in stock. O ring store has some 70 duro silicone rings that fit the dimensions that I may try out. I'd hate to have to junk a part just because of some o-rings.

The o-rings that are on there now are white in color which I guess means they're replacements for the original red ones ? Guess that explains why they failed if so. I did see the post about boring out the 003s. I may give that a shot in the interim, thanks

[superman]

you don't want to buy those. I know ST went looking for replacements not that long ago and they break when putting them on.
Also I am a shocktech dealer and have the stems and orings in stock.

[superman]

They are 003, but they are different material and durometer. you can sometimes get away with 003 d70 but it may be a bit on the sticky side depending how tight the tolerance is. If you need the correct oring, i can sell you the shaft with the 3 orings on it as pictured above. My shipping is typically cheaper and faster than shocktechs. Just a FYI.

[gogi19]

Thanks again! The seller also threw in an ID 3 way so I'll likely just switch to that one given the bad news on the o ring front. If I do end up buying the part for it it'll be from you!

[Toestr]

Have you tried 003 50?

[Ecapnation]

https://www.mcmaster.com/product/1173N003

I've been using these for a few years now

[gogi19]

Thanks for the recommendation! I'll order a few packs once my McMaster Carr shopping list gets long enough

[Trbo323]

Man, one of you guys who has a lot of experience with different 3 ways should out together a sticky thread of o ring sizes for different 3 ways. It seems to be the question that comes up the most and there's no one list to reference

Sent from my motorola edge 5G UW (2021) using Tapatalk

[superman]

most of which are 003's.
New dye 3 way is proprietary. old one was a funky size.
Inception is 3mmx1mm.
That covers like 90% of 3 ways out there being used.

[gogi19]

As someone pretty new to autocockers, I agree haha. It feels like some manus (ID not included) willfully avoid publishing O-ring and screw sizes.

There's a couple good lists out there ( I found one on Docfire's site for empire/ID cockers) that list all the O-rings for a specific model of marker. It'd be awesome to have a reference list similar to that in a wiki or something but to BW's point, I guess a lot of it would be redundant.

[Ecapnation]

What Superman said ..

Aside from like three oddballs everything is 003

[Psycho91]

Sorry to thread jack but this made me remember years ago ans carried poly orings for wgp 3 ways (was told they are a tad smoother) but they no longer have them it seems, is anyone using poly orings in their 3 ways or just stick with buna

[SR_matt]

Can confirm that the random 003 silicone rings on amazon are very hit and miss. I got some when rebuilding a rat valve and the first ones I got were impossible to get into the valve without snapping.

Probably easiest (read: less amount of flaming your head against a wall when the ones you keep ordering dont work) to just get them from Shocktech or one of the dealers like bearded works. may not be as cheap per ring but you know they will be right. Its not like you gave to change them out regularly so long term cost savings is basically null.

[SR_matt]

I mean just get the ST ones and you wont have to touch it for years. It seems that the issue is more so that the rings are not commonly used even if they are a common size and/or the quality of that size is just low from a lot of manufacturers.

[superman]

Not only that ordering one from Shocktech or shocktech dealer gets a new shaft with the broach in the end to make the adjustment easier.

[SR_matt]

apparently I somehow missed that the new shafts have the Allen key hole in the end... to be fair though I havent been able go actually put this build together yet so I guess thats not too bad of a miss.