QB78 Bolt Probe O-ring Size?

[iconoclast]

One of the QB78 tune guides states a 002 O-ring size for the .177 bolt probe.
However, the 002 O-ring size is approximately 1mm ID x 3.5mm OD
And the O-ring off of my bolt probe is approximately 3mm ID x 5mm OD.
These dimensions do not fit any of the standard American O-ring sizes that I've seen.
Can someone help me out on the correct size?
Thanks.

[mikeiniowa]

1mm X 3mm is the factory size, have to convert that to english measurements......slightly over size won't hurt, may have to sand it down slightly to get perfect fit.....

[iconoclast]

1mm X 3mm is what was designated in the QB78 tune guide.
So, I bought a 1mm x 3mm O-ring and it doesn't even come close to fitting.
3mm x 5mm is the size of O-ring that came off the bolt probe.
I've looked at several American Standard O-ring charts that give both inch and metric dimensions and nothing I see in the charts come close to 3mm x 5mm.
Actually, I have a QB78 Deluxe.
Could the Deluxe have a different bolt probe O-ring than the QB78?

[mikeiniowa]

no the bolts are the same, sure you have a .177?

[iconoclast]

Yes, I'm shooting .177 pellets and my breech says 4.5mm.
------
However, I did some researching on the internet and found my answer.
The o-ring is a metric size.
The size designation = M1X3
M says it's metric
1 says the cross section is 1mm
3 says the inner diameter is 3mm
So, the outer diameter is 3 + 1 + 1 = 5mm
This is the exact size of the factory oring.
This is what I need.
I even found some Buna 70 this size on ebay.

[mikeiniowa]

you got it......want some? I can send a few if you want, won't be to you until monday but....just send me your address.....