Question about Barrel Breech End O-Ring used on the PP-800 / Artemis, Bandit, Snowpeak pistols

[ThomasT]

Hello everyone,

Does any body know what material is used to make the Barrel Breech End O-Ring used on the PP-800 / Artemis, Bandit, Snowpeak pistols? Wes told me that he did not know but it is not Buna-N 70 or 90.

This is the O-Ring that fits in the Breech End of the Barrel that the Probe pushes the pellet into the Barrel. The color is NOT black but more of a Brown-ish color. See photo of one out of my Pistol.

The closest that I can find on ORings and More is:
FKM Heat Resistant O-rings

5.5mm ID x 8.5mm OD x 1.5mm C/S
Also known as JIS S6
75 Durometer Rubber FKM O-rings
A general purpose FKM (Fluorocarbon Elastomer) compound suitable for applications requiring resistance to high temperatures and compression set. Outstanding resistance to blended aromatic fuels and straight aromatics as well as halogenated hydrocarbons. Good resistance to strong acids and steam. Temperature range -20° to 400°F (-29° to 204°C).
Color Brown

Thanks for your help,
ThomasT

 

[Motorhead]

While I never researched the factory material or size ... having had a difficult time in getting the breech to seal up and not squirt out air during a shot I came up with mod you might find of interest ?
Taking the shoulder on barrel at the breech end a tad further back, installed an HW breech seal in lieu of the o-ring. It has been there now near 6-7 years and has worked great !!

** pistol has been a .177, .20 and as shown .25 all had been retrofitted and actually used the same seal over & over.

 

[nervoustrig]

Thomas, you are on the right track. SPA is in the habit of using FKM (Viton), but be advised it offers no particular advantage for a breech seal. Feel free to go with a Buna-N or polyurethane replacement.

 

[ThomasT]

While I never researched the factory material or size ... having had a difficult time in getting the breech to seal up and not squirt out air during a shot I came up with mod you might find of interest ?
Taking the shoulder on barrel at the breech end a tad further back, installed an HW breech seal in lieu of the o-ring. It has been there now near 6-7 years and has worked great !!

** pistol has been a .177, .20 and as shown .25 all had been retrofitted and actually used the same seal over & over.

View attachment 513111

Hello @Motorhead

That is a very nice looking modification. However that will not work on the Bandit/Stormrider style of Breech O-Ring assembly, see attached photo.

ThomasT

 

[ThomasT]

Thomas, you are on the right track. SPA is in the habit of using FKM (Viton), but be advised it offers no particular advantage for a breech seal. Feel free to go with a Buna-N or polyurethane replacement.

Hello @nervoustrig

Thank you. I believe I will go ahead and place an order for both and see if one works better than the other.

ThomasT

 

[Motorhead]

Hello @Motorhead

That is a very nice looking modification. However that will not work on the Bandit/Stormrider style of Breech O-Ring assembly, see attached photo.

ThomasT
View attachment 513130

This is true ... my response was specific to the swing gate snowpeak pistol. Sorry if misleading to others.

 

[ThomasT]

This is true ... my response was specific to the swing gate snowpeak pistol. Sorry if misleading to others.

Hello @Motorhead

No problem, your information might help those that have that model of the Pistol.

ThomasT

 

[ThomasT]

Hello everyone,

OK I just placed an order for 50 each for both "types" of material. These will be for the .22 caliber Pistol and the O-Ring size is 1.5mm CS ( cross section ) x 5.5mm I.D. x 8.5mm O.D.

After they come in, I will do a short test on both and give a report here.

Thanks for the help,
ThomasT