Diana Airbug/Chaser and Artemis CP2 Barrel Tenon O-rings?

[H95Kidd]

Guys and Gals, WHERE are you folks sourcing replacement o-rings for the barrel tenon on these pistols? I'm told the correct size is metric 0.8mm CS x 8.4mm ID - Buna-N @70 durometer hardness. Does that size sound right? Only place I could find some is "The O-Ring Store" and they want $0.51 EACH with a pretty steep shipping ($9.95) charge. If you bought ten of them plus ship that would be $1.51 each!! That seems like a lot for such a puny o-ring. How about "giving up" your preferred source for these, they can't possibly be that expensive (or can they)? As an aside I looked at a new Artemis CP-2 pistol that a friend just picked up. There were a few spare o-rings included with it, and the barrel tenon o-rings looked to be a "whitish/translucent" color indicating a material OTHER than Buna-N. Maybe polyurethane?? I dunno...  Anyway, thoughts and sourcing info on replacement barrel tenon o-rings welcome!     

[Back_Roads]

 I just get kits, the 8 x 1 should stretch to fit to .8 CS
www.amazon.com/TWCC-Assortment-Pressure-Plumbing-Connections/dp/B09M74NCXV/ref=pd_bxgy_d_sccl_2/142-3687412-9530637?

[mikeyb]

The kits are one option. I like to have both the inch and metric kits available for "surprise" repairs around the shop and home.

For specific applications (not always in the kits) I order bulk o-rings (100-1000pcs) from Amazon WHEN AVAILABLE. My shipping is free and prices usually work out to $0.01-$0.05 per o-ring.

When NOT found on Amazon I go to McMaster-Carr.

https://www.mcmaster.com/products/o-rings/system-of-measurement~metric/width~1-000-mm/id~8-500-mm/

IMPORTANT: I don't know if this size fits your application! It's the closest size to your spec I could see during a quick scan.

same size on Amazon $6.69/30 ? = www.amazon.com/uxcell-30pcs-Nitrile-Butadiene-Rubber/dp/B07FRR2B5P

[H95Kidd]

The kits are one option. I like to have both the inch and metric kits available for "surprise" repairs around the shop and home.

For specific applications (not always in the kits) I order bulk o-rings (100-1000pcs) from Amazon WHEN AVAILABLE. My shipping is free and prices usually work out to $0.01-$0.05 per o-ring.

When NOT found on Amazon I go to McMaster-Carr.

https://www.mcmaster.com/products/o-rings/system-of-measurement~metric/width~1-000-mm/id~8-500-mm/

IMPORTANT: I don't know if this size fits your application! It's the closest size to your spec I could see during a quick scan.

same size on Amazon $6.69/30 ? = www.amazon.com/uxcell-30pcs-Nitrile-Butadiene-Rubber/dp/B07FRR2B5P

[/b]

Thanks for that info Mikey and Backroads! $0.22 each (Amazon Prime) instead of $0.51 looks pretty good. That full kit looks like a no-brainer as well. The cross section (CS) being 1.0mm (instead of 0.8mm) shouldn't be a problem (I hope ). Again, these are for the Diana Airbug pistol or the Chaser pistol/rifle combo barrel tenons. One on each side of the drilled transfer port.

[Spacebus]

It may cost a bit more, but you can get them from forum sponsor Wes Bashforth at https://airgunarcheryfun.ca/

[H95Kidd]

The kits are one option. I like to have both the inch and metric kits available for "surprise" repairs around the shop and home.

For specific applications (not always in the kits) I order bulk o-rings (100-1000pcs) from Amazon WHEN AVAILABLE. My shipping is free and prices usually work out to $0.01-$0.05 per o-ring.

When NOT found on Amazon I go to McMaster-Carr.

https://www.mcmaster.com/products/o-rings/system-of-measurement~metric/width~1-000-mm/id~8-500-mm/

IMPORTANT: I don't know if this size fits your application! It's the closest size to your spec I could see during a quick scan.

same size on Amazon $6.69/30 ? = www.amazon.com/uxcell-30pcs-Nitrile-Butadiene-Rubber/dp/B07FRR2B5P

Well darn, I got ahead of myself and ordered some 1.0mmCS X 8.5mmID orings from Mcmaster-Carr, they had some "super resilient" (their discriptor ) in 70-75 Durometer, and in Viton no less. I figured might as well GO for it right? MikeyB did warn me he was not sure about fitting the application, but I figured what the heck, it SHOULD fit, right?  WRONG----Unfortunately, when installed, they are just a bit too large to start into the receiver bore on the Diana/Artemis receivers. Hard to believe just a 0.2mm increase in CS and 0.1mmID would "stack" and prevent entry into the receiver bore. The CORRECT size o-ring is indeed 0.8mmCS X 8.4mmID. What I am eventually going to do is calculate the correct barrel tenon GROOVE dimensions for the McMaster-Carr 1mm x 8.5mm o-rings, and machine (slightly deepen, perhaps widen them as well, it shouldn't take much, we'll see) the barrel grooves accordingly (have lathe, will travel ). The 1 x 8.5mm size o-ring is WAY more common, much cheaper, and easier to source as well. The "O-ring Store" wants $0.51 APIECE + $9.95 shipping for the correct 0.8mm x 8.4mm size. Must be gold plated or something, I dunno... 

While I was fooling around with this stuff, and examining things, I noted the barrel crown and also the chamber entry of my Chaser pistol barrel kinda sucked, p-ss poor machining to say the least. The pellets had a distinct "catch/hesitation" while pushing the bolt home to fully chamber them. So into the lathe the barrel went for "cleanup". Unfortunately (or maybe fortunately?), I had to modify the front sight to get the barrel into my little South Bend lathe. "Modify" means cut the blade off and then machine the base completely cyndrilical. It actually looks good, and I didn't really need the sight blade on there anyway (scopes/red dots only for me, eyes are shot for irons). I'll post a pic later. Cleaned up the crown and the chamber entry as well, pellets feed much nicer/smoother now. Hopefully the accuracy is improved as well, probably do some accuracy testing in the AM. By the way, I'm running the moderator (normally used on the rifle barrel) on the pistol. Nice and quiet!

[Spacebus]

You can just slide the front sight off, but the barrel does look weird without it.

[H95Kidd]

You can just slide the front sight off, but the barrel does look weird without it.

DJ--That was my thought as well, that was 2nd reason I just machined it round. It looks like it actually belongs there (sans blade) now, like it was a "factory" deal. I still have to post a pic, I'll get to it soon. Powder burner matches this weekend, loading up my gear for today's match momentarily ("Hi-Power" Service Rifle), Sunday is .22RF benchrest. The .22RF BR match is a whole lot more relaxing than the SR match. SR is a lot of work, getting harder to get into prone and sitting positions at my age. Also, it's a little "brisk" out and wet out there (from 2-3" of previous rain this past week) this AM here in NE Ohio, I'll be wearing my LongJohns and Muck boots for sure! Sunday's weather is supposed to be much nicer and warmer.

[Spacebus]

You can just slide the front sight off, but the barrel does look weird without it.

DJ--That was my thought as well, that was 2nd reason I just machined it round. It looks like it actually belongs there (sans blade) now, like it was a "factory" deal. I still have to post a pic, I'll get to it soon. Powder burner matches this weekend, loading up my gear for today's match momentarily ("Hi-Power" Service Rifle), Sunday is .22RF benchrest. The .22RF BR match is a whole lot more relaxing than the SR match. SR is a lot of work, getting harder to get into prone and sitting positions at my age. Also, it's a little "brisk" out and wet out there (from 2-3" of previous rain this past week) this AM here in NE Ohio, I'll be wearing my LongJohns and Muck boots for sure! Sunday's weather is supposed to be much nicer and warmer.

Our local 22rf benchrest season is starting soon. I don't have the budget for expensive gear so I just turn up and have fun. The old guys that show up have four figure rests, wind flags, 50x scopes, etc.

[H95Kidd]

You can just slide the front sight off, but the barrel does look weird without it.

DJ--That was my thought as well, that was 2nd reason I just machined it round. It looks like it actually belongs there (sans blade) now, like it was a "factory" deal. I still have to post a pic, I'll get to it soon. Powder burner matches this weekend, loading up my gear for today's match momentarily ("Hi-Power" Service Rifle), Sunday is .22RF benchrest. The .22RF BR match is a whole lot more relaxing than the SR match. SR is a lot of work, getting harder to get into prone and sitting positions at my age. Also, it's a little "brisk" out and wet out there (from 2-3" of previous rain this past week) this AM here in NE Ohio, I'll be wearing my LongJohns and Muck boots for sure! Sunday's weather is supposed to be much nicer and warmer.

Our local 22rf benchrest season is starting soon. I don't have the budget for expensive gear so I just turn up and have fun. The old guys that show up have four figure rests, wind flags, 50x scopes, etc.

DJ--Just back from the Service Rifle match, made a rookie mistake that cost me the match win. Took 2nd, but lost by 1 point (me 485, winner 486 out of a possible 500). Got on the trigger too hard on the take-up before the "wall" (2-stage trigger) and pulled right though the 2nd stage during Sitting Rapid Fire, resulting in a "7" on the target. THAT shot cost me the match, that hurts when you make a rookie mistake like that! My excuse is fingers were COLD, and I'm going with that.... . Hope to do better in tomorrows .22 RF benchrest match.

Anyway, pics attached of my turned-down Chaser front sight base. The blade is GONE! I like it  

[Spacebus]

If you're using the barrel band with a dovetail on the top, you can put a set screw through the threaded hole to prevent the band from rotating

[H95Kidd]

If you're using the barrel band with a dovetail on the top, you can put a set screw through the threaded hole to prevent the band from rotating

DJ---Yeah, that band does have the dovetail, and is a "spare" that I picked up from Wes. Also the Diana moderator as well. In that regard: Did you mean, perhaps, another setscrew in that band to help keep the BARREL itself from trying to rotate? As in while installing/tightening or removing the suppressor? That makes sense to me, as I would normally just grasp the sight blade with my "other" hand/fingers as an aid for this operation. The idea WAS (that is, before I cut/machined the blade OFF) to provide some opposing resistance to this operation, and take as much load off the receiver/barrel retention setscrews as possible. Otherwise, I don't think that band is going anywhere, as it is spanning/clamping both the barrel AND the larger diameter CO2 "tube" together. The clamping force of that band alone (around the barrel OD that is), is probably enough to provide the desired rotational resistance while removing/installing the suppressor. Another setscrew, though, certainly wouldn't hurt anything .

[Spacebus]

If you're using the barrel band with a dovetail on the top, you can put a set screw through the threaded hole to prevent the band from rotating

DJ---Yeah, that band does have the dovetail, and is a "spare" that I picked up from Wes. Also the Diana moderator as well. In that regard: Did you mean, perhaps, another setscrew in that band to help keep the BARREL itself from trying to rotate? As in while installing/tightening or removing the suppressor? That makes sense to me, as I would normally just grasp the sight blade with my "other" hand/fingers as an aid for this operation. The idea WAS (that is, before I cut/machined the blade OFF) to provide some opposing resistance to this operation, and take as much load off the receiver/barrel retention setscrews as possible. Otherwise, I don't think that band is going anywhere, as it is spanning/clamping both the barrel AND the larger diameter CO2 "tube" together. The clamping force of that band alone (around the barrel OD that is), is probably enough to provide the desired rotational resistance while removing/installing the suppressor. Another setscrew, though, certainly wouldn't hurt anything .

Maybe the pistol barrel is short enough to not matter, but on my Stormrider it's really easy to rotate that band when it's out near the end of the barrel, which of course causes the barrel to point off center. I solved this with a set screw in the threaded hole.

I also find that the front sight blade can easily shift/rotate a few degrees if you use it as an anchor point. This probably doesn't matter since you don't have the leverage from the blade anymore.

You would be shocked at how little that band does. If assembled correctly you should be able to pull the barrel from the receiver without loosening the barrel band. Even on my Stormrider I can pull the barrel without loosening either of the the two barrel bands, assuming I didn't add an extra set screw.

[BanjomanMI76]

My source for Chaser parts is in the UK. They have a lot of the appropriate seals and O-Rings seemingly not available here in the USA.
https://spares.bagnallandkirkwood.co.uk/

[Baco]

just calculate how much rubber is in the original oring get a size a bit smaller but same rubber volume stretch it over and gg

[H95Kidd]

I just get kits, the 8 x 1 should stretch to fit to .8 CS
www.amazon.com/TWCC-Assortment-Pressure-Plumbing-Connections/dp/B09M74NCXV/ref=pd_bxgy_d_sccl_2/142-3687412-9530637?

Backroads and Baco---thanks for the suggestion. Before I go modifying the existing barrel tenon grooves (using the lathe) I better pick up a few of these (the 8x1) and at least TRY them on for fit. Maybe they will fit/work OK. I don't know why SnowPeak picked that truly (&#^((&^* size 0f 0.8mm CS x 8.4mm ID for the Diana/Artemis barrels. They are just NOT at all common.  At least not from o-ring supply houses, that's for darn sure. I did find a place that sells them, but they want $0.51 EACH plus shipping! Yikes!

[H95Kidd]

If you're using the barrel band with a dovetail on the top, you can put a set screw through the threaded hole to prevent the band from rotating

DJ---Yeah, that band does have the dovetail, and is a "spare" that I picked up from Wes. Also the Diana moderator as well. In that regard: Did you mean, perhaps, another setscrew in that band to help keep the BARREL itself from trying to rotate? As in while installing/tightening or removing the suppressor? That makes sense to me, as I would normally just grasp the sight blade with my "other" hand/fingers as an aid for this operation. The idea WAS (that is, before I cut/machined the blade OFF) to provide some opposing resistance to this operation, and take as much load off the receiver/barrel retention setscrews as possible. Otherwise, I don't think that band is going anywhere, as it is spanning/clamping both the barrel AND the larger diameter CO2 "tube" together. The clamping force of that band alone (around the barrel OD that is), is probably enough to provide the desired rotational resistance while removing/installing the suppressor. Another setscrew, though, certainly wouldn't hurt anything .

Maybe the pistol barrel is short enough to not matter, but on my Stormrider it's really easy to rotate that band when it's out near the end of the barrel, which of course causes the barrel to point off center. I solved this with a set screw in the threaded hole.

I also find that the front sight blade can easily shift/rotate a few degrees if you use it as an anchor point. This probably doesn't matter since you don't have the leverage from the blade anymore.

You would be shocked at how little that band does. If assembled correctly you should be able to pull the barrel from the receiver without loosening the barrel band. Even on my Stormrider I can pull the barrel without loosening either of the the two barrel bands, assuming I didn't add an extra set screw.

[/b]

Wow, that is crazy! I would have thought that the band would solidly tie the barrel to the larger airtube. I remember seeing a DOUBLE setscrew band, the double where the clamping force was applied. I think this (the double screw) was used on "older" Stormriders, and now only the SINGLE clamp screw version is available. The things you learn/find out here on GTA!