sealing 209 primer pockets

[jbs27572]

Does anyone have a link for heat resistant o-rings to seal 209 primer pockets on break open CVAs? I found an old 2016 post with a link but I don't know if there is another better option in 2023. Those o-rings were rated at 250 deg F.

 

[michiganmuzzy]

Does anyone have a link for heat resistant o-rings to seal 209 primer pockets on break open CVAs? I found an old 2016 post with a link but I don't know if there is another better option in 2023. Those o-rings were rated at 250 deg F.

This is the link to the correct oring. 9262k611

https://www.mcmaster.com/product/9262K611

 

[michiganmuzzy]

Same dimensions but Viton. Handles more heat, to 400*f instead of the 250*f buna-n, and is slightly harder so it may last longer, but it isnt as resistant to as many chemicals, which may not make any difference. 1295n117

https://www.mcmaster.com/product/1295N117

 

[jbs27572]

Awesome, thank you. I ordered some.

 

[michiganmuzzy]

I was thinking about trying these…
McMaster-Carr
Same buna-n but in a square profile, just to see if they last any longer.

 

[jbs27572]

How would a square shape help it last longer and would they even fit in the round primer pocket?

 

[HC]

 

[michiganmuzzy]

The oring itself is still round, it has a square cross section. It would make more surface contact at the sides and bottom of the primer pocket and against the face of the primer. The round ones last 20-40 shots before the are wornout and i replace them. Im just thinking they might get 50-60 shots instead. Just an experiment.

 

[jbs27572]

Oh, LOL, I'm an idiot. Of course; that makes way more sense.

 

[billyboy*]

The oring itself is still round, it has a square cross section. It would make more surface contact at the sides and bottom of the primer pocket and against the face of the primer. The round ones last 20-40 shots before the are wornout and i replace them. Im just thinking they might get 50-60 shots instead. Just an experiment.
View attachment 32415View attachment 32416

I Like the idea of more surface area. Curious if they would be Harder to Compress?

 

[Swamp]

Following

 

[michiganmuzzy]

It may not be worth it, they are more than $1 each, once shipping and tax is added.

 

[jbs27572]

Yeah but you still get a pack of 25 and 25 bucks isn't going to break the bank. Twenty five o-rings would last years for me too so I would probably still consider it if he found they were better.

 

[MuleDad]

Following

me too(no hashtag)

 

[Travis299]

I have used this O-Ring in my Accuras for several years to stop blowback which can foul the firing pin assembly. McMaster-Carr

Fired & unfired primer using O-Ring.

CVA BP Rifle primer blowback problem.
IMO, when the primer is fired there is a lot of resistance or back pressure on the primer ignited hot gas caused by the small size of the fire/flame hole, .028” to .033”. This resistance/pressure means that it is imperative that the primer is sealed into the primer pocket to prevent the hot gas from escaping back around the primer and exciting to the rear, blowback. This blowback can foul the firing pin assembly in addition to the fact that it is wasted hot gas that is intended to ignite the powder charge. The sealing of the primer is also made more difficult because all primers are NOT the same length. If the fired primer has black carbon/soot on the sides of the primer than this is an indication of the blowback problem. I have found, from recommendations on BP forums, that using the rubber O-Ring in the primer pocket that the blowback problem is solved for whichever primer I am using. The O-Ring will last for 10/20 shots and you get 100 O-Rings for about $5. This is the site for the O-Ring.

McMaster-Carr

This O-Ring can be seated into the base of the primer pocket using a primer to push the O-Ring in. When loading the primer into the BP rifle, point the open action down while inserting the primer and then close the action with a firm snap. Also check that the firing pin bushing is flush with the face of the receiver with no indentation or protrusion. This will insure that the action will open/close without any problems.

 

[jd24.5.48]

I was using the Winchester W209 primers and didn't have much blowback. I switched to the Cci 209M primers and I'm getting a good bit of blowback now. Accura V2 Lr. I'm going to get some o rings and see what happens. I'm also going to get the SSK breech plug with the vent liner and hopefully that will solve the problem.

 

[MrTom]

Using the W209 Winchester primers my Optima pistol and Accura V2 shoot clean without the rings, so those are the only primers I use in those guns. My Kodiak .45 needs a ring for any primer.

I'm curious how tough the rings are should my Patriot need one using smokeless powder? I get about 20-25 shots out of a ring in the Kodiak with a moderate powder charge. The Woodman is also a .45 but will only see smokeless powder.

 

[michiganmuzzy]

Using the W209 Winchester primers my Optima pistol and Accura V2 shoot clean without the rings, so those are the only primers I use in those guns. My Kodiak .45 needs a ring for any primer.

I'm curious how tough the rings are should my Patriot need one using smokeless powder? I get about 20-25 shots out of a ring in the Kodiak with a moderate powder charge. The Woodman is also a .45 but will only see smokeless powder.

Thats what i hope to find out with the square profile o-rings. If they last longer or seal better than the round ones. I may try some hot loads and might get to try them with smokeless.

 

[MeatMachine]

I was thinking about trying these…
McMaster-Carr
Same buna-n but in a square profile, just to see if they last any longer.
View attachment 32411

Don’t forget that the oring will need to compress to .010 or less and the round tube style would do it much easier. I’m just thinking you’ll probably have to slam the action pretty hard to get it to work.

 

[michiganmuzzy]

I Like the idea of more surface area. Curious if they would be Harder to Compress?

So ive been tinkering with some breech plugs and the square profile o-rings. Thanks billyboy*, for sending me some. In my CVAs the sq o-rings compress just fine. In my Omega… not ‘no’ but HELL NO! So I did a bit of mod work to a few breech plugs that I’ll start a new thread on, soon.