- Joined
- Jan 19, 2023
- Messages
- 152
- Reaction score
- 214
I have seen threads where shooters where using O rings in there primer pockets.What size?where do you get them?How long do they last.
o rings?
- Thread starter primer mark
- Start date
Help Support Modern Muzzleloading Forum:
- Joined
- Jan 4, 2022
- Messages
- 3,054
- Reaction score
- 6,854
McMaster Carr 1mmx4.5mm o-rings
- Joined
- Jan 19, 2023
- Messages
- 152
- Reaction score
- 214
Wow ,that is great.thanks.I just ordered some.
- Joined
- Jul 18, 2015
- Messages
- 389
- Reaction score
- 244
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.
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.
- Joined
- Aug 7, 2023
- Messages
- 396
- Reaction score
- 745
Had mixed results with the o-rings. They do help though if you've got bad blowback issue's. Really wish someone would make a good full replacement plug and bushing. I have to keep resetting the headspace. Lasts a few shots then I start getting blowback again even with lock tight. Might be going back to the o-rings.
