Breech plug rubber O-ring and point of impact.

[Chris W.]

Here's a question....How much, if any, difference could it possible make in point of impact if your forget to replace the rubber o-ring in the primer pocket? I have a CVA Optima and I use the rubber O-rings in the primer pocket to eliminate blow back. They work great and I change them out every 12 shots or so, typically. Well, I last went to the range for final sight in about 4 weeks ago and the Optima was shooting great....about 1" high at 100 yards. Jump forward to yesterday morning. I have a decent buck standing broadside at about 80-85 yards. I setup, squeeze off a round and when the smoke clears...he's standing there looking around like he's trying to figure out what that noise was. Completely missed him. Now, I haven't missed an animal with a firearm in I can't remember when, so I was a bit stunned but reloaded as quickly as I could. Unfortunately, not quick enough because he was walking off, rear-end to me by the time I finished. Everything on the shot felt good but things happen and I'm not above admitting that I could flub a shot. Anyway, to make this a story a bit shorter.....I setup a target when we got back to my buddy's place to check things out and the rifle was shooting a full 7-8 inches low at 75 paces. It was then that I also noticed the dirty primer and a lot of blow back on the breech face. Apparently, I'd forgotten to replace the o-ring in the breech plug pocket during after cleaning the rifle last time. Now, I know scopes can go bad or they get bumped around, so I'm making a trip to the range this afternoon to check things out but I was wondering how much, if any, difference anyone has seen in point of impact when a rifle is sighted in using the o-rings and then is shot without one in place to seal the primer pocket? Thoughts?

 

[HC]

I wouldn’t think it would be off that much. Range time should answer your question. Try it both ways.

 

[Chris W.]

I wouldn’t think it would be off that much. Range time should answer your question. Try it both ways.

I'm going to play with it at some point but was wondering if anyone has been there, don't that and what the results were.

 

[michiganmuzzy]

Just low at that distance? No left/right change? I dont think the oring would account for that much deviation. I have forgotten them a couple times and didnt notice very much change in poi.

 

[Chris W.]

Just low at that distance? No left/right change? I dont think the oring would account for that much deviation. I have forgotten them a couple times and didnt notice very much change in poi.

No significant shift left/right. Put two shots down range. Both were less than an inch left of center but 7-8 inches low of point of aim. With only three days left in or muzzy season here in TN, I'm going to hunt the rest with my Optima pistol. I'll sort things out with the rifle at a later date. The o-ring thing was a curiosity.