How to make those CB's even quieter

[Dolomite_supafly]

So I recently bought some CB's for use in my suppressor. Well I was pretty upset when I pulled the trigger on the first one. The noise from the chamber was so loud it made hearing the shot impossible and even caused my ears to ring a bit. I tried those CB's in every 22 I own and found the same results about 1/2 the time. And they were even louder at the chamber than at the muzzle on rifles without the suppressor. For me this was rather upsetting because subsonic 22lr is quieter with my suppressor. than the CB's when they do not seal

So I got to thinking about how I could prevent this.

I knew I had to seal the case to the chamber but how.

Well after some thought I grabbed the only thing I had handly, some black electrical tape. I used some scissors and cut a piece off the end of the roll that is about 1/8" wide. The tape is wide enough to wrap perfectly around the casing without overlapping. And it is just thick enough to seal the case to the chamber without impeding extraction after firing it.

The first shot was extremely quiet but that wasn't the test. The test came over the next 50 rounds when ALL of them sealed completely. And because they are sealed completely they are even quiet in rifles without a suppressor. And with a suppressor the firing pin is louder.

Dolomite

[MacGyver]

Interesting. I'm going to be extruding my own brass before I'm done.

[enfield]

How about posting a picture of a tape-wrapped round so we can see what you're doing?

[Dolomite_supafly]

And as I said the width of the tape is perfect. It goes all the way around without overlapping or coming up short. It seals it off very well.

Dolomite

Edited June 21, 2012 by Dolomite_supafly

[enfield]

Gotcha - thanks!

[peejman]

So the bolt isn't holding the case rim tight enough against the breech face for it to seal? Is there an obvious gas escape (other than the noise)? That may be normal for a .22, it just seems a little odd.

How much does the size of the brass vary?

[Dolomite_supafly]

So the bolt isn't holding the case rim tight enough against the breech face for it to seal? Is there an obvious gas escape (other than the noise)? That may be normal for a .22, it just seems a little odd.

How much does the size of the brass vary?

Most 22 bullets vary so much that most guns have a very loose headspace to make the reliable with all of them. Add that to a bullet that does not seal well to the chamber and you get blowby.

There is a fair amount of blowby from the port. and in a rifle without a suppressor it is even louder that the report at the muzzle.

Under "normal" circumstances the pressure of firing swells the case mouth and seals the gases in but the CB doesn't have enough pressure to do this.

Dolomite

[Ramjo]

Interesting...

[peejman]

Interesting...

Yes, quite.