A word here concerning the last post .
Drum bolsters SHOULD NOT MOVE.
If they do its because they have not seated or shouldered properly . They must be set tight and aligned properly at that position where they seal .
If the bolster doesn’t seal , fouling gets in the threaded . .
If you bolster is coming lose and must be constantly tightened , its telling you something is wrong and needs to be replace . This doesn’t mater if it’s a VA or a drum bolster on a custom gun.
Now another thing to consider here . CVA no longer uses a short necked drum bolster . They use a through bolster . This reaches not only through the barrel wall but completely across the bore .
The breech plug itself is of an improved breech design . As such it is center drilled . The neck of the bolster goes all the way across this chamber and faces against the opposite wall . In a couple cases I have found where they go all the way through the plug and face to the of side of the inner barrel wall .
The bolster is also soft steal . As such over tightening will stretch the threads . Your thinking your tightening , but what you really doing is twisting the neck and will eventually weaken it .
So be very carful with your adjustments .
If you bolster is continually coming lose , take it to a competent gunsmith and have it fixed OR learn how to fix it correctly yourself .
The life you save wont be your own but it could very well be the person standing on the bolster side of your rifle .
Now as to your cap problem .
There are a couple things to consider .
1) you could have a weak main spring . This is common with CVA .
2) your hammer may not be aligning properly . A large % of the time this is very common with The smaller CVA locks . But I find that its do to the softness and weakness in the hammer .
A simple , easy and safe thing to fix . If this is a problem you find out by looking at the cap and seeing how the hammer is contacting the cap . Or you can look up into the hammer cup and see the wear mark .
it’s a common miss conception that a hammer must contact the full face of the nipple .
It is preferable that this happen , but it isn’t necessary . All the hammer has to do is strike a small area to set the cap off
3) is an issue that many folks don’t know or misunderstand. See you can use a #11 cap on a #10 nipple but you will have a problem if you try and use a #10 cap on a #11 nipple .
Recently I have found that the standardization amount the cap companies , especially CCI and Remington with their caps being alittle undersize . This relates directly to #4
4) think on this CVA , Pedersoli , investment arms , traditions , are all made in Europe. CVA and traditions being made by the same parent company called Jukar .
Now they all use metric threads . But past that the nipples , bolster threads , breech plugs and such are all milled to metric standards .
As such you can run into an issue with caps not fitting all the way down on the nipples .
If this is the case you can easily fix it by taking a light diamond file and lightly touching up around the outside diameter of the nipple . This will often let the cap set all the way down .
The other thing you can do is what others have said . When you place the cap , push it down hard with your thumb .
Anyway that’s some things I have found in my years as a gunsmiths that you might want to consider