Home Forums Hunting & Shooting Muzzleloaders Ignition Issues

the flash from the cap goes through the nipple . then it turns 90 deg and runs through the drum bolster neck into the barrel . then it must turn 90 deg into the main charge ..

See the bolsters on CVA rifles do not thread into the bore . They thread into the breech .
The face of the breech is counter bored . So what you get is a modified improved breech design that utilizes a drum type bolster vs. a snail type breech .
Here are the three different drum bolsters CVA has used through the years



On the right is an original type drum bolster of the type originally used to convert flintlock to cap lock as well as being common on early original rifles and is still commonly seen today ..
Note that this and the short CVA bolster , screw through the barrel wall . They both set just in front of the breech face and thus Ignite the powder charge from side of the powder column .
Note the medium and long necked bolsters have a hole in the side of the neck . . That hole lines up with a hole in the breech face which then travels to the bore of the rifle and thus the main charge which then gets ignited from the back of the powder column and centered .
So what you end up with is a design like this breech plug from a Pedersoli blue ridge rifle IE the bolsters thread into the plug like the flintlock liner threads into this breech plug


breech plug face


That hole in the neck of these CVA bolsters , sometimes are nothing more then a very small or only a slit . OR the hole is to small and becomes fouled to the point it restricts the ability of a small amount of powder to enter the neck of the bolster .
So as I said before . Instead of the flash simply turning right 90 deg �Under the nipple �
And igniting powder it must travel down the nick and turn left 90 degs and exit the neck of the bolster and ignite the main charge .
Now add in a powder like T7 or Pyro , which has a higher ignition temp .
The farther away from the cap the flash must travel combined with the more turns it must make , the less heat it carries. Not to mention if your flash channel is restricted by fouling , that restriction will also result in less heat getting to your main charge .

So for the best possible ignition , you need to have a powder that will ignite at a lower temperature OR /and , a clear flash channel that will allow a small amount of powder to end up under the nipple to help boost the flash from the #11 cap , to the main charge .
This is why a previous poster suggested taking out the clean out screw and checking the flash channel . As you can see from the photos of the bolsters , the flash channel is large . it�s the same diameter as the ID of the threads on the clean out screw .
I would bet that for those here who have posted that they have good luck with T7 or Pyro , its because they that small amount of powder , getting into the flash channel of the drum bolster .