vent hole placement hern

[buzz36]

Hi got my hern barrel wanted to knoew best placement at the breech
Also need add a brass liner in the vent as this is cast barrel with steel liner
I tried to use the seach feature but i get an error message saying i cant use it tablets have limits i guess

[Frank46]

Could be wrong and someone correct me if I am. the touch hole liner is either made from bronze or copper. There were occasions when the liner hole got too big from firing and then were rebushed. Try a boat yard for either bronze or copper rod to make the liner. Frank

[Double D]

Actually vent liners were made of copper.

Here is what one looked like.



They were screwed in and filed flush.

You want the center of the vent hole to enter the chamber of the barrel far enough from the bottom that when you prick the cartridge the prick is above the base fold of the cartridge and enters the powder  and not the base wad. 

Some cannons had a vent that was angled slightly to the rear. The theory being that if the base wad was too thick the angle would allow the prick  to pierce the wad and go on through to the powder.   

This angle would  also send the ejecta of fuse/primer when fired, rearward instead straight up in the air and fall back on gun/gun crew depending on wind.

[Frank46]

Thanks DD for the correction. Frank