« previous next »
Pages: [1]   Go Down

Author Topic: Vent diameter to bore ratio  (Read 393 times)

0 Members and 1 Guest are viewing this topic.

Offline SMFanvilhead

  • Trade Count: (0)
  • Posts: 1
Vent diameter to bore ratio
« on: August 03, 2012, 02:58:48 AM »
Newby Alert! I am in the process of making a "parrott" style BP cannon with a .75 dia. bore. What size- dia. should the vent be? If making a threaded copper vent tube, what dia. should it be? Should the threads be UNF or UNC? I did make a search, but did not see any info for this.
Thanks for replies.
Logged

Offline BoomLover

  • Trade Count: (1)
  • Senior Member
  • *****
  • Posts: 1152
  • Gender: Male
Re: Vent diameter to bore ratio
« Reply #1 on: August 03, 2012, 04:04:28 AM »
 Welcome to the Forum, by the way! Usually, your vent will be determined by size of fuse you are going to use, and make it a tiny bit larger. For instance, if your using 1/8th inch fuse, drill your hole at 3/16th inch. That will give your fuse room to burn, and make cleaning the vent a bit eaiser. BoomLover
Logged
"Beware the Enemy With-in, for these are perilous times! Those who promise to protect and defend our Constitution, but do neither, should be evicted from public office in disgrace!

Offline Artilleryman

  • Moderator
  • Trade Count: (0)
  • Senior Member
  • *****
  • Posts: 1378
Re: Vent diameter to bore ratio
« Reply #2 on: August 03, 2012, 06:54:32 AM »
If you are making a solid steel barrel you do not need to put in a vent liner. Vents are lined if you have sleeved the bore.  This provides a continuous passage way, otherwise a gap may open up between the sleeve and the barrel.  This gap could hold an ember that could set off the powder charge when you don't want it to.
Logged
Norm Gibson, 1st SC Vol., ACWSA
Pages: [1]   Go Up
« previous next »