Author Topic: Removeable breech plug (Read 706 times)

Kansas Boomer · « **on:** October 31, 2005, 06:17:45 AM »

Been thinking about having my 1" bore cannon remodeled. Would sure like to have a removable breech plug, for cleaning purposes only. When my machinist plugged the barrel last time, he said 2" of threads was just as strong as 2" of threads plus welding. Anyone have any thoughts or experience with removable breech plugs? Thanks, Kansas Boomer

Double D · « **Reply #1 on:** October 31, 2005, 07:40:25 AM »

A good way to go. I've done several that several that way. I used a set screw to hold the breech plug in. I also made a spanner to take the breech plug out.

I made the breech plugs just like an over sized breech plug in a muzzleloading rifle

Squire Robin · « **Reply #2 on:** October 31, 2005, 11:02:42 AM »

There are a pair of Japanese bronze cannon in the Rotunda at Woolwich with screw in breech plugs. Built to repel the English who were swanning about like they owned the place and generally annoying everyone, we confiscated them and now they want them back because they are totally unique. No chance :grin:

The Chinese also made a pair of cannon, not plugged like the Jap guns, enormous 24 pounders which did terible damage when our lads sailed up the river... Those are at Woolwich too :-D

Mons Meg has a screw in powder chamber IIRC.

Edit: Tell a lie, the Chinese guns were 6 inchers, whatever that is.

GGaskill · « **Reply #3 on:** October 31, 2005, 11:38:24 AM »

...the Chinese guns were 6 inchers, whatever that is.

30 to 32 pounders, depending on exact measurement.

If I were making a screw-in breech plug for a 1" bore gun, I would make the first inch or so unthreaded and as close a fit as possible to bore size, then thread the back inch or more. In use, I would heavily grease the plug including the unthreaded part, and screw in place. The grease and the unthreaded portion would prevent the powder fouling from getting into the threads which would make cleaning a lot easier.

Blaster · « **Reply #4 on:** October 31, 2005, 03:17:45 PM »

Quote from: GGaskill

...the Chinese guns were 6 inchers, whatever that is.

30 to 32 pounders, depending on exact measurement.

If I were making a screw-in breech plug for a 1" bore gun, I would make the first inch or so unthreaded and as close a fit as possible to bore size, then thread the back inch or more. In use, I would heavily grease the plug including the unthreaded part, and screw in place. The grease and the unthreaded portion would prevent the powder fouling from getting into the threads which would make cleaning a lot easier.

I have learned that greasing the threads does work but I later found that an application of "anti seize" compound, the type that you buy at the auto parts store is really better, making the threaded part much much easier to remove after firing. IMHO. Blaster

kappullen · « **Reply #5 on:** October 31, 2005, 04:10:42 PM »

You don't want any crevices, or cracks, or sharp corners to trap burning embers.

This is not likely with foil powder wrappers, but the NSSA and American Artillery Association insist on it.

That condition can lead to a pre-mature fire situation with not pretty results.

But you could paint the gun carriage red to not show the gore!

kap