new cannon

[dan610324]

couldnt you turn it from a solid piece ??
thats the absolute best way to do it

[Victor3]

 One fairly easy way to fix your original barrel would be to bore a hole from the rear slightly larger than bore diameter and ~1" into the barrel tube. Then make a breech plug (maybe include a knob on it) to shrink-fit into it.

 You could even add a reduced diameter powder chamber in the front end of the plug if you wanted to. This would also allow you to put the vent further back.

[dan610324]

yeah but the shrink fit aint easy if you havent done it before
so to use a solid piece to start from would be the absolutely best way when you have equipment to do it
and also the best way for safety reasons

[dominick]

Without the proper equipment and knowledge,  heat shrinking a plug or "annealing" steel are the quickest methods to ruin the metal, especially if you're working with higher carbon steels like 4130/4140.  A mistake some make is to anneal or pre-heat their work by picking up the oxy-acytelene torch and applying heat. This also applies to heat shrink fitting a plug.  This type of work should be done with an oven under certain controlled conditions.  A Tempil chart is a good guide to understanding what happens to a piece of steel when it is heated.  Steel undergoes molecular changes at temperature as low as 300 degrees F.   I think most welding suppliers carry this chart.

I cold press the plugs into the barrels I make.  If the plug is prepared properly, it will not gouge the barrel or liner and will have a tight seal.

 

[oltom]

why not just get a new steel piece 1018 and turn one outta solid bar stock??

[dan610324]

exactly what I said

[porta mill]

well the problem with turning it out of solid materia.l I want a two foot barrel so a large enougth drill and long enougth boring bar is they are pricy . I am only building one gun so it is not practical for me to spend that much money. 

[dan610324]

cant you just use a standard drill and morse cone extensions ??

maybe Im too stupid to understand the problem

[Cat Whisperer]

By assembling  two smaller diameter pieces - tube and reinforcing band, hte steel cost is less than using a long full diameter piece and turning much of it into chips.

[dan610324]

yeah of course , but now the problem seem to be lack of proper tools

[dominick]

 Machining from a solid piece is the best method.  The down side to this is the larger the barrel the larger the equipment needs to be. 

[Soot]

cant you just use a standard drill and morse cone extensions

S&D bits have a flute length of 3 inches. Once the flutes get buried and the chips cant eject properly, you end up with real ugly rough bore problems.
You can peck away at it for hours but it only takes one chip jam to screw things up. Long boring bars can pile up chips in the chamber leading to the same problems also. This is what happens in my lathe, not sure about others.

[dan610324]

of course its problems with deep holes , but you drill and ream them for example
first open up the basic hole and then think about the finish
most standard drills are short yes , but just go 1 mm then go out and rinse it from chips and continue
it aint impossible

[oltom]

this hobby is habit forming!.....and one is never enuff!.I checked yesterday on my small 18" cannon's progress...well, the machinist hasn't even started~he does great work...but takes his time getting there!!!!!!
anyhoo...this is a 'test' to see how good he will do, and IF...i mean IF...i can raise the $$$...i may have him try a 12lb full size

he has the shopp...and he would try it.....but do i have the $$$ for a bar??  not right now!!!


but...there's always tomorrow!