Author Topic: 40 MM Rifled Breach Loader (Read 15912 times)

GGaskill · « **Reply #30 on:** May 22, 2011, 02:51:18 PM »

So the constriction could very well be the cause of the mysterious fliers I am getting

Unless you are shooting steel projectiles, they will be swaged to pass the constriction and be loose in the barrel after that, depending, of course, on how much constriction there is. A loose fit at the muzzle is not a good thing.

moose53 · « **Reply #31 on:** May 23, 2011, 06:42:34 PM »

Finished the powder chamber today . The handy extension used with the die grinder is a 3/8 in shaft turned down to 1/4 in on one end and drilled for 1/4 in on the other . The thread is 1/4 in pipe and the cap is a 1/4 in brass pipe cap . It works best to start the thread and then cut the slots and then finish threading , you get more grip.

moose53 · « **Reply #32 on:** May 25, 2011, 06:13:15 PM »

The barrel and breech are now together . The set of photos show uniform contact test (red grease) , aviation gasket sealant used to permanently seal the threads from any corrosion, and setup used to torque the barrel and breech together( barrel is chained to the floor) . Torque used was 250lbs at 5-1/2 ft or 1,375 ft/lbs , barrel should stay on. Areas with pipe wrenches marks will be machined down .

moose53 · « **Reply #33 on:** May 26, 2011, 06:32:14 PM »

Machined the bullet chamber today . The small diameter of the breech block was left at the land diameter of the barrel so that by using a reamer I made, the breech and barrel could be matched perfectly . The barrel was also free bored ( rifling removed ) for 1/2 in at the same time . Reamer was made to just fit the land dia .

Frank46 · « **Reply #34 on:** May 27, 2011, 06:16:48 PM »

Moose, I have to hand it to you and the others here who have made their own cannons. The machine work is excellent. And thank goodness for very large pipe wrenches. Frank

moose53 · « **Reply #35 on:** May 28, 2011, 05:34:39 PM »

Thank you , cannons are definitely a labor of love. Finished the Obturator today , it is very simple to adjust , set the breech screw in the breech block against the shouldered backing washer and then tighten the Obturator spindle nut until it just gets tight .

Frank46 · « **Reply #36 on:** May 28, 2011, 06:09:44 PM »

Moose, let me see if I have this obturation thing down pat. After you pre-load the obturator then the force of the expanding powder gasses further compresses it in effect sealing off the breech right?. keep up the good work. Frank

moose53 · « **Reply #37 on:** May 28, 2011, 07:44:06 PM »

Yes That is how it works . I also lube it with vegetable oil so it will move in and out easily , the front steel backing and the aluminum foil powder container effectively protect it from the hot gas.

Frank46 · « **Reply #38 on:** May 29, 2011, 06:20:20 PM »

Moose, well I finally got something right. I used to repack pumps both reciprocating and rotating and at 300 psi there was very little room for error, got more than one oil bath when it wasn't done right. Am enjoying the progress. Frank

moose53 · « **Reply #39 on:** May 30, 2011, 07:06:23 PM »

Made the breech screw handle today , needs a little more finish . The reversed photo shows the impact lug , the screw will have one also. Tried plug welding the lug on but I am not entirely happy with it . On my previous guns I had one screw and two hard dowel pins to hold the lugs in place , think I will go back to that .

Cannoneer · « **Reply #40 on:** May 31, 2011, 02:41:01 AM »

moose53,

Is the breech screw handle cast aluminum?

moose53 · « **Reply #41 on:** May 31, 2011, 03:57:29 AM »

No it is welded steel parts , sand blasted to show up any humps I can even out.

moose53 · « **Reply #42 on:** June 02, 2011, 04:49:14 PM »

Repaired the impact lugs today . Detailed the hinge ring and breech screw nuts . Breech spindle needs to be fitted for a spring slap hammer and then cut to length.

GGaskill · « **Reply #43 on:** June 02, 2011, 05:51:54 PM »

So how many turns are required to open the breech?

moose53 · « **Reply #44 on:** June 02, 2011, 06:21:37 PM »

I think six . I need to count to be sure , but that is close . The breech is +or- 3 inches not counting ring , and pitch is 2 treads per inch.

Cat Whisperer · « **Reply #45 on:** June 06, 2011, 05:14:38 PM »

Out of the run-of-the-mill for here. I LIKE IT!

moose53 · « **Reply #46 on:** June 08, 2011, 07:20:58 PM »

Thank you Cat Whisperer. The barrel is starting to take shape now . I dealt with the trunnion sleeve collapsing the barrel by making a sleeve to weld to the breech block and then weld the trunnion sleeve to it. Both sleeves are a slip fit. The muzzle boss and threads for the flash cone have also been removed.

Cannoneer · « **Reply #47 on:** June 08, 2011, 09:04:27 PM »

It's getting gooder and gooder; keep the pics coming.

dominick · « **Reply #48 on:** June 09, 2011, 02:47:53 AM »

moose, Do you know what type of steel these rifled barrels are made of? How did it machine?

moose53 · « **Reply #49 on:** June 09, 2011, 04:26:34 AM »

You can tell the barrel steel is tougher then normal , I just call it it ordnance steel . It cuts very nice with carbide tooling , not gummy , clean and sharp . Files nice also , good detail.

guardsgunner · « **Reply #50 on:** June 09, 2011, 10:06:14 AM »

Moose,
Is your barrel magnetic?

Victor3 · « **Reply #51 on:** June 09, 2011, 10:04:46 PM »

Quote from: dominick on June 09, 2011, 02:47:53 AM

moose, Do you know what type of steel these rifled barrels are made of? How did it machine?

I have a chunk of this bbl (Bofors/Bushmaster). Soon as I get time I'll cut a piece off and send it to the lab. IIRC it's similar to 4140.

Didn't I already do this once? Oh look, a chicken!

moose53 · « **Reply #52 on:** June 10, 2011, 04:29:29 PM »

Yes barrel is magnetic. Finished the trunnion block today .

Cat Whisperer · « **Reply #53 on:** June 10, 2011, 04:32:22 PM »

Cool technique (of alignment of the trunnions) for a sleave that goes around THE barrel. !!

moose53 · « **Reply #54 on:** June 10, 2011, 04:37:18 PM »

Yes it works very well

moose53 · « **Reply #55 on:** June 11, 2011, 07:40:07 PM »

Welded up the trunnions today , had to try it out on my old carriage to see how it fit . Excuse the rubber wheels they are for towing it behind a vehicle . I have a set of wood wheels that aren't finished yet.

moose53 · « **Reply #56 on:** June 12, 2011, 06:33:20 PM »

Made my loading tube today , It is hard plastic and the right color . The chrome rod is for tightening it for a good seal when cleaning ,keeps the crud out of the threads.

moose53 · « **Reply #57 on:** June 15, 2011, 07:02:31 PM »

Was not happy with the 3/8 in handle for the loading tube so changed it to 1/2 in handle and made it shorter , seems to work better. Made the tooling for the aluminum foil cartridge today . It is set for max load of 8 oz , I use homemade powder so that is not as much as commercial powder would be . My regular load would be about 6 oz. Aluminum foil cartridge is indented to fit the obturation spindle hex head .

Cannoneer · « **Reply #58 on:** June 16, 2011, 02:40:16 PM »

That's very clever, Moose.

Quote from: moose53 on June 12, 2011, 06:33:20 PM

Made my loading tube today , It is hard plastic and the right color . The chrome rod is for tightening it for a good seal when cleaning ,keeps the crud out of the threads.

moose53 · « **Reply #59 on:** June 16, 2011, 07:31:32 PM »

Thank you , I am glad you like it . Detailed the breech block today , the major component left is the hinge .