Author Topic: BRASS BARRELS (Read 1152 times)

irishman · « **on:** November 24, 2005, 02:54:43 PM »

I derive such pleasure and knowledge from this site. What great comraderie among GBO members! I am going to try to post a picture to show some of what my shop produces. My specialty is turning FC360 extruded brass, which is one of several excellent materials for the manufacture of cannon barrels.

I have built a variety of barrels from .177 up to D cell size bores, and soon will produce my first golf ball mortar. You can see Ray89's influence on the micros (see Backyard Cannon Fun). Working on a surprise project for release in the Spring. Also have a 58 pound piece of 5" diameter stock that is driving me up a wall...

I will be listing some stocking stuffers in the classifieds in the next few days; and you can view our other items at www.brooks-usa.com
Michael

Cat Whisperer · « **Reply #1 on:** November 24, 2005, 03:24:19 PM »

Michael -

We look forward to your 'stocking stuffers'. Great idea!

Good to see the picture too! I'm afraid I've only turned one piece of brass - when I needed a step of 1/8" diameter on a 3/16" pin to hold the screen in the door on the back poarch. So, I for one, would love to see the processes and techniques of turning brass.

rays89 · « **Reply #2 on:** November 24, 2005, 04:01:52 PM »

Micheal
So thats how it looks on "your side of the woods" As for a brass Golfball size Coehorn Mortar, Count me on that one. That should be pretty sweet.
Ray

irishman · « **Reply #3 on:** November 24, 2005, 04:04:51 PM »

C.W.

Stocking stuffers will appear soon. FC 360 cuts like butter! It is a delight to work with. On a "machinability chart", it, by itself is listed as 100%.

Michael

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kappullen · « **Reply #4 on:** November 27, 2005, 03:09:32 AM »

Where's the steel liners you guys are always harping about?
kap

irishman · « **Reply #5 on:** November 27, 2005, 06:30:42 AM »

Kap,

We have never used a steel liner. We keep plenty of beef in the wall. One of the more frequent comments about our barrels is "over built".

About the only "brass", steel lined barrels that I see, aren't really brass. They are usually a cast bronze from overseas. The alloy changes from day to day, making it impossible address "strength of material".

There certainly is a place for sleeves. My shop is geared to make multiples of the safest, best quality barrels at a fair price. The frequent comment often heard right before overbuilt is "beautiful workmanship".

We guarantee every barrel that we sell!

Michael

Double D · « **Reply #6 on:** November 27, 2005, 07:27:51 AM »

Kap,

I too share your concern about the lack of liners or at least the use of brass for larger guns.

Since the steel liners for full size guns are rated for 80,000 to 85,000 psi I would think brass of comparable strength would be required to meet the safety parameters.

I looked through my library for information on pressure in black powder cartridges. The only thing I could find was in Wolfe's book on the 45/70 Trapdoor in an old arsenal reference listing the 45/70 service cartridges at 19,000 lbs.

FC 360 is rated at 45,000 psi yield strength. I would want to see some pressure testing of its strength before I used it for more than small cannons.

Some expansion testing like Claypipe did with his handgonne would be interesting.

The rule of thumb for breech wall thickness would be the starting point for such a test. Breech wall thickness equals diameter of the powder chamber. Load a max load and fire. Measure for expansion. Repeat the test say 10 times and remeasure after each shot.

This might be one area to heed Switliks results. Start with cannon grade powder then go to FG and see if the brass will stand to the 40% increase in pressure FG gives over Cannon Grade.

gary michie · « **Reply #7 on:** November 27, 2005, 05:32:55 PM »

hello again
I have ask power manufactures about blackpowder and got; I don't know, from all of them. Old artillery papers say the 20 lb. parrott rifle only produced 4500 psi that sounds low but it was a government paper. I have heard 17000 psi batted around a lot so I,ve used the latter in my arguments. Here in washington state the civil war artillery guys said to me naval bronze only and sleaved no brass period hence there are no bronze guns at reenactment events. It would be nice if there was a TABLE listing the differant grades and makes of powder and their proformence.
gary

GGaskill · « **Reply #8 on:** November 27, 2005, 08:05:37 PM »

I just bought an Oehler Model 43 and intend to do some quantitative pressure testing of black powder in the future. One of the handicaps of the strain gage testing system is wall thickness. The walls have to be thin enough for them to expand so the gage can detect the expansion. So I will have to start with barrels with thinner than scale dimensions. This will be a long term project but I will publish the raw data as it accumulates.

gary michie · « **Reply #9 on:** November 28, 2005, 07:36:25 AM »

Quote from: GGaskill

I just bought an Oehler Model 43 and intend to do some quantitative pressure testing of black powder in the future. One of the handicaps of the strain gage testing system is wall thickness. The walls have to be thin enough for them to expand so the gage can detect the expansion. So I will have to start with barrels with thinner than scale dimensions. This will be a long term project but I will publish the raw data as it accumulates.

GREAT
WONDERFUL I will help if it is possible.......!!!
gary

russianblood · « **Reply #10 on:** December 03, 2005, 02:07:39 PM »

I just ordered one of the 22 cal stocking stuffer mortar barrels. I was wondering if it comes with directions. I plan on buying a tin of 22 cal BBs and see what damage I can do to a cardboard box with it. :grin:

I also look foward to making a sled to mount it on.

irishman · « **Reply #11 on:** December 04, 2005, 12:39:14 PM »

russianblood--

Excellent! Your order will ship tomorrow, along with info pages. We look forward to seeing the completed project. Thank you, Michael