Author Topic: Where to Get a Handgonne? - Part Two (Read 12709 times)

Cat Whisperer · « **Reply #30 on:** June 01, 2005, 03:47:47 PM »

Quote from: HotGuns

As one that uses Stressproof quite often I have to agree with Claypipes position about the crystaline structure of it.

In practical application, it could be argued that the 1144 would never see enough pressure to reach its elastic limit, but if it did it would come completely apart. Another thing to consider is the tempature that the chamber would see upon detonation of the powder. It could be that after an extended firing session where the barrel got hot that it could alter the heat treat of the metal somewhat.

This wouldnt be the problem with a steel of lesser heatreat or none at all,because the molecular structure of the metal wouldnt see the same change as one in a heatreated form.

Having studied cyrstalline stuctures of various steels that have been penetrated by amour piercing projectiles of various calibers and bullet makeup, I know that the immediate area of the pierced steel of the metal was quite different than the surrounding area that was unnaffected when checked under a microscope. The two different cystaline structures in the same area often resulted in cracking of the base metal, sometimes taking days after the shooting to become apparent.

With a combination of the heat, constant stretching that occures when a project moves down the barrel and limited amount of surface change that may occur to the metal in the powder chamber area, sometimes the "strongest" material in the rack as measured by tensile strength may not neccesarily be the best choice.

I have actually been considering building a handgonne and been paying attention to the posts. I had already decided to choose 12L14 for several reasons.One is that it will do the job. Two is because you can haul ass when machining it. Three is because I happen to have lots of it on hand. :-)

If I may summarize, you've made and well explained several very good points:

a) 1144sp has crystaline structure (more so than 12L14) hence prone to fracture if pushed past elastic limits.
b) 1144 has much stronger than 12L44, but 12L44 is plenty strong.
c) Specific functions of interior ballistics may well affect the nature of the metal on the surface of the bore, hence leading to failure.
d) 12L44 is MUCH more machineable than 1144 (or most anything else).

Hotguns - thank you from speaking from experience and adding a bit of clarity to this issue.

claypipe · « **Reply #31 on:** June 01, 2005, 03:52:40 PM »

Quote from: HotGuns

As one that uses Stressproof quite often I have to agree with Claypipes position about the crystaline structure of it.

In practical application, it could be argued that the 1144 would never see enough pressure to reach its elastic limit, but if it did it would come completely apart. Another thing to consider is the tempature that the chamber would see upon detonation of the powder. It could be that after an extended firing session where the barrel got hot that it could alter the heat treat of the metal somewhat. )

There's one other problem with stressproof. Micro fractures that can occur with the quenching process. Hence the need to magna flux or x-ray such material.

Quote

Having studied cyrstalline stuctures of various steels that have been penetrated by amour piercing projectiles of various calibers and bullet makeup, I know that the immediate area of the pierced steel of the metal was quite different than the surrounding area that was unnaffected when checked under a microscope. The two different cystaline structures in the same area often resulted in cracking of the base metal, sometimes taking days after the shooting to become apparent.)

Either you're employed with a company producing bullet proof vests or you're in government weapons research or employed by a contractor for the same.

Quote

With a combination of the heat, constant stretching that occures when a project moves down the barrel and limited amount of surface change that may occur to the metal in the powder chamber area, sometimes the "strongest" material in the rack as measured by tensile strength may not neccesarily be the best choice.

AMEN, Brother!

Quote

I have actually been considering building a handgonne and been paying attention to the posts. I had already decided to choose 12L14 for several reasons.One is that it will do the job. Two is because you can haul ass when machining it. Three is because I happen to have lots of it on hand. :-)

PM me, I'd love to compare designs. :grin:

Cat Whisperer · « **Reply #32 on:** June 01, 2005, 04:45:31 PM »

Quote from: CAV Trooper

.... First off, my PRIMARY concern is safety. ThatÂ’s why IÂ’m doing a rethink on the materials to be used for the handgonnes we want to make. The absolute LAST thing any of us want is for somebody to get hurt...

I think we can ALL agree on that. That's the reason we're taking this one step at a time, and publicly so that the relevant issues can be discussed.

It is because of that need for safety, that we need to listen to all perspectives - there are some things that don't apply, but that will be obvious as the facts accumulate and we get a good well-rounded perspective of the design principles.

We have yet to hear from a metalurgist or a mechanical engineer involved in this type of design. I don't expect it. We have heard some good design issues and there are more - noteably the rounding of interior corners to elimitnate or limit stress points.

While a FEA program would be useful (Finite Element Analysis) in calculating the internal stresses based on 3D cad models - we can rely on successful designs of the past - and these will come out.

Blaster · « **Reply #33 on:** June 01, 2005, 04:46:36 PM »

Mr. Websters book shows the words: TACT = implies the skill in dealing with persons who have a quick delicate sense of what is fitting and thus avoids giving offense.
And DIPLOMACY = implies a smoothness and adoitness in dealing with others. :wink:
I sure hope that I am always tactful and diplomatic!! And now, back to my mortar cleaning.

John N · « **Reply #34 on:** June 02, 2005, 02:30:04 AM »

Back to Cav Trooper's proposal. There seems to be general agreement that 12L14 would be a pretty good choice of materials. I did a quick check on the Internet to get some ideas of material costs and found 12" long pre-cut pieces of 1-1/4" round 12L14 steel for $10.08 each.

Third_Rail · « **Reply #35 on:** June 02, 2005, 05:12:16 AM »

Apparently 12L14 may not be a good idea to use, either. :?

Until we can get solid information, I'd say put this project on hold - or just use 4140/4130.

CAV Trooper · « **Reply #36 on:** June 02, 2005, 06:43:14 AM »

Since Safety is our primary concern, using 4140 for the handgonne barrels is a good choice.

However, for the purpose of discussion, what are the problems with 12L14? IÂ’ve read several Â“opinionsÂ” about it here but have yet to see any real facts. As I wrote previously, the Canadian Cannon Company has made their barrels out of 12L14 and C360 for years and IÂ’ve yet to hear anything negative about them. In fact, even a self-proclaimed expert Â“gonnemeisterÂ” recommended using it.

Cat Whisperer · « **Reply #37 on:** June 02, 2005, 06:55:48 AM »

My .90 cal. handgonne is of 1018 - powder chamber of about 1/2" diameter x 1" depth with a 5" bore. 1018 may not be as easy to machine as 12L14 but they're not all that different in strength. Both, being mild steels have similar ductility characteristics and strength.

Both, again, are much stronger than the original materials use a few hundered years ago.

For safety we're looking not a machineablity but at some other things:

strength, reaction to being fired many times, and (perhaps) crystaline structure IF loaded well beyond design strength.

4130/4140 goes beyond 1018, 12L14 in wear characteristics - but I don't think that's an issue in smoothbore. It also has a good history of use in ballistic applications.

John N · « **Reply #38 on:** June 02, 2005, 07:43:18 AM »

Cav Trooper - probably time to start a Part 3 for this discussion. :wink:

1-1/4" ROUND 1018 STEEL 12" PRE-CUT -$7.25 a piece

1-1/4" ROUND 4140 CDA STEEL - $1.09 per inch

Difference in cost of machining? -

??

Safety?

Priceless.........after all, the shooter is holding a handgonne (with their weak hand inches away from the "action"), unlike a cannon or mortar where you are at least 5 feet behind (lanyard firing) and 10-20 feet or more away when using fuse.

claypipe · « **Reply #39 on:** June 02, 2005, 08:24:00 AM »

Quote from: Third_Rail

Apparently 12L14 may not be a good idea to use, either. :?

Until we can get solid information, I'd say put this project on hold - or just use 4140/4130.

My understanding is that both Getz and Colerain use 12L14. Green Mountain is now using 1137 for their BP barrels and 4140 for their BPCR barrels. Just remember that what ever steel you use, it has to expand and contract. Using 1144, IMHO, is asking for trouble. But if money is no object, then go for the 4140, its rated for smokeless. Just keep your cutters sharpened.

Third_Rail · « **Reply #40 on:** June 02, 2005, 09:42:39 AM »

I think I'm going to go the tougher route and use 4140 on all of my future pieces. Time isn't expensive, but it sure is hard to re-grow a limb.

Good question, though - should one leave 4140 as is once machined, or would hardening it (to specifications used by Krieger, others) be a good idea for even more safety?

CAV Trooper · « **Reply #41 on:** June 02, 2005, 11:05:31 AM »

Due to it's extremely high strength, 1144SP originally looked like the best material for this project. However, having now learned that it can also become brittle and possibly shatter upon firing absolutely excludes it from being used.

Earlier today I sent an email to everybody who has expressed interest in purchasing a handgonne and advised them that I was going to use 4140 instead. My machinist friend works with the stuff all the time and has no problem with it.

Due to some personal reasons involving family, I unfortunately can't keep this project open and sitting still. That being the case, I plan on ordering the raw bar stock by next Monday at the latest.

If there's anybody who is interested in one of these handgonnes and hasn't contacted me yet, please do so ASAP.

GGaskill · « **Reply #42 on:** June 02, 2005, 11:28:26 AM »

Heat treating 4140 after machining can cause dimensional changes and warping, one reason why specialty action makers heat treat first and machine second in spite of the difficulties caused by the hardened material.

But don't rely on the additional strength of heat treating as your sole source of safety. Design is more important, including appropriate use of safety factors. And unless you are willing to get into non-destructive materials testing (or pay for material that has been so inspected), you should proof test the completed project to catch any manufacturing screw ups or hidden material flaws. You might find this article assessing an M1A barrel failure interesting.

Third_Rail · « **Reply #43 on:** June 02, 2005, 01:15:10 PM »

Thanks for the article - reading now.

As for the design, trust me, I want excessively strong.... As in, 1" bore, 3" or more OD for an 18" bbl. Safety is my thing.

:eek:

Wow. I think I'll avoid heat treating, afterall... Unless I find a professional to heat treat my things, that is. Even then... geeze. I'd rather just use more of the 4140 and increase the safety that way than make a thin barrel and risk a mistake like the wrong temperature, wrong time, etc. in heat treating.

GGaskill · « **Reply #44 on:** June 02, 2005, 01:46:54 PM »

We can discuss, hash and rehash materials and design all we want but the safety issue has to include charge weight and projectile weight to be addressed completely. While I suppose it would be possible to make a gun that was incapable of being blown up no matter what charge and weight of shot were used, it would be of no use (too small) or unusable (too large.) We have to compromise infinite safety for practicality. And that compromise is the use of weights of charges and shot that can be safely fired from the design chosen for use even though larger charges are possible.

Think about centerfire cartridge rifles. The reloading tables, especially for the magnum cartridges, contain loads that are probably within 10% of being excessive, especially the older manuals that didn't pressure test the data. Yet most users of the data are content to carefully use the data as presented without concern that another 5 or 10 grains of powder will blow them to kingdom come; they don't intend to load there. The same thing has to apply with muzzle loading cannon, handgonnes, and anything else that allows the firer to choose how much powder and how many shot go into the bore.

Third_Rail · « **Reply #45 on:** June 02, 2005, 02:11:43 PM »

Very true re: charge, projectile. For example, I intend to build a functional 4 gauge muzzleloader - never to use more than a 1/4lb projectile (the 4 gauge roundball), never to have a higher charge than 150 grains of Fg, and that would be an absolute maximum charge. We'll see what other info I can dig up, but the max charge is normally 250 - I'm not ever going to go into that range.

GGaskill · « **Reply #46 on:** June 02, 2005, 02:28:46 PM »

Have you seen these pages regarding a 4 bore double rifle?

http://www.african-hunter.com/4-bore_part_i.htm

http://www.african-hunter.com/4-bore_part_ii.htm

Third_Rail · « **Reply #47 on:** June 02, 2005, 03:35:02 PM »

Yes, I saw them quite a while back when doing research. Since he uses significantly less steel, although heat treated (not to mention smokeless), I should be fine with my "short" 4ga (being a lesser black powder charge and all).

Cat Whisperer · « **Reply #48 on:** June 02, 2005, 03:44:50 PM »

Quote from: Third_Rail

... For example, I intend to build a functional 4 gauge muzzleloader - ...

We are genuinely anxious for you to finish this and post the pictures!

I will say, though, having shot lots of .458WM 500gr maximum loads (sometimes up to 50 a day) that I personally only want to fire it once - to be able to say that I had.

Third_Rail · « **Reply #49 on:** June 02, 2005, 04:31:05 PM »

Well, being a BP piece, once completed, proofed, tested, etc. to my satisfaction.... Pictures will be here. :grin:

claypipe · « **Reply #50 on:** June 02, 2005, 07:44:15 PM »

Quote from: Third_Rail

Very true re: charge, projectile. For example, I intend to build a functional 4 gauge muzzleloader - never to use more than a 1/4lb projectile (the 4 gauge roundball), never to have a higher charge than 150 grains of Fg, and that would be an absolute maximum charge. We'll see what other info I can dig up, but the max charge is normally 250 - I'm not ever going to go into that range.

Since I have not seen your design, I have to ask the following questions:

What is the bore length?

Have you given any thought to sub-caliber powder chambering?

What bore diameter? 1.0" or a true 1.052?

What size ball? .990 or .995?

Patched or not patched?

Firing Handheld or Mounted?

Cat Whisperer · « **Reply #51 on:** June 03, 2005, 12:39:02 AM »

Claypipe -

Excellent questions. Let me add just one - shape of the inside corners - rounded or square (obviously rounded greatly reduces the stress points).

claypipe · « **Reply #52 on:** June 03, 2005, 01:21:21 AM »

Quote from: Cat Whisperer

Claypipe -
Excellent questions. Let me add just one - shape of the inside corners - rounded or square (obviously rounded greatly reduces the stress points).

Well with a spec of 3" 4140 stock, inside corners aren't really a stress issue. Though rounded would definitely help to focus the charge up the bore. This piece would definitely handle a charge of 150 grains with the greatest of ease.

Cat Whisperer · « **Reply #53 on:** June 03, 2005, 01:37:32 AM »

Quote from: claypipe

Quote from: Cat Whisperer
Claypipe -
Excellent questions. Let me add just one - shape of the inside corners - rounded or square (obviously rounded greatly reduces the stress points).

Well with a spec of 3" 4140 stock, inside corners aren't really a stress issue. Though rounded would definitely help to focus the charge up the bore. This piece would definitely handle a charge of 150 grains with the greatest of ease.

IT is not the 'focusing of the charge' that is the issue. It is a simple thing to round the inside corner - the effect is to spread the stresses instead of concentrating the stresses at the point of the corner. A sharp corner has many many times the level of stress as the surrounding area - a potential cause for failure. Simple to avoid, prudent to DO.

claypipe · « **Reply #54 on:** June 03, 2005, 03:47:04 AM »

Quote from: Cat Whisperer

Quote from: claypipe
Quote from: Cat Whisperer
Claypipe -
Excellent questions. Let me add just one - shape of the inside corners - rounded or square (obviously rounded greatly reduces the stress points).

Well with a spec of 3" 4140 stock, inside corners aren't really a stress issue. Though rounded would definitely help to focus the charge up the bore. This piece would definitely handle a charge of 150 grains with the greatest of ease.

IT is not the 'focusing of the charge' that is the issue. It is a simple thing to round the inside corner - the effect is to spread the stresses instead of concentrating the stresses at the point of the corner. A sharp corner has many many times the level of stress as the surrounding area - a potential cause for failure. Simple to avoid, prudent to DO.

I think you missed the fact that I agreed with rounding the corners. But using 3" 4140 stock, failure is not that serious an issue with 1.5" walls for a 1.0" bore. As a gonner, to me, definitely safety first. But focusing the charge to maximize the speed of the ball comes next. In focusing the charge out the bore, does that not lower the stress on the breech and walls? Either way you want to look at it we both agree on rounding.

(argumentative/inflammatory remark(s) deleted by DD)

One would have to seriously overload and triple ball a barrel like that to even attempt to get it to fail.

Third_Rail · « **Reply #55 on:** June 03, 2005, 06:46:30 AM »

What is the bore length?
Barrel length will be 16" overall, actual bore length will be 14", with the last 2" left solid.

Have you given any thought to sub-caliber powder chambering?
Yes, I'll be throwing 150grains of 1Fg BP and seeing how many ml it takes up, then drilling a chamber to fit that - like I said, I'll never be using more than 150 grains so it wouldn't be an issue.... If I used less, though - would that ruing the barrel like in a muzzleloader? Perhaps I'll forego the chamber.

What bore diameter? 1.0" or a true 1.052?
1", since that will be significantly easier to drill to the depth I need. (already have good bits, good reamers, etc., in this size)

What size ball? .990 or .995?
Thinking smaller than that to start, .975 or .980. Have to see what happens, before I think of sticking a tighter fitting ball down there.

Patched or not patched?
Not patched, again the idea of sticking a tightly fitted ball down a (smooth) bore doesn't make a whole lot of sense - no rifling to grip at first.

Firing Handheld or Mounted?
First few shots (and measurements, etc) will be mounted, so to speak. The design itself is for a stocked firearm, though.

Third_Rail · « **Reply #56 on:** June 03, 2005, 06:48:57 AM »

Quote from: Cat Whisperer

Claypipe -

Excellent questions. Let me add just one - shape of the inside corners - rounded or square (obviously rounded greatly reduces the stress points).

Rounded. It's a quick operation, and that would be something that is normally thought of as a "good idea". Couldn't hurt, anyway! :grin:

HotGuns · « **Reply #57 on:** June 03, 2005, 08:15:05 AM »

Not to mention that anything with rounded shoulders is going to be much easier to clean....

A sharp shoulder holds alot of crude that could start corrosion. Being that its a stress riser anyway it is not a good thing.

CAV Trooper · « **Reply #58 on:** June 03, 2005, 09:20:31 AM »

All,

While some very good information has been brought out, and I'm sure we've all probably learned things, this whole project has gone off in a direction that wasn't intended.

As of this time, and until further notice, the handgonne building project is on indefinite hold and nothing further regarding it will be posted here.

As DD wrote elsewhere, the stated purpose of the board is the discussion of Cannons and Mortars and I think it's time we go back there. Handgonnes are actually off topic and unfortunately have caused way too much divisiveness.

For those of you who expressed interest in the project, I'll be in contact with you off line. Anyone else who wishes to discuss the project is also welcome to contact me.

Cat Whisperer · « **Reply #59 on:** June 03, 2005, 09:31:07 AM »

Quote from: CAV Trooper

...As of this time, and until further notice, the handgonne building project is on indefinite hold and nothing further regarding it will be posted here.

As DD wrote elsewhere, the stated purpose of the board is the discussion of Cannons and Mortars and I think it's time we go back there. ....

Agreed, someday in the future maybe, but for now back to business.