Percussion, Loud Meter - Bore Diameter vs Length vs Charge

[nematode]

I know this is so old for most of you and probably posted about by newbies like me, hundreds of times. Sorry guys. I'm going to venture into a BP barrel in August. Have chosen the SuperX Dictator/Seige cannon from Brooks. I think that barrel will hold my interest a long time. I'm not like most of you though. I'm not planning a life-long hobby in BP cannons. My purpose is to adorn holiday celebrations with some charges and bangs of my own and that's about it.

My newbie questions:
Can you guys tell me which parameter has most impact on loudness of the bang and on the air repurcussion or percussion, whatever that air shaking, shock waving affect from cannon fire is?
1. Bore diameter
2. Bore length
3. Size of charge
4. Type of powder or other factors

[RocklockI]

Skip77 , that is a heck of a question and one i've pondered many time why is mortar quiter than a thunder mug ....chamber vs no chamber . what if you over fill the chamber for a blank ?

still not so much . at least w/o some waddage .

my best geuss is that there is a ratio of length to bore , my ..22's get quiter w/ a longer barrel to 26" .

i'll say an unchambered howitzer of @ 16 -20 cal. ...? thats my story .......may be even less ...

now i'm not talking about 16" by 55 cal. with modern powder .

just the older stuff and at our type scales .

[dan610324]

a cannon will always be louder than a mortar, its simple
the more volume in the bore the less pressure when the ball leave the bore
the more pressure the louder bang

[Rickk]

The SuperX Dictator/Seige cannon, when properly loaded, will be right up there with a 12 gauge shotgun in volume.

I have both the 1" Dictator (not the SuperX) and also the 1" Naval cannon, one a bit shorter and the other a bit longer than the SuperX. The longer Naval barrel is definitly louder than the standard Dictator but both are right up there with big smiles and lots of fun.

[Cat Whisperer]

There comes a point where the increase in dB is academic - when your eardrums meet in the middle you KNOW it's loud.

So, the shorter the barrel, to a point, the louder.  (more powder burning outside the tube)
The faster burning the powder, the louder.
Larger bore diameter requires more powder but gives a deeper voice.

The 8" howitzers could be heard (and windows rattled) some 5 miles away.  That is too loud.

I like letting loose with a deep throated boom and listening for the first echo from across town from the small mountain and then hearing it echo up and down the valley.  Beercan mortar with open topped can full of water does this.

3/4 and 1" bore signal cannons are great!

[nematode]

Thanks you all for the replies. I was ducking and expecting to get shellac'ed by a crew that was tired of answering these kind of questions. I'm delighted that so far all of you took me seriously and are actually answering my questions - outstanding!

I'm looking forward to the SuperX barrel. Currently, Brooks does not have them instock unless something has changed since my last email exchange with JB. I like the look of the regular siege mortars and would go that way at the same scale for cost saving but from what you have all told me the SuperX, having a similar bore but longer barrel, will sound louder. The small mortars are just cool, though, aren't they?

I've searched a lot of videos in youtube over the last couple weeks but the link below is one of my favorites. Pound for pound, my money says this little homemade cannon is about the loudest I've seen at this scale - your thoughts?  http://www.youtube.com/watch?v=43i8NRu2MoQ

[cannonmn]

The very most important factor is the range topography.  We usually shoot kind of nested among hills and the acoustic qualities of containing, reflecting, and/or amplifying cannon noise are wonderful.

[nematode]

yeah that is a great comment cannonmn.
that same notion dawned on me earlier today when i was outback firing the little 60mm carbide cannon off my tailgate. my truck was between a garage and my cottage... and pointing back into a kind of narrow space where trees on left, cottage on right and a gauntlet shaped yard stretched back behind, some 50 or 60 yards, walled by large mature trees. add that i live in a downtown area where many buildings are near and even that little carbide cannon, with it's tiny charge, sounded pretty dang loud! where we are firing is a big factor, indeed!

[RocklockI]

hearing it rumble thru the rockies is awsome .

[Cat Whisperer]

Thanks you all for the replies. I was ducking and expecting to get shellac'ed by a crew that was tired of answering these kind of questions. I'm delighted that so far all of you took me seriously and are actually answering my questions - outstanding!
...

We are fellow addicts.  We're here to support your habbit too!

[NitroSteel]

I think the angle of the barrel when it is shot is very important and certainly where you are standing in relation to the "business end" of the barrel when it goes off.  The boys in the hunting club a couple miles down the road actually got out of their deerstands one morning and came over to the house to see what was happening when we shot the bowling ball mortar a few times.  They said it sounded like the world was coming to an end.  I usually don't even wear ear plugs when I shoot it (from behind).  On the other hand, the seemingly loudest BOOM I've ever heard is one that comes from the golf ball mortar a friend of mine aquired from Victor3.  I wouldn't even think of shooting it or being anywhere near it when it goes off without ear protection (again).  From other experiences, I do agree with Cat Whisperer - I much prefer the deeper voice of the big bores over the "crack" of the smaller ones.  It does take more powder for the same effect though.  My rifled 30 mm Parrot is also very loud and has a "crack" to it, but I think, from behind the golf ball seems much louder - it's pointed at a 45 degree angle instead of straight away.

I've been wanting to ask the same question, but didn't really know how to phrase it.  And BTW - I never intended to have a shop full of cannons and mortars either, it just kinda happened.... .  I think this is a good thread, particularly since I have some quality material that I am undecided on what to do with

I love the volume and percussion as much as anyone.

[nematode]

Interesting observations by all. Good stuff!

[Double D]

We have been shooting the bowling ball mortar and the dom dictator pretty regular lately, been abit careless about hearing protection.  Then the other day I finally got the Cairo gun going again.  The first thing we all did after the first shot was start looking for our ear muffs.  Man that thing cracked.

I think the expansion chamber effect of the howitzer/mortar minimizes the sound. 

[BoomLover]

It's a sly one, Skip77! I too thought that just one would do me, love the feel of the concussion of the blast, but the sound, smoke, fire, and eventually target shooting will sneak up and bite you when least expected. I predict, and I'm sure many will agree, that soon enough you will be posting your latest pics of fire and smoke, and comparing targets from 50, 100, 200 yds and more, and measuring the loads, both powder and ball, Zinc vs lead. Like all of us, you start simple, with "just one", then you look over your shoulder and see they have multiplied! BoomLover

[NitroSteel]

You know you've got it bad when you start carrying your caliper with you everywhere - looking for ammo...

[Cat Whisperer]

You know you've got it bad when you start carrying your caliper with you everywhere - looking for ammo...

YUP!

If it's cylendrical the question is "what caliber is that?"

I'll bet you never thought that Coke and Pepsi are the same caliber!   

[b. snipes]

I'm a new guy here also. But, been making and firing cannons since high school shop. One of the medium loud units I have found is the thunder mug. Its short barrel (some power must burn in the open if loaded heavely) and the fact that when set on a flat surface to fire, exposes observers to its 360* concussion. I am a fan of the 1.750" bore size as it is plenty loud and can be used with a golf ball. In general though I am a blank load kind of guy. I gained a whole lot of respect when I had a Lyle gun and shot 4 lb slugs out of it with the 1/4 and 1/2 lb powder loads recomended. Very nasty recoil and powerful gun. Much more conservative now. beech........thunder mugs...thumbs up!