Fireballs!!

[zardoz]

Hello all:

I got the urge today, to load up some shotgun shells. Todays recipe from the Lyman manual.

Hull: Winchester 2 3/4" AA HS
Wad: Winchester WAA12R
Powder: 44 grains Blue Dot
Primer: Winchester 209
Projectile: 525 Lyman Sabot Slug cast from ACWW.

Gun: Remington 870 Express Super Magnum, w/ 20" fully rifled barrel.

On a whim, I took some video of me at my range behind the house, to see how I would react to the recoil (it was pretty stout)

On review, I found that I had a couple of frames in the video, where I caught the massive fireball at the exact millisecond.

So without further delay, here for your amusement, are the fireballs.

http://myfiero.com/uploads/17942_.jpg

http://myfiero.com/uploads/17943_.jpg

BTW, that is a Competition Electronics ProChrono II that is getting flamed (literally).

[lurch]

Don't know about the rest of the world, but after seeing that, I'm glad I back off about 10ft from my screens. I don't think that the fire is an issue - duration is way too short - but the blast wave can't be too friendly to the innards of that chrono in the long run. I suspect that over time, too much of that is going to shake something loose that shouldn't be.

That should certainly get a whitetail's attention..whether you hit it or not. Impressive stills BTW.

[Johnch]

:bigsmyl2: Don't you just Bluedot :bigsmyl2:

But how did the load shoot ?



I used to shoot a lot of trap and play the games from the 27 yard line and farther back
I used to scare the snot out of the next shooter with a load of 37 gr of BD and 1 1/4 oz oz shot at 1440fps

Out of a ported barrel the fire not only exits the muzzel
But a fireball shoots out of the ports [smilie=l:
And the BOOM rattles your brains

I had more than 1 guy start to flinch so bad , I was completely safe if I missed :holysheep

John

[454PB]

I'm surprised you can get a reading with the chronograph so close to the muzzle.

When I chrono my .300 and .338 magnums, I have to be as far as the cord allows or I get erratic readings.

[SierraWhiskeyMC]

That's a heck of a fireball!

Definitely move that chrono further out. That close in, it's like whacking it with a sledgehammer.

[runfiverun]

i set mine at 10' also i seem to get more consistent readings that way.
reminds me of some 7.7 loads i made up for my girls rifle,needless to say she didn't much like them.
you might wanna try steel powder.

[zardoz]

Yea, I was standing too close to get good readings. Most were errors. The few good readings, were around 1450 ft/s.

Normally, I'm well inside the screen tent (that catches my semi-auto brass).

The chrono manual recommended standing in close when shooting slugs and buckshot, to avoid the wad separating and hitting the screens. On the video, you can see the muzzle blast flexing the sky screens back, so definitely too close.

I was more concerned with getting the video made, so the chrono readings were sort of second priority.

Interesting stat. According to the Thornily Stopping Power calculation, given 525 grain projectile, of 0.692" diameter, traveling at 1450 ft/s, has a factor of 280.

http://www.beartoothbullets.com/rescources/calculators/php/thornily.htm?v1=525&v3=.692&v2=1450

Rhino, Hippo, Elephant, and Cape Buffalo stopper it suggests. Hmmm.

[Dale53]

zardoz;
I have seen more than one itty bitty deer to absorb a load of that level placed in the chest cavity that ran off to be lost (mainly because the shooter couldn't track a deer and assumed because the deer didn't fall over at the shot, he missed).

Not knocking your presentation (loved the timing of the shots) but even tho' those loads are "whomper-stompers" it doesn't necessarily mean instant kill, even on a small deer. I have recovered several deer that other hunters left in the woods with good hits that ran off a ways and were lost. Just in case you think I may have "stolen" them, I ALWAYS try to find the original hunter. Sometimes I have been successful and sometimes it is a day or two later that I have stumbled upon the deer and it is too late for anyone but the coyotes.

FWIW
Dale53

[Thumbcocker]

The same slug with the charge of universal reccomended in the Lyman shotgun manual shoots good with a bit less recoil. Back when I hunted with a slug gun it was my go-to load. I never lost a deer hit with that slug cast out of pure lead.

[lylejb]

Rhino, Hippo, Elephant, and Cape Buffalo stopper it suggests

I'm sure it would stop any rhino that might charge you in Tenn:bigsmyl2:

That's the problem with so many of these "calculators" They miss too many real world factors.

According to this calculator, a .357mag is barely enough for deer, a .44mag ISN'T enough for a black bear, and a .30-06 ISN'T enough for elk. Yet we know all of these calibers, and many lesser, have been used sucessfully for years.But your shotgun slug IS fine for elephant:veryconfu

I don't put any faith in any calculator i've seen so far. I think of them as "for entertainment purposes only".

Zardoz, nice post, i like the pic's. My son was very impressed to see the big fireballs. Thanks again.

[Tom W.]

WoW! Kill it and cook it all at the same time!

[Rocky Raab]

Look very carefully and you will note that the pictures are yet more evidence of my contention that powder does NOT burn all the way down the barrel and beyond. In both frames, you see a small glowing ball at the muzzle, and then several inches of clear air BEFORE the rear edge of the fireball.

What happens in virtually all cases is that the powder produces excess amounts of flammable gasses, but insufficient oxygen to consume them. Powder "burns rich" as the engine guys would say. When those flammable gasses - still way above auto-ignition temperatures - mix with atmospheric oxygen, the fireball begins. That cannot happen until some small distance beyond the muzzle.

Here's a much larger and even more dramatic example of the fireball not forming until well downrange...

http://i27.photobucket.com/albums/c170/RockyRaab/USSidahookinawa1april1945.jpg

[Ricochet]

Look very carefully and you will note that the pictures are yet more evidence of my contention that powder does NOT burn all the way down the barrel and beyond. In both frames, you see a small glowing ball at the muzzle, and then several inches of clear air BEFORE the rear edge of the fireball.

What happens in virtually all cases is that the powder produces excess amounts of flammable gasses, but insufficient oxygen to consume them. Powder "burns rich" as the engine guys would say. When those flammable gasses - still way above auto-ignition temperatures - mix with atmospheric oxygen, the fireball begins. That cannot happen until some small distance beyond the muzzle.
Yep, that's exactly what happens. A mechanical flash suppressor works by diffusing the gas and mixing it quickly with air so it cools below the ignition point before there's time to make it burn. Some powder additives work to reduce flash by adding excess fuel that cools it; that works really well when there's enough gas expansion to make it cool enough to prevent afterignition at the muzzle, but when the same powder's used in a short barrel makes for huge fireballs. Additives like potassium sulfate work to delay autoignition, much like tetraethyllead used to in gasoline.

[zardoz]

I appreciate the ballistics analysis there on the fireball formation.

So I got a bit more curious, and wondered about slow powder in my S&W 629 with the 6" barrel.

These were 44 Magnums, 24.0 grains of H110 under a 240 grain lead SWC.

I shot some rounds with 11.0 grains of Unique after these, and no fireballs were found on the frame-by-frame video analysis. Just smoke trails.

Supporting your analysis, note the fireballs at a short distance from the muzzle. These chronographed fairly consistently at 1320 ft/s.

http://myfiero.com/uploads/17963_.jpg

http://myfiero.com/uploads/17962_.jpg

[August]

If you guys would add a little smoke, you'd have a black powder worthy situation.

I've read that Blue Dot has no flash suppressing components in its formulae. Some guys like to load it up in pistols and go to indoor ranges to terrorize the locals. Not me, of course.

[Rocky Raab]

Uh huh. Blue Dot is formulated to be a slow SHOTGUN powder, therefore no flash suppression needed or wanted. We metal-case shooters are "misusing" it!

Powders formulated for military or defense will almost always have a flash suppressant (potassium chloride, nitrate or sulfide). Examples are W231 and Accurate #9. Powders formulated for purely sport do not. The most egregious example is Power Pistol, which generates HUGE fireballs - even in daylight.

[Ricochet]

I don't think any of the common shotgun powders are made with a flash suppressant, and most pistol powders aren't. It's amazing to me how much of a flash you can get with the little powder charges in a .45 ACP or 9mm Luger.

[zardoz]

Well, now that I have a technique here developed, my mind is pondering all sorts of experiments with my current ammunition inventory.

I have some .40 S&W loaded with 8.0 grains Blue Dot under a 175 grain LSWC, and some .357 Magnums as well. 45 ACP loads with Power Pistol are in there somewhere.

I didn't figure Power Pistol to be a "big fireball" powder, but will check that one out with some 9mm I have loaded with 6.2 grains under a 105 grain LSWC.

I also have some .380 Auto loaded with Blue Dot and Power Pistol. I don't want the lose the brass on those, so I will have to figure out a way to shoot the video inside the screen tent. I'll figure out something.

This weekend is done, so maybe the next. The work week looms, and no time for such pursuits on the Monday-Friday salt mine duty. [smilie=b:

[AZ-Stew]

Here's a much larger and even more dramatic example of the fireball not forming until well downrange...

http://i27.photobucket.com/albums/c170/RockyRaab/USSidahookinawa1april1945.jpg

This photo was shot after most of the fireball had dissipated. I have a shot hanging on the wall in my office that shows the entire fireball from a 16" gun (all 3 guns in the turret fired almost simultaneously) where the fireball engulfs the muzzle, as well as extending a couple hundred feet off the beam of the ship. It all depends on when you trip the shutter. The only way to show the entire fireball in detail is to use a high-speed camera that takes hundreds or thousands of frames per second.

Regards,

Stew

[Rocky Raab]

Stew, this is one frame from a film, and until this frame, there was no fireball. It formed here and spread BACK to the muzzle in about three frames of standard 16mm film.

High-speed films show the following, pretty much in the same order every time: A jet of gas erupts from the muzzle (this is a combination of the air that was in the bore and some powder gas blowby). Then the bullet emerges. A cloud of gas emerges from behind the bullet and often jets around and past the bullet. The gas cloud expands in a turbulent way (presumably mixing with air), and THEN parts of the gas cloud burst into flame. The whole gas ball may or may not flash.

What is NEVER seen is flame preceding or immediately following the bullet. Always dark or clear gasses. A small ball of incandescent gas can often be seen right at the muzzle - and sometimes glowing embers/sparks are ejected also.

[Ricochet]

I suspect that those sparks are often what ignites the gases after mixing with air.

[Rocky Raab]

Undoubtedly. But the gasses alone are also way above ignition temperature, normally. Those anti-flash ingredients (possibly) work by reducing the gas temperature, but nobody knows for sure. They do increase smoke and reduce performance, though.

Here's what they say about it in a long article on Wikipedia:

"Nitrocellulose contains insufficient oxygen to completely oxidize its carbon and hydrogen. The oxygen deficit is increased by addition of graphite and organic stabilizers. Products of combustion within the gun barrel include flammable gasses like hydrogen and carbon monoxide. At high temperature, these flammable gasses will ignite when turbulently mixed with atmospheric oxygen beyond the muzzle of the gun. During night engagements the flash produced by ignition can reveal the location of the gun to enemy forces and cause temporary night-blindness among the gun crew by photo-bleaching visual purple. Flash suppression was attempted by structural modification of the muzzle of small arms. This approach was less successful for artillery, where a flame extending 150 feet (50 meters) from the muzzle might be reflected off clouds and be visible for distances up to 30 miles (50 kilometers).[37]

Flash suppression was achieved by smokeless powder additives. Cooler burning explosives like nitroguanidine or ammonium nitrate were added to reduce the temperature of combustion gasses. Inorganic salts like potassium chloride were added so their specific heat capacity might reduce the temperature of combustion gasses and their finely divided particulate smoke might block visible wavelengths of radiant energy of combustion. [27]"

[lurch]

the Fireball outside of the barrel is Wasted Energy. How about if you added a bit of oxidiser to the powder to help it accelerate the burn time while still in the barrell?


Or delay the load acceleration time to accomidate the power burn?

This is where a Sabot with shock absorber may work.[smilie=b:

A lot of powders burn plenty hot already and adding an oxidizer would only make it hotter with resultant consequences on things like throat erosion. How bad would it be? Don't know. Not sure I want to be the guinea pig though. You'd probably use less powder, but the time*temperature (i.e. energy dumped into the barrel steel) would probably be a good bit higher.

All hypothetically speaking of course...

[corvette8n]

OK whos gonna honcho the mold for this baby, I don't think I have enough lead on hand. I think Lee would have a 15 year wait on this baby lol

http://i27.photobucket.com/albums/c170/RockyRaab/USSidahookinawa1april1945.jpg[/QUOTE]

[Rocky Raab]

Lurch is correct. If smokeless powder didn't burn "rich" you'd possibly have a barrel life of one shot.

There's no free lunch with chemistry and physics. You can engineer to maximize anything you like - but at the expense of at least one other thing.


Corvette, that mould is available. It's a set of handles attached to a pony keg. LOL!

[Ricochet]

Undoubtedly. But the gasses alone are also way above ignition temperature, normally. Those anti-flash ingredients (possibly) work by reducing the gas temperature, but nobody knows for sure. They do increase smoke and reduce performance, though.
Cooler burning energetic compounds and excess fuels like dibutyl phthalate work by cooling the gases. The other additives like potassium salts have been well studied in suppressing detonation in spark ignition engines, which is a directly analogous autoignition of gaseous fuel-air mixtures heated well above the spontaneous ignition temperature. They suppress chain-branching free radical reactions in the preflame phase of combustion, slowing autoignition. I've lent out my copy of Explosion and Combustion Processes in Gases (Wilhelm Jost), else I'd look up some references for you. I highly recommend that book, if you can find a copy!

[Rocky Raab]

Thank you, brother ricochet. That's MOST informative.

The book would be WAY above the head of this English Lit major, I'm sure. I'm not a scientist, but I did interpret for them on TV a few thousand times. And that's true!

[Ricochet]

Interpreting on the fly and getting it right is a real talent!

[SciFiJim]

OK whos gonna honcho the mold for this baby, I don't think I have enough lead on hand.
When I was in Navy there were only two battleships left in commission and I never set foot on either one. Just what ARE the rounds made of? I know that they shot some sabots of depleted uranium, but what were the main rounds composed of?

[Rocky Raab]

If I recall correctly, the shells for the 16-inch guns were very much like 2,000-pound bombs: steel case, fuse and explosive inside. The differences were that the shells didn't have fins but did have copper driving bands.

I don't think the 16-inchers ever had either depleted uranium or sabot rounds. The 30-mm cannon on the A-10 attack jet uses DU rounds, and the Abrahms M-1 tank uses discarding sabots with a steel or DP penetrator rod. Both are for anti-armor.

[felix]

Correct, guys! The sulfate of either K or Na "slows" reactions, and is used extensively in film developers for this reason, and sent to "jungle" climates where they are typically used. Yes, the 16 incher "boolit", with that funny gas check around the side of it, is 6 feet tall. The ring is a little more than a fist as measured by me. USS Alabama in Mobile. The projectile is a bore rider, above and below the bearing. Somewhere around a foot or a little less for the below section. What is amazing is the fact that the barrel is micro-groove, with triangular lands (no flat anywhere). Looks like an inch from top to bottom of the "land". ... felix

[twotrees]

The standard Shell for the 16 inch gun weighed 2400 lbs and sounded like giant mad bee as it went over. (Nam). The gun was fired with Holly Black with a grain size about 1 inch in dia, packed in cloth bags.

Think of launching a VW Bug 21 miles and calling your shot. Thats how good they were. A good friend was a Forward Naval observer, and I still look up to him as a true hero.

Back to topic, I loaded some 223 ammo with some CMR 100 surplus powder, and fired a night coyote match. Well I fired the first 5 shots out of my 18 inch AR. I could Not see afterward, talk about flash blind. That powder was surplus, as it failed the flash suppression test. It shot really well in daylight and that was the first time I had tried it at night. Bright White fireball 2 ft in dia. at every shot.

I finished the match with some loads with 2015 and all was well, lost, missed shots 2-5, but still finished Ok in the standings.

Good Shooting,

[Ricochet]

The standard Shell for the 16 inch gun weighed 2400 lbs and sounded like giant mad bee as it went over. (Nam). The gun was fired with Holly Black with a grain size about 1 inch in dia, packed in cloth bags.
The first pad on the breech end was black powder, for ready ignition. The other bags were filled with extruded smokeless powder, the kernels having 7 holes in them that make them progressive burning as the surface area increases as they burn. (Until the growing holes meet and leave only the "splinters" in the corners between them.) The individual powder kernels are comparable in size to D cells.

Black powder as part of the charge reduces the muzzle flash from smokeless. The potassium salt effects we discussed earlier. The French used to load bags of cream of tartar (potassium tartrate) and wine dregs to inhibit flash.

[AZ-Stew]

There were two different shells for the 16 inch guns. One weighed 2400 pounds and was called a High Capacity round. Relatively thin skin over a LARGE charge of explosive. This is the main shore bombardment (gunfire support in Navy parlance) round. 16" diameter, about 5.5 feet long. It had, if I recall, detonation fuses in both the nose and base.

The other projectile was of about the same dimensions, but weighed 2700 lb. It had a thin metal ogive (called a windshield) over a smaller radius, pointed ogive, that was a very thick nose for the projectile. The windshield was for the purpose of increasing ballistic coefficient. The explosive charge was 1/3 - 1/2 the volume of the Hi Cap and it had a base fuse. It was what was called an Armor Piercing round, for ship-to-ship combat. The base fuse was designed to allow the projectile to penetrate up to about 16 inches of armor before exploding.

Ricochet is really close on the propellant charge. My training in Gunner's Mate School said the smokeless powder kernels were about the size of one's thumb. They were stacked in silk bags that weighed 100 pounds each. One end of each bag had a quilted pad that contained black powder, which is easy to ignite. The "primer" is approximately a .45-70 blank that is inserted into the breach block (from the outside) before firing. A powder charge for one round consists of six (yes, 6) bags of powder. The Iowa class battleships had, as described above, a sort of Micro-Groove rifling, but it was rectangular in cross section. The barrel was cast, but with a machined liner. The liner lengthened slightly with each firing. After a given number of rounds were fired, the worn and stretched liner could be replaced during overhaul.

Copper driving bands are used on rounds down to as small as 20mm. As noted, the remainder of the projectile is a bore rider. The copper band is for the purposes of sealing the bore and engaging the rifling. It is what causes the round to spin.

One of my GM school instructors told us that during the war when a couple of battleships were tied up in port next to each other, the gun crews would select the smallest man in the crew and have barrel races, with the guys crawling through the barrels. He didn't mention how they avoided being cut up by the rifling. May have been a BS story.

BTW, the larger guns are mounted in Turrets (8, 12, 16 inch), while the 3 and 5 inch guns are in Mounts. The difference is that guns in turrets can be elevated independently, while multiple barrels in a mount elevate together.

Rocky, I'm going to get out my Victory At Sea DVDs and watch the muzzle flashes to see if any of them progress backward to the muzzle. I never paid any attention before. If I think of it, I'll get my wall hanger scanned and post it here. You can see all three projectiles near the edge of the frame.

Regards,

Stew

[Rocky Raab]

Thanks for filling in the ammo details for this non-Navy guy. As a Forward Air Controller, I was taught the quite different terminology and procedures for naval versus army artillery adjustment, but we were only to direct naval gunfire in an emergency unless we had a naval observer aboard. I worked army artillery a bit, but never did work naval. Probably a good thing, as the terms were so different and confusion is a bad thing when large chunks of explosives are being hurled your way! Controlling airstrikes, adjusting artillery and working naval gunfire required THREE distinctly different methods and vocabulary - and there were times when you'd be using two of them at a time while you were flying right over the target!

To place that back on topic, screwing it up was a very effective way to BE a fireball.

[zardoz]

The blessed weekend is here, and it is a three day respite.

This time, I did two loads. Both 357 Magnum. I didn't catch any fireballs with 10.6 grains of Blue Dot, and it seemed as if this load with a 158 grain cast boolit gives me the better velocity out of my Taurus 606. 2 1/2" barrel, with six ports around the front sight.

The second load, which was 16.0 grains of H110 under the same boolit, gave a little better results (if you count bright muzzle flash as "good").

The main thing I noticed is the bright fire line at the cylinder gap, and also "mini-fireballs" that seem to be ejecting from the compensator ports. I did this one close to sundown, hoping to get a better flame picture, but not so it seemed.

The second picture has the better bright fire line at the cylinder gap.

Here they are:

http://myfiero.com/uploads/18047_.jpg
http://myfiero.com/uploads/18048_.jpg

[Rocky Raab]

The cylinder gap is just about the point of maximum powder burning, and also the pressure peak in many 357 loads. The bulk of the sharp report is due to that very high-pressure gas release. Everything after that is tailoff, and combustion is essentially complete. If any powder has not burned by that point, it isn't going to, due to the rapidly dropping pressure and temperature. There is still considerable temp and pressure there, which is why the bullet keeps accelerating. But that pressure is dropping fast.

[Ricochet]

Back to the 16" gun propellant momentarily, the U.S.S. North Carolina (WWII battleship) is on display near Wilmington, NC, a bit north of where I'm sitting on the beach at the moment. They have displays of the two types of 16" projectile (as well as numerous others just standing around), and of the powder bags. They also have a display of a few of the individual powder kernels, which is where I got my D-cell comparison. They look about that size to me. I don't doubt that they've used different propellants at different times, perhaps with different deterrents or none. We can come up with several examples of handloading propellants with similar burning rates and applications, but very different kernel sizes and shapes. I wonder if any Ball type powders have been used in artillery above the 30mm size or so?

[Jim]

http://castboolits.gunloads.com/showthread.php?t=60984

[AZ-Stew]

Ricochet,

I've visited the North Carolina a couple of times. The first was in '84, the second was in '94. My first visit was in the company of several other Gunner's Mates. We were on 2 weeks Reserve training at Camp Lejeune and took one of our free weekend days to drive down to Wilmington just to see the ship. When the bunch of us climbed up into the aft turret, a scent graced our nostrils that is perfume to Gunner's Mates! Mil-F-1711! It's a hydraulic fluid used universally in naval ordnance. We all recognized it at the same time. On my second visit, in '94, with the entire family, they had drained out the hydraulic oil and de-scented the place. I was VERY disappointed! Must have been some whining-weenie visitors complaining the the turret "smelled bad" or something. Anyway, it destroyed the "ambiance" for the visiting Gunner's Mates.

I don't remember seeing the powder kernels on display. I remember seeing all the cleaning gear mounted on a piece of plywood somewhere on board the ship. The cleaning brush is a wooden cylinder with scrub brush-like bristles protruding from the sides. There is a rope attached to one end. The rope is passed through the bore from the breech, then wrapped around a motorized capstan on deck to draw it through the bore.

To my knowledge, 30mm is the max size cartridge for ball propellants. I know 3" and larger Naval guns used extruded powder. I can't find too much data on the 40mm guns, but the one reference I found lists a nitrocellulose-based powder, leading me to believe it's extruded.

My thumb is about the length of a D-cell, but it's not quite as big in diameter. I guess it depends on perception. If you're going to visit the North Carolina again on this trip, take a photo of the powder kernel, with something in the photo as a reference, such as a coin or bill and post it here. I'm sure everyone would enjoy it. I'd go myself, but it's too far to walk this weekend.

Regards,

Stew

[zardoz]

Back at it again.

Since I was doing semi-auto today, I ran the video through the wall of the screen tent that catches my brass. It turned out well, as I was hoping the autofocus would ignore the screening, and it did apparently.

First picture is a Kel-Tec P11, 9mm, with 6.2 grains Power Pistol under a 105 grain Lee SWC boolit. Pretty bright. This is a concealed carry gun more than anything, only fairly accurate for me.

Second picture is a Smith and Wesson SW990L, 40 S&W, shooting 175 grain Lee SWC, over 8.0 grains of Blue Dot. This load is very accurate, and I just stumbled upon it by luck. It outshoots any factory loading I have. Oh yes, it uses CCI small magnum primers. The fireball is not that big on that one though.

http://myfiero.com/uploads/18066_.jpg
http://myfiero.com/uploads/18067_.jpg

[Ricochet]

Got to drive home tomorrow. No return to the North Carolina on this trip. I've several times taken the kids up there, and several times down to Charleston to the Yorktown and associated vessels and displays at Patriot's Point. Great way to spend a day!