2-BORE GUN, VRIJEDNO SPOMENUTI NA FORUMU

[jolly]

Vrijedno spomena na ovom cijenjenom forumu.
Prema ovome, 700 Nitro Express je za bebe.

2 Bore dolazi od stare engleske mjere kojom se i danas mjeri promjer cijevi sacmarice, pa imamo 12 bore (gauge), 16 bore (gauge) itd.

2 bore znaci, da bi promjer cijevi trebao biti takav da prolazi kugla olova tezine 0.5 founte (Lbs).
Po tome ispada da je 2 bore, promjer cijevi od 1,352 incha, za kuglu olova takve tezine. Sto iznosi 34,34 mm.


Medjutim, konstruktor je isao na obik konusnog zrna za metak (tezine pola funte), a konusno zrno je izduzeno, dakle promjer cijevi je prilagodjen za oblik konusnog zrna, tezine 1/2 funte. Onda promjer cijevi u gotovoj puski iznosi 1.052 incha, to jest 26.072 mm.

Entuzijasti za magnume mogu biti malo razocarani, jer je puska konstruirana za metak na CRNI BARUT, ali svakako inpresivne snage i TRZAJA.
Cijena jednog metka radjenog po narudzbi je oko 100 USD, ekvivalent cijene drugog najskupljeg metka na svijetu, 700NE.
Postoji doduse, mogucnost punjenja metka bezdimnim barutom, za koji zacudo kazu da smanjuje trzaj?!

Medjutim, cijevi se mogu naruciti uzljebljene za klasicni metak, glatke za sacmu, i glatke za HARPOON! (prema uzoru na oruzje za lov kitova)

Puska ima potraznju, i narucuju je ljudi koji misle da im to treba.
Nije mi poznato da je to neko nosio na prakticni safari u Afriku.

Za 2Bore gun, Koristena je FALLING BLOCK AKCIJA, jedna od najcvrscih ikad konstruiranih, patent iz 19 stoljeca.

Moderni entuzijasti mogu naci nesto slicno kod serijeske tvornicke puske Ruger no 1,
Ruger no 1 se svake godine proizvodi u seriji od nekoliko drugih razlicith kalibara nego prethodnih serija, i pokriva najjace lovne kalibre, pa sve do najslabijih, kroz godine proizvodnje mijenjajuci kalibre, Ruger no1 pokrio je nevejerojatan spektar lovnih kalibara.
(RUger No 1, baziran je na Farquharson mehanizmu), i dosta je jeftinija od ove puske iz naslova.

Detaljni opis puske 2 bore gun dao je casopis FIREARM NEWS.
https://www.firearmsnews.com/editorial/ ... fle/365185

Slike u nastavku iz istog casopisa, i cijeli text nek ostane zapisan na forumu ako casopis povuce text s interneneta.

[jolly]

The Tyrannosaurus 2-Bore: Most Powerful Sporting Rifle
Since the 2 bore is the most powerful sporting rifle ever made, it is only fitting that it would honor the most powerful predator of all time, the Tyrannosaurus Rex.

By Jim Dickson
Since the first announcement of the availability of a monstrous, 2 bore rifle in the 2010 Gun Digest, British Best Quality gun maker Giles Whittome has been turning out a steady stream of them as fast as he can make them. Some of these have gone to Russia. The Russians can be very secretive. We know they have been trying to clone the wooly mammoth. Kinda makes you wonder just what HAVE they brought back.

Giles Whittome is the only man to ever have fired a 24-dram load with a 2500-grain slug, and he says he will never do that again. At this point, the recoil has become dangerous to the shooter. Giles was shooting at the Queen’s estate at Sandringham at the time, and fired it into a two-foot by two-foot block of seasoned English oak that axes bounced off. One shot reduced it to kindling, to everyone’s amazement. Small wonder, since that is eight times the powder charge and 5.75 times the bullet weight of a standard 12 bore (12 Gauge) Brenneke slug.

This particular gun weighs in at 27 pounds and has proved capable of putting all its bullets in one hole at 50 yards. This three-shot group was fired by a giant Scotsman who has been described as a grizzly bear built like a Sherman tank. You would never shoot anything requiring a 2 bore at ranges past that.

Why would you want such an enormous gun? When Giles was doing culling work for the Elephant Control Division of the Tanganyika Game Department, they used to say, “When 5 or 6 tons of angry pachyderm is coming at you at 25 MPH, whatever you hold will seem far too small.” That’s when you REALLY want a 2 bore. Being suddenly ambushed by a cape buffalo that someone else wounded and you had no idea was there is another good reason. These things happen in Africa, and they happen at close range and with no notice.

What will a gun this size do on game? Well, the famous 19th Century African explorer, Sir Samuel Baker had a famous 2 bore muzzle loader that he loaded with a half-pound explosive shell. He once blew up a buffalo with one shot from it at 600 yards. Baker’s gun was made by Holland and Holland in 1869, and was serial number 1526. It was actually an underweight, 18-pound 4 bore shooting a half-pound explosive shell backed by either 10 or 12 drams of powder. At that weight, it kicked so viciously that Baker said it spun him around like a weathercock every time he fired it, but it never failed to make a one-shot kill. Baker named it “Baby,” but his Arabs called it “Child of the cannon.” If Baker had told Holland and Holland to make it weigh 50 pounds when he ordered it, he would have had a much more pleasant time shooting this beast. When you have a gun bearer, the extra weight is not so much of a problem.

[jolly]

The complete details of making the Victorian hunter’s explosive shells have never been published to my know-ledge, so here they are. The use of explosive bullets was a development of Lieutenant Forsyth of the Bengal Army in India. It turned the heavy 8- and 4-gauge rifles into proper artillery pieces for the ultimate in close-range stopping power in the close confines of the Indian jungle, where ranges were often measured in feet instead of yards. The formula is for a high-explosive compound, not a low-explosive. It consists of equal parts by weight of potassium chlorate (chlorate of potash) and antimony sulfide (black antimony or laminated sulfurette of antimony).

These two ingredients must be very well mixed with a WOODEN spoon in a WOODEN bowl, with nothing metallic in contact with them at any stage. The mixture is put inside a two-part bullet. There is one bullet mold for the bottom part, and another bullet mold for the top part. A screw swage forces the two halves together with the explosive compound in the center core, and sizes it to the correct groove diameter. The swaged joint doesn’t usually break at the explosion—the bullet usually fragments. It is made with such thick sides that it needs bone to set it off, so it doesn’t explode on the surface. This mixture explodes through compression and percussion together (it must be confined and hit). It does not need ignition by fire.

This is the only successful exploding hunting bullet because of its precisely tuned exploding properties. It gave new meaning to the term “Blowing an elephant’s brains out” in its day. Giles Whittome will gladly make a set of loading tools and molds for these shells to your rifle’s bore diameter.
To calculate the power of the 2 bore, we use Taylor’s knock-out formula: bullet weight in grains multiplied by velocity in feet per second, multiplied by bullet diameter in inches, divided by 7,000 (because there are 7,000 grains to a pound). This has proved to be the most reliable formula for showing a cartridge’s effectiveness on game. By this formula, a .375 H&H magnum has 40 knock-out values, a .600 nitro express has 155, and the 2 bore with a 2,500-grain bullet has 544. The colossal 2 bore certainly makes a .600 nitro express look puny by comparison.

The common bullet energy formula for foot pounds of muzzle energy is bullet weight in grains multiplied by muzzle velocity squared, divided by 450,240. This bears little relationship to a cartridge’s effectiveness on dangerous big game, because velocity is too big a part of the equation, where bullet weight and frontal area are much more important in real life. Blind belief in this formula resulted in a neat row of tombstones in Nairobi, of hunters in the 1920s, who read that the .280 Halger had the muzzle energy of the .577 nitro express, by this formula, and foolishly used it on big game. By this formula, the .375 H&H magnum 300 grain at 2,350 FPS (which was banned for use on dangerous game in multiple African countries), has 4,165 foot pounds of energy, the .600 nitro 900 grain bullet at 1950 FPS has 7,600 foot pounds of energy, and the 2 bore with a 2,500 grain bullet at 1,450 FPS has 11,675 foot pounds of energy. No matter how you compute it, the 2 bore comes out the champ.

True cannons begin with 4 bores, as this is the size of most swivel cannons. Anything larger tended to break out of the mounting on a ship’s rail. Giles Whittome’s 2 bore rifle is twice that size. The cartridges are all hand-made and cost $100 apiece. They can also be made loaded with smokeless powder, and that does reduce the recoil.

When the Royal Armouries in England ordered the first 2 bore rifle, they sent Giles Whittome into uncharted waters, for there had never been a 2 bore rifle and very few 2 bore shotguns. The last one made was a muzzleloader proofed in 1917. Giles had to make up a new 2 bore proof stamp for the proof house for this one. When proof fired, the whole building shook, and even with the fans going, it was an hour before the smoke cleared enough to go into the room. This was proof firing a cannon in every sense of the word.

Once you get past 8 gauge, the sheer bore size needed to fire a true round ball led British gun makers to reduce the bore size and go to conical bullets, which penetrated better than the round balls. Thus, a 4 bore is .935" instead of 1.052", which it would require for a quarter-pound round ball. They are actually proofed as a 6 gauge, which would be .919", but since it shoots a quarter-pound conical, they are stamped 4 gauge at the proof house. The 2 bore would need a 1.325" bore diameter for a half-pound round ball, but that makes for a barrel of about 30 pounds, according to length, so conical bullets are used and the bore diameter is 1.052", which is actually true 4 bore size. Confused yet? Of course, this also lets you shoot true 4 bore round balls as a light load in the 2 bore if you want. That’s the first time a 4 bore, which has 300 foot pounds of recoil in a standard 4 bore rifle, has ever been called a light load.

After the death of the engraver who worked on the previous 2 bore guns, Giles has used a new continental artist with unusual skill with semi-Celtic-style engraving, and it can be seen how well he copes with the difficult art of matte-finishing the background for contrast. The green-gold inlays are of Tyrannosaurus Rex with prehistoric ferns in the background. A saurian eye glares at you from the top of the action, or Knox form of the action, to use an old gun-making term.

The stock is the finest piece of Circassian walnut that the maker has seen in 60 years of gun making, and it cost Giles accordingly. Due to the massive size, the blank has to be 2.5 inches thick. For a gun with this much recoil, the grain of the wood must run straight through the grip (the thinnest part of the stock), or it may well split with the tremendous recoil. The grain then branches out into the magnificent patterning seen towards the butt. The stock is fitted with a leather-covered Sorbothane recoil pad. There is no checkering on the stock, because with this recoil level, checkering would strip the skin from the shooter’s hand. Remember, this is the heaviest-kicking gun ever made. It is capable of firing loads with heavy enough recoil to kill the shooter. That’s why the standard load is kept where it is. It’s worth noting that no one but 6' 5" Giles, the giant Scot, and the purchasers of the guns have ever been willing to fire it more than once. Giles doesn’t stand behind people firing it to catch them, if need be, for nothing. This brings up another advantage of the 2 bore. One of the hardest jobs in Africa can be finding a gun bearer that will not shoot the gun himself instead of handing it to you in a tight spot. The 2 bore solves this problem eloquently. Simply have him fire it once. This requires two men in attendance, one to catch the gun and one to catch the gun bearer as they go through the air. From then on, he will have no temptation to fire the gun in a tight spot, and you can depend on it remaining loaded for you alone to fire. Giles has noticed with amusement that the average order for shells with a gun order is 30 cartridges, and there have been no orders for more shells.

[jolly]

A mammoth gun like the 2 bore requires proper form when firing to prevent injury. Lean into the gun, and let it push you upright with the recoil. If you try to stand up straight, you haven’t enough room to go backwards without falling. Do not brace against the gun and fight the recoil—it can injure you if you do. Hold the gun snugly against the shoulder, but not so tight that the tissue has no room to compress under recoil, and now relax as you fire. You have to relax and roll with the punch. That’s the only way to handle any massive kicker, and this is the champion kicker. If you relax and just let it push you upright, you won’t get hurt. Be sure to have a tight grip on the gun so it won’t fly out of your hands.

The falling block action is copied from an old Alexander Henry harpoon gun in the Tower of London Armouries. Giles offered to restore the gun for them if he could take its measurements, and they quickly accepted the offer. The result is a classic 19th Century big-game rifle on a grander scale than any before it. The lock is a regular outside hammer 4 bore lock. The non-rebounding hammer’s nose goes into the falling block to strike the recessed firing pin and serves to further lock the falling block in place at the moment of firing. The hammer has the traditional half-cock notch for loading and carrying. There is a push-button release button on the falling block lever, so you never have to worry about recoil bouncing the falling block down.

Should you wish to shoot whales with a harpoon, Giles will make you a smooth-bore version and supply any harpoons and bomb lances required. You cannot launch harpoons out of a rifled barrel, because the rifling twist will spin the harpoon, which will twist its rope. Effectiveness on game will not be diminished, as you don’t shoot anything big enough to need a 2 bore at ranges beyond the accurate range of a smooth bore.
A smooth-bore 2 bore loaded with buckshot would also be devastating to hyenas prowling around the camp after dark. If big grizzlies are your late-night visitors, the 2 bore enables you to use much bigger diameter balls than standard buckshot sizes and still have an acceptable number of projectiles in your pattern.

As of this time, no Americans have fired the 2 bore rifle, only Englishmen, Scotsmen, and Russians. It’s a shame that no American with deep pockets has bought and fired one, leaving the glory of handling this brute to the aforementioned nations. It galls me to think of the Russian owner of a 2 bore saying “Amerikantsy slishkom slaby, chtoby vladet’ I strelyat’ iz etoy vintovki.” (Translation: “Americans are too weak to own and fire a rifle like this.”)

[jolly]

Iako danas ovakav kalibar 2-bore, 1 + inch, zvuci monstruozno, medjutim treba treba naglasiti da je ovo sve u skladu prilagodbe starome sistemu i balistici crnog baruta.
Na primjer stara Britanska kolonijalna musketa Brown Bess, glatke cijevi, paljenje na kremen, za trupno gadjanje u liniji bila je kalibra (ili bore-a) 0.75 inch.
Dok se kalibar 45 ili 50, vec smatrao varmint calibrom u to doba, tzv "squirel gun", puska za vjeverice.

Dakle, ni ovo nije toliki novitet.

[Barut]

Zanimljiva naprava.

Malo je to konfuzno vezano za kalibar, ali u stvari se radi o puški u kalibru 4 promjera cijevi 1.052" ili 26.7mm, samo što puca zrna čija težina odgovara kugli od olova koja bi stala u cijev kalibra 2.

Svojevremeno, kada sam bio zagrijan za velike kalibre , sam dosta pucao iz takve puške cal.4 s glatkom cijevi, i sa crnim i sa nitro barutom. Naravno moja nije ništa takvo fensi ko ova $$$$ na slikama, nego "budget" verzija koju je proizveo BRNO 80-tih. Osim toga, pušku tako velikog kalibra su napravili i Rusi i poznata je pod nazivom KS-23. Ta puška je nastala kada su u Rusiji imali višak cijevi za svoje topove kalibra 23mm, pa su ih odlučili iskoristiti i napraviti seriju pušaka u tom kalibru. KS-23 je korištena u vojno policijske svrhe, a ispucavala je sačmu, projektile sa suzavcem, flash-bang i signalne patrone i slično. Kasnije je TOZ proizveo i civilnu varijantu s nazivom TOZ-123. Puške su u osnovi iste, obje su pumperice sa spremnikom od 3 metka. Razlika je što KS-23 ima užlijebljenu cijev, a TOZ-123 glatku, a obje su promjera 23mm što ih svrstava u kalibar 6, iako ih neki (pa i sam TOZ) nazivaju kao puške kalibra 4.
https://wiki2.org/en/Gauge_(firearms)

[jolly]

Big bore guns, imaju svoj sarm.
To sam skuzio, nakon sta sam nabavio 375 HH.Inace big bore pocinje iznad 0.40 u kalibru
To je blizu pravog "big bore", ali nije usao u ovu definiciju, ali gusta me trenirati tom puskom na strelistu.
458 win mag mi tako onda nekako postaje simpatican.
Kao i svi kalibri iznad tog u expresicama.
Naravno, ne planiram kupovati tako nesto, ali volio bih isprobati. U medjuvremenu, kad je prilika, ispalim s gustom po koji u metu iz 375 HH.

[nijoe]

Dobra stvar kod tih čuda je što ti drugi hitac taman namjesti nazad isčašeno rame nakon prvog.

[jolly]

Pogotovo ako pucas malo iz lijevog, malo iz desnog ramena pa se kompenzira!

[Darko11]

Zanimljivo.Oko 23 000 Joula energija na ustima cijevi.Solidno.

Usporedba 2 bore cahure i 45-70
https://en.wikipedia.org/wiki/2_bore#/m ... tridge.jpg

Jedino pitanje je, cemu bi ovo cudo moglo sluziti osim cistog entuzijazma i uzitka na streljani?

[nijoe]

Pa za lov na divljač iz razdoblja triasa i jure, već za ledeno doba je malo prejak.

[jolly]

Zanimljivo.Oko 23 000 Joula energija na ustima cijevi.Solidno.

Usporedba 2 bore cahure i 45-70
https://en.wikipedia.org/wiki/2_bore#/m ... tridge.jpg

Jedino pitanje je, cemu bi ovo cudo moglo sluziti osim cistog entuzijazma i uzitka na streljani?

Darko, ja se tebi cudim!
Pa protutenkovska upotreba!

Osobno mislim da je ucinkovistos velikog kalibra na najevecoj divljaci diskutabilna, mozda pri granici .577 NE.
Sa 470 NE, imas vec sve sta se moze traziti. Kod velikih kalibara, sirokog promjera, dolazi probojnost u pitanje zbog sirine i frontalne povrsine zrna, ovo se kompenizra punjenjem i energijom, , a ovo pak rezultira trzajem, a trzaj sa vecom tezinom puske, pa se postavlja pitanje zasto? Mozda shokirajuci efekt, prema tayloru, knock out value, ali to smo raspravljali i sporili.