GC - 45 howitzer The GC - 45 ( " Gun , Canada , 45 - calibre " ) is a 155 mm howitzer designed by Gerald Bull ' s Space Research Corporation ( SRC ) in the 1970s . Versions were produced by a number of companies during the 1980s , notably in Austria and South Africa . The most publicized use of the design was in Iraq , where the GHN - 45 variant used by some Iraqi artillery units had a longer range than any coalition artillery . This initially caused considerable worry on the part of the allied forces in the Persian Gulf War . Design history . The GC - 45 ' s general design followed several decades of work by Bull with fin - stabilized artillery shells , starting at the Canadian Armament Research and Development Establishment ( CARDE ) and later at Project HARP . In these efforts accuracy was not a huge concern , the objective was muzzle velocity , and the test articles were finned darts representing missiles . Yet with the removal of the rifling and the soft - metal driving band on the shell itself , the shell could be designed purely for ballistics , as opposed to having the external constraint of the driving band . A system combining some sort of rifling for accuracy without a driving band would result in a longer - range weapon . However , such a design was never achieved . After years of research at his Quebec firing range , Bull eventually settled on a solution . The resulting Extended Range , Full Bore ( ERFB ) ammunition was key to SRC ' s designs : a " pointy " looking shell with much lower drag at supersonic speeds . For longer range applications he added a base bleed system ( invented in Sweden ) that could be screwed onto the standard shell , as well as an even longer - ranged system with a rocket booster . The gun designed to fire it had a chamber , a 45 - calibre rifled barrel with 1 / 20 right hand twist fitted with a conventional muzzlebrake . Its breech was a conventional screw with interrupted thread . Key performance data , from the Firing Table are : The dispersion of the EFRB shell is more than three times that of the FH - 70 field howitzer at its maximum range of only 5 km less , and is twice as great as FH - 70s at . Its maximum range with the M107 projectile is the same as any 39 calibre 155 - mm gun and its dispersion about the same . ( The " dispersion " figure means that 50 % of shells will fall up to the stated distance either side of the mean point of impact , but 100 % will fall within 4 times the probable error either side . ) Dispersion of this magnitude significantly reduces the tactical value of the equipment . In 1977 , Bull ' s work put him in touch with ( what is today ) the Denel SOC Ltd company of South Africa . Denel designed a new mobile mounting that was able to handle the increased recoil . It used a sole - plate to lift the carriage to take the four wheels off the ground . The chassis had the option of being powered by a small diesel engine acting as an APU , driving hydraulics that could set up the gun in two minutes , and move it short distances . This feature had been previously been included in the 1960s design FH - 70 carriage by Vickers . Bull , meanwhile , started production of $ 30 million worth of rounds , shipping them via Spain to avoid the international arms embargo against South Africa . At first , the U . S . chose to overlook Bull ' s actions and , according to him , the CIA actively mediated the deal between Space Research and the South Africans . However , when the Carter administration joined the international efforts to sanction South Africa ' s apartheid regime , Bull was arrested by U . S . Customs agents in 1980 . The investigation did not go far , and active work on the case was ended by direct intervention of the White House . Bull pled guilty and was sentenced to a year in prison , serving six months . Having expected some sort of " slap on the wrist " , he was embittered and made statements to different newspapers that he would never set foot in North America again . He left Canada and moved to Brussels where he continued his work . Production . Denel ( then Armscorp ) continued work on their version of the gun , and these were put into service in South Africa in 1982 as the G5 . They started replacing a variety of older guns , such as locally - built World War II - era Ordnance QF 25 pounder s . The G5s saw service against Cuban and FAPLA forces in the Angolan conflict , where they were used very effectively . Noricum , the arms division of the Austrian steel company Voest - Alpine , purchased the design rights to the GC - 45 after SRC moved to Europe . They made a number of detail changes to improve mass production , resulting in the GHN - 45 ( gun , howitzer , Noricum ) , which was offered in a variety of options like the APU and fire control systems . The first foreign sale was an order for eighteen guns with ammunition to the Royal Thai Navy for use by their Marine Corps . Other " aboveboard " customers included China , Singapore and Israel . All of these companies worked on local production under a variety of names , the Soltam 845P in Israel , ODE FH - 88 from Singapore , and PLL01 / WA021 in China . Bull was soon contacted by Iraq , which was constantly being attacked by Iranian artillery during the Iran – Iraq War . Iraq placed a US $ 300 million contract for 110 guns from Noricum in Austria and 41 , 000 rounds subcontracted by SRC to PRB in Belgium . Deliveries were made in 1984 and 1985 . The number of guns was eventually raised to 200 . Iran and Iraq were under arms embargo at the time , so the guns were shipped to Jordan , and from there to Iraq . These sales led to the " Noricum affair " in 1990 , when eighteen of Noricum ' s managers were placed on trial for illegal arms sales . A further 100 guns were manufactured in South Africa . In Iraq the guns had a similar effect on the ongoing Iran – Iraq War as the G5 had in Angola , stopping any push by the Iranians deeper into Iraq . They became desperate to get more of these guns into the field as soon as possible , and requested that Bull improve deliveries any way he could . Bull then arranged a deal to deliver the G5 , which fired the same ammunition as the GHN - 45 , from South Africa . By the time of the Gulf War , about 124 of these weapons had been added to the Iraqi long - range artillery , supplanting their older 130 mm M - 46s and hodge - podge of other weapons . Bull and Saddam Hussein became partners in a number of future ventures . These ventures are generally believed to be the cause of Bull ' s assassination , for which the Israeli Mossad or Iranian agencies are the prime suspects . During the Gulf War , however , the GHN - 45s proved less effective than anticipated by either side . Air strikes had disrupted the Iraqi command and control facilities , and because most of their gun tractors had been withdrawn to serve with logistics units in an attempt to re - supply the front line troops , they were unable to withdraw when under fire . Immobile and unsupported , the majority of the guns were destroyed at their positions either by air strikes or Multiple Launch Rocket System s ( MLRS ) counter - battery fire . The Chinese People ' s Liberation Army also used the Noricum version , producing it as the PLL01 , which entered service in 1987 . They also mounted it on a locally - designed tracked chassis to produce the PLZ - 45 ( also known as the Type 88 ) , along with an ammo - carrier based on the same chassis . The PLZ - 45 did not enter service with the PLA primarily because their existing artillery was all based on Soviet - standard 152 mm ammunition . However , two major batches of PLZ - 45s were sold to the Kuwaiti Army in 1997 and 2001 , and to Saudi Arabia . Subsequent development . Bull continued work on the GC - 45 , producing a much more practical version known as the FGH - 155 . In addition to a number of detail changes and deeper rifling , the FGH - 155 allowed standard M107 ammunition to be fired using a plastic adaptor ring . Bull also felt that the FGH - 155 ' s carriage was suitable for a larger gun , and worked on the FGH - 203 , an 8 " ( 200 mm ) gun adapted from U . S . standards in a fashion similar to the original GC - 45 work . The increase in projectile weight gave the new weapon a range of over 50 , 000 meters with normal ERFB - BB ammunition , making it one of the longest - range artillery pieces in the world . The gun was also purchased by the Iraqis , who mounted it in a self - propelled form to create the Al - Fao . The Denel G5 version has also seen continued development . The gun has been placed on an OMC 6x6 chassis as the G6 howitzer , and won major export sales to the United Arab Emirates and Oman . In response to an Indian requirement , the G5 was mounted on a 4x4 truck , resulting in the T5 , though none had been ordered . It is also fitted into a turret that can fit on any suitable vehicle . The turret is marketed as the T6 which has already been fitted on the T - 72 . Denel also used the basic ERFB ammunition concept to develop a 105 mm gun , the G7 howitzer , which allows artillery to be downsized to improve mobility .