8 cm PAW 600 The PAW 600 ( " Panzerabwehrwerfer 600 " , officially designated 8H63 ) was a lightweight anti - tank gun that used the high - low pressure system to fire hollow charge warheads . It was used operationally by " Wehrmacht " in 1945 in small numbers . Only about 250 were produced before the war ' s end . None were reported to have seen combat . Background . By 1943 , the German army was faced with various problems with regards their existing anti - tank gun designs . They had started the war with the 3 . 7 cm Pak 36 , which had the advantage of being very light at 328 kg , so that it could be moved a reasonable distance by hand using only its own crew . By 1941 , this gun was inadequate ; it could not deal with the heaviest armoured Soviet and British tanks . Its replacement , the 5 cm Pak 38 offered better performance ( though still only marginal against the new threat ) but , at 1 , 000 kg , was at the absolute limit of what the gun ' s own crew could effectively move into and out of a firing position by hand . The next gun , the 7 . 5 cm Pak 40 , was a very effective tank - killer ; but , at 1 , 425 kg , was no longer suitable for use by the infantry . A much larger crew and a vehicle was required to move this gun any distance at all and often just to displace it out of its firing position . Many were lost intact simply because they were overrun before their crews could move them . As the guns got bigger to deal with the latest tank technology and became too heavy for tactical employment , they also became more expensive . The PAK 36 cost RM 5 , 730 and 900 work - hours , while a PAK 40 cost RM 12 , 000 and took 2 , 000 work - hours to build . The situation was so bad that , by May 1944 , the 14th ( " Panzerjager " ) Kompanie of infantry regiments were having their heavy anti - tank guns removed and replaced by the " Panzerschreck " rocket launcher . But with an effective range of only 150 meters , this weapon did not provide the depth of fire required for the regiment ' s anti - tank defense . The only other alternative for a light anti - tank gun had been recoilless weapons , but the German Army was less than enthusiastic because this type of weapons has many shortcomings , particularly a high demand for propellant . Design and development . In 1943 , a specification was issued for a lightweight anti - tank gun that used less propellant than a rocket or recoilless weapon , yet was sufficiently accurate to hit a 1 - meter square target at 750 meters range . Rheinmetall - Borsig proposed a design to meet this requirement using the new high - low pressure ballistic principle , also known as the Hoch - Niederdruck system . In this system , high pressure caused by the combustion of the propellant was confined to the breech section , which was relatively heavy , and did not act directly on the projectile . It was allowed to bleed gradually into the barrel at a controlled rate and lower pressure to propel the projectile . Thus the barrel could be exceptionally light in a weapon that still had the advantages which accrue from high pressure . The carriage too could be very light , although initial prototype carriages proved to be too light and had to be redesigned . The resulting PAW 600 ( later redesignated 8H63 ) gun weighed about 600 kg , less than half that of the 7 , 5 cm Pak 40 while having comparable armor penetration out to its full effective anti - tank range of 750 meters . Unlike previous anti - tank guns , which relied on firing steel projectiles at high velocities to penetrate heavy armor , the 8H63 was designed to fire shaped charge ammunition ( called also hollow - charge ammunition , high explosive anti - tank , or HEAT ) . Because shaped charge warheads perform best when no spin is imparted on the projectile , the 8H63 was a smoothbore design . To simplify development and manufacture , the projectiles used were based on the widely used 8 cm Granatwerfer 34 mortar ( actual caliber 81 . 4 mm ) . This allowed the use of existing tooling in the manufacture of ammunition , which reduced the costs . The cartridge case was developed from the 10 . 5 cm leFH 18 howitzer . The standard shaped charge projectile designated 8 cm W Gr Patr H1 4462 weighed 2 . 70 kg . The propelling charge was 360 gm of Digl B1 P ( compared to a 3 . 8 kg propelling charge in a PAK 40 ) and with a muzzle velocity of 520 mps this had an effective range of 750 meters against a tank - sized target . Armor penetration was 140mm of vertical armor , which was comparable to the 7 . 5 cm PAK 40 firing the rare and expensive tungsten - cored AP40 shot . Other uses and rounds . Because the ammunition was developed from the standard infantry mortar , any type of round developed for the mortar could have been readily adapted for the 8H63 , including high - explosive ( HE ) , smoke and illuminating rounds . The HE round , the 8 cm W Gr Patr 5071 with a 4 . 46 kg projectile and total round weight of 8 . 30 kg was developed . This could employ 3 different charge increments for maximum ranges of 3 , 400 meters @ 220 mps , 5 , 600 meters @ 320 mps or 6 , 200 meters at 420 mps - about 3 times farther than the mortar and with the possibility of direct or indirect fire . This performance brings up another interesting feature of this gun . Traditional high - velocity anti - tank gun s were very inefficient when employed as field artillery firing explosive rounds in support of the infantry . The thick projectile walls necessary to withstand high velocities ensured a small explosive payload and the amount of propellent used was wasteful . The guns also fired at low trajectories ( + 22 degrees for a PAK 40 ) which limited their utility . For this reason , the German Army had always employed Infantry Guns , such as the 7 . 5 cm leichtes Infanteriegeschütz 18 , at the regimental level to provide fire support under the direct and immediate control of the infantry . This meant every infantry regiment had an infantry gun company for use against unarmored targets and a tank destroyer ( anti - tank gun ) company for use against armored targets . The 8H63 , firing an explosive round had lethality comparable , if not superior , to the 7 . 5 cm infantry gun and much greater range . The 8H63 ' s multi - charge cartridge and + 32 degree elevation could have allowed the merger of the infantry and anti - tank gun categories with a resulting savings in production , logistics , and precious manpower . The 8H63 was to be organized under the new 1945 Table of Organization and Equipment ( TO & E ) in anti - tank companies of 12 guns with 104 men , replacing the anti - tank and infantry gun companies ( 300 + men ) of previous organizations . Production . Some 260 guns and 34 , 800 rounds of ammunition were completed from December 1944 , with 81 guns delivered to the troops in January 1945 and 155 listed on March 1 , 1945 . Plans had called for the production of 1 , 000 guns per 4 , 000 , 000 anti - tank and 800 , 000 explosive shells per month . Production models had either the purpose - built light carriage or used redundant PAK 38 carriages and PAK 40 muzzle brakes and were slightly heavier . Further development perspectives . Several self - propelled models were proposed in 1945 , but the war ended even before prototypes could be built . It is clear that , had the war in Europe carried on longer , the 8H63 would have been a major factor and would likely have replaced the towed PAK 40 and various 7 . 5 cm infantry guns in production . Krupp was also developing an enlarged 10 cm design known as the 10 cm PAW 1000 or 10H64 at the end of the war , but none reached production . This would have had an armor penetration increased to 200 mm in a gun of about 1 , 000 kg with the effective range against tanks increased to 1 , 000 meters . Nomenclature . The " Panzerabwehrwerfer 600 " ( " anti - tank thrower " ) designation was used by Rheinmetall during the design phase . The service designation was 8H63 in accordance to the new designation system used during the last year of the war . In 1944 - 5 , the Germans changed their system of artillery designations from the old " year " system . Each weapon was to have a number showing their caliber group , a letter denoting ammunition group , and the last two digits were from the weapon drawing number . In this case , 8 denoted 81 . 4 mm caliber using the H group of ammunition . The shells were all to be designated as H with a 4 digit number , the first three were the drawing number and the last was the shell ' s category from the following list :