Defender1 | 17 Feb 2017 8:38 a.m. PST |
Can someone please, in the simplest of terms so I can hopefully understand it, what a ranging gun is/was and how they were used? I am afraid I do not grasp the concept. |
Murvihill | 17 Feb 2017 8:46 a.m. PST |
Basically it is a smaller caliber weapon that could be used to determine the range so you can shoot accurately with your big gun. For example, you'd fire a .50 MG until you are bracketing the target, then fire your 90mm (or whatever). Can't remember which tanks had them. Hopefully now one of the experts will weigh in. |
MadMax17 | 17 Feb 2017 8:55 a.m. PST |
Chieftains were the main ones in the 80s if I remember correctly. A similar concept applies to other weapon systems; for example in Bradleys without the LRF, the approved engagement method is 1 sensing round to confirm range, followed by a 3 round burst if the sensing was on. If not, keep firing sensing rounds until range is good. |
leidang | 17 Feb 2017 9:05 a.m. PST |
The Experimental US M6 Heavy Tank (1942) had a 37mm mounted in the coax position as a ranging gun next to the 76mm gun. As above the idea was to get the range with the smaller, easier to re-load gun before firing the heavier gun to make the kill. Obviously it's best if the ranging gun has similar ballistic characteristics to the main gun. |
Irish Marine | 17 Feb 2017 9:23 a.m. PST |
The 106mm recoiless rifle had a .50 cal spotting rifle alog side the barrel you fired the .50 then the 106. |
ScoutJock | 17 Feb 2017 9:26 a.m. PST |
The Israelis starting using after the 73 war, especially the .50 cal because they found the trajectory for the L7 105 mm sabot basically matched that of the .50 out to about 1800m. They would fire a tracer from the .50 cal and because it was slaved to the 105, they could get adjust the burst of the main gun quicker and with less depletion of main gun ammo. Or so I read someplace once. |
Kropotkin303 | 17 Feb 2017 9:55 a.m. PST |
The AMX30 has a 20mm gun right next to the main gun. Not sure if this was for the ranging or just a unique set up peculiar to this tank. |
nickinsomerset | 17 Feb 2017 9:59 a.m. PST |
Yep Chieftain had a ranging gun, fire 3 rounds at the target, if you see tracer impact, bang!! As a gunnery instructor used to say to us in Bovington, the worst thing a Soviet tank crew can here is tap, tap, tap!! Tally Ho! |
troopwo | 17 Feb 2017 10:25 a.m. PST |
Centurion and Chieftan tanks had a 0.50 cal in the gun mount, as well as the main gun and a 7.62mm for a coaxial mg. It works like as follows. The commander would order out. "Ranging HESH 1200 tank on" (He is starting off with the ranging mg, he intends to use a HSEH round, the estimated range is approximately 1200meters, and the the target is a tank and the turret and gun are now pointing close enough for the gunner should see the target) The gunner flips his selctor switch to the ranging gun, shouts back "1200" meaning he understands the estimated range and shouts, "On" when he sees the target on his own. The commander orders"Fire" The gunner fires and a three round burst of fifty cal trace rounds flies off. Everyone observes where they hit or land. If they hit, then the commander shouts out, "HESH go on" and the gunner fires off the main gun. If teh trace is short or high, the commander adjusts the range estimate appropriately. He can then fire off the main gun or if wildly innaccurate try another ranging burst. It is actually pretty fast. Only a laser range finder is faster these days, and not by very much time believe it or not. The only negative side is that it is active, meaning that it gives the position away. The fifty cal trace rounds were ballistically similar in flight trajectory as the 105mm HESH rounds. (800-900m/s) Similarly the later 120mm HESH rounds for Chieftan. The ranging gun was normally for the large caliber rounds like HESH. The APDS or sabot rounds have such a high velocity that there was very little dispersion at battle ranges up to 1500m. In the US HESH is the equivalent of HEP. |
BattleCaptain | 17 Feb 2017 11:31 a.m. PST |
Troopwo has it exact. As student tank officers on Centurions with ranging MGs, we spent hours practicing range estimation with the Mark 1 Eyeball, until we were accurate to within about 10% at any useful distance. It's one of several skills I mastered that have now been rendered obsolete by modern technology! |
Defender1 | 17 Feb 2017 12:58 p.m. PST |
Many thanks for the replies especially troopwo. I believe I understand now. |
emckinney | 17 Feb 2017 2:36 p.m. PST |
A .50 ranging gun also has much less flash, muzzle blast (smoke/dust) and sound than a 105mm. A hit that goes long is far less likely to be noticed. HESH/HEAT going long makes a big bang when it lands … |
jowady | 17 Feb 2017 4:10 p.m. PST |
Probably the biggest caliber ranging guns were the XI inch Rodman on the US Navy's ACW Monitors. The XI gun was used for ranging and targeting the XV inch gun. |
ghostdog | 18 Feb 2017 2:23 p.m. PST |
Okey, i had heard about using the 50. Hmg as a ranging weapon, but i am curious about the coincidence range finders in tanks, bfore the laser rangefinder. Were they acurate enough? I am a bit surprised by combat capitan post, that you can estimate the range with a 10% error, and this isnt still enough to warranty an impact. |
troopwo | 18 Feb 2017 5:01 p.m. PST |
The US was big on the co-incedence range finders. Think of it as a two piece optical set up. One range finder optic on either side of the turret. You look at the target and it presents a top and a lower image. The gunner dials the two images together until they blend and then reads off the range. This was referred to as, "flying the geese", since the top and bottom images had a series of v shapes that matched up. He then applies it to the scale on his gun sight. It was used mostly to get accurate ranges for HEAT rounds. The tanks known for it were the M47, |M48 and I am not sure about the M60. I am pretty sure the early A1 and A2 Leopard Ones used this. It does take a short few seconds to focus. I prefer the ranging gun myself, but it was really a matter of tank crew training and knowing how to use and get the most out of your equipment. |
goragrad | 18 Feb 2017 7:49 p.m. PST |
From Centurion AFV Profile the ranging machine gun was stated to have given the Indians the advantage over the Pakistani Pattons with stereoscopic rangefinders in at least one of the major battles. |
troopwo | 19 Feb 2017 3:12 p.m. PST |
There was always the argument of which was bettter and faster. I suspect that the Indians were a littke better trained and proficient in the '65 war for sure. I still have the Centuion gunnery precis in my basement somewhere. (Precis, service publication for all the details on the gunnery from theory to where each nut and bolt is and their thread type.) |
Thomas Nissvik | 22 Feb 2017 7:15 a.m. PST |
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Legion 4 | 22 Feb 2017 8:17 a.m. PST |
Yes, it is like you are taking a "Practice Shoot" to see if you can hit the target. Then bring out the "Big Guns" to do the job. But today with all the high tech ranging equipment. It seems that is generally not seen very often AFAIK. |