rexford Posted October 8, 2003 Share Posted October 8, 2003 The following tidbits suggest that smoke was not available for the Sherman 75mm gun during the African campaign, and coaxial machine guns were used to an unknown degree for range estimation: Sherman Field Manual FM 17-12 indicates for "SMOKE SHELL" that "Smoke shell for tank guns is under development. The smoke shell now issued for the 81-mm mortar is very effective for screening. (See FM 17-27.)" The date of the FM 17-12 is April 22, 1943. The gun sight for Sherman 75mm in FM 17-12 includes range markings for SHELL SMOKE (WP) MK II, with a maximum range of 2200 yards. FM 17-12 has a section on "DETERMINATION OF RANGE, a. Estimation by Eye" which suggests use of the coaxial machine gun for range estimation by Shermans. "By firing a coaxial machine gun - Fire the machine gun with an estimated range and roll the strike into the target. The point on the reticle at which the strike appears is the range setting for the machine gun. Refer to the sight diagram and determine the corresponding range setting for the tank gun." 0 Quote Link to comment Share on other sites More sharing options...
K_Tiger Posted October 8, 2003 Share Posted October 8, 2003 This MG range finding sounds odd! Is it described when a range estimation brings better result then the standard gun optics? I`ll estimate, even a sherman will not have to many problems to find the range till 800 meters...and to hit a target over this distance with an MG without optics...its possible..but doubtfuly. If this works i wouldn use it. I would prefer to try to zero in with the main gun...even i miss with some shoots...but plinking with MG bullets on an ennemy tank is like knocking on a door and saying "here i am, shoot me".. 0 Quote Link to comment Share on other sites More sharing options...
Mr. Tittles Posted October 8, 2003 Share Posted October 8, 2003 I downloaded TM 9-1904. I dont know what year its from but it references AP, HE and WP shells for the 75mm gun. WP is M64. HE is two types, M48 and M41A1. 0 Quote Link to comment Share on other sites More sharing options...
Redwolf Posted October 8, 2003 Share Posted October 8, 2003 Originally posted by K_Tiger: This MG range finding sounds odd! Is it described when a range estimation brings better result then the standard gun optics? I`ll estimate, even a sherman will not have to many problems to find the range till 800 meters...and to hit a target over this distance with an MG without optics...its possible..but doubtfuly. If this works i wouldn use it. I would prefer to try to zero in with the main gun...even i miss with some shoots...but plinking with MG bullets on an ennemy tank is like knocking on a door and saying "here i am, shoot me".. Well, the MG is used by varying elevation, too, it is not expected to hit instantly either. The MG can do that in a fraction of the time and it doesn't waste main gun ammo. 0 Quote Link to comment Share on other sites More sharing options...
Abbott Posted October 8, 2003 Share Posted October 8, 2003 Originally posted by K_Tiger: This MG range finding sounds odd! Is it described when a range estimation brings better result then the standard gun optics? I`ll estimate, even a sherman will not have to many problems to find the range till 800 meters...and to hit a target over this distance with an MG without optics...its possible..but doubtfuly. If this works i wouldn use it. I would prefer to try to zero in with the main gun...even i miss with some shoots...but plinking with MG bullets on an ennemy tank is like knocking on a door and saying "here i am, shoot me".. Using the coax works by observing the impact of rounds fired. Walking the fall into the target. It is used to quickly gauge range to target and can be effective in some circumstances. Remember as late as Vietnam a .50cal was used to determine range on some recoilless guns. 0 Quote Link to comment Share on other sites More sharing options...
K_Tiger Posted October 8, 2003 Share Posted October 8, 2003 I belive you..thats not the problem..but doesnt both weapons have different charakteristics in her ballistics..? (Wireds english i ever wrote.. ). So you have at least to zeroed in your coax MG with your main gun before the battle..was this overall common? 0 Quote Link to comment Share on other sites More sharing options...
Redwolf Posted October 8, 2003 Share Posted October 8, 2003 The plan is not to use the same elevation. You use the MG to get the range, as in a number of meters and then you adjust the main gun with that knowledge. From past threads I also remember they are actually more similar than one would assume. 0 Quote Link to comment Share on other sites More sharing options...
Abbott Posted October 8, 2003 Share Posted October 8, 2003 Originally posted by K_Tiger: I belive you..thats not the problem..but doesnt both weapons have different charakteristics in her ballistics..? (Wireds english i ever wrote.. ). So you have at least to zeroed in your coax MG with your main gun before the battle..was this overall common? You are correct. The ballistics of the weapons differed greatly. I have no idea how often the coax was zeroed with the main gun in the time period being discussed. I am sure one of our resident Grogs will post the needed information. 0 Quote Link to comment Share on other sites More sharing options...
JonS Posted October 9, 2003 Share Posted October 9, 2003 Originally posted by K_Tiger: Is it described when a range estimation brings better result then the standard gun optics?The Sherman optics didn't have a way to estimate range - it had to be done by eyecrometer or some other method. Regarding the CoAxMG and the main armament having different ballistics: so what? They are both known, and from the peices of known information (ballistics of A, ballistics of B, elevation and therefore range using , the unknown (elevation to acheive range with A) is fairly trivial to determine. More to a point, a simple conversion chart based on the above in (for example) 200-yard steps, that the gunner could memorise, would seem more likely than expecting the gunner do some quick calculus on the fly while engaged in combat. Regards JonS 0 Quote Link to comment Share on other sites More sharing options...
gibsonm Posted October 9, 2003 Share Posted October 9, 2003 Originally posted by K_Tiger: So you have at least to zeroed in your coax MG with your main gun before the battle..was this overall common? Well I currently boresight both main and coax. So I don't see why they didn't during the Second World War. Perhaps they didn't have time to put up zeroing screens, measure zero displacement etc. but I'm sure they would have "Battle Zeroed" and made adjustments whenever possible. Bit untidy to be on the "two way rifle range" and have your sights not correspond with the round's trajectory! [ October 08, 2003, 06:49 PM: Message edited by: gibsonm ] 0 Quote Link to comment Share on other sites More sharing options...
K_Tiger Posted October 9, 2003 Share Posted October 9, 2003 Did i offend you in any way? The Sherman optics didn't have a way to estimate range - it had to be done by eyecrometer or some other method I know this, but even tiger crews didnt hit allways with the first shot on longer distances. I was too thinking, that every miss you can call a range estimation. 50 in front, 50 meters behind..boom..on Target. I was thinking that this doesnt differs, if you use optics with or without range estimations. The first will give you better results but the system should be the same, at the end. Please correct me, if im wrong, im open minded and want to know the truth. Regarding the CoAxMG and the main armament having different ballistics: so what? They are both known, and from the peices of known information (ballistics of A, ballistics of B, elevation and therefore range using , the unknown (elevation to acheive range with A) is fairly trivial to determine My mistake, i meant more the flight charakteristics of those light weight .30 bullets compared to a gun round. Wasnt the coax mg intended for close defense? I know what you mean and how it was done..but still hard to understand. When you shoot 20 bullets over a long distance maybe 10 will hit the other 10s miss...how you know that you are on target? As i remember correctly..you can lead it to the target but the pattern over greather distances are wide. The main question should be: which range was the best for this sort of aiming? And how big was the benefit compared to the regular aiming...please in seconds.. 0 Quote Link to comment Share on other sites More sharing options...
rexford Posted October 9, 2003 Author Share Posted October 9, 2003 The sight diagram for M3 75mm gun with telescopes M32, M38 or M55 has this relationship between CAL .30 AP MG bullets and SHOT A.P. M61 for the same elevation angle: M61 APCBC 600 yards, coax MG 700 yards M61 APCBC 1000 yards, coax MG 1000 yards M61 APCBC 1500 yards, coax MG 1200 yards M61 APCBC 2000 yards, coax MG 1400 yards M61 APCBC 2500 yards, coax MG 1600 yards M61 APCBC 3000 yards, coax MG 1800 yards Gun elevation angle increases as one heads down the sight. Setting the 75mm gun for an M61 APCBC shot to 2000 yards uses the same elevation angle as the coax MG firing at a 1400 yard target. With coax MG range estimation, roll the MG bullets until they fall onto the target and note the range on the MG sight markings. Say it is 1200 yards. Since one estimates the target range to be 1200 yards based on the coax MG, a shot with M61 APCBC would then use an elevation for that ammo which results in a 1200 yard shot. And the 75mm M61 APCBC shot against a target range of 1200 yards would result in a gun elevation angle less than the coax MG at the same range. [ October 08, 2003, 08:30 PM: Message edited by: rexford ] 0 Quote Link to comment Share on other sites More sharing options...
JonS Posted October 9, 2003 Share Posted October 9, 2003 Originally posted by K_Tiger: Did i offend you in any way? Nope. :confused: </font><blockquote>quote:</font><hr /> The Sherman optics didn't have a way to estimate range - it had to be done by eyecrometer or some other method I know this, but even tiger crews didnt hit allways with the first shot on longer distances. I was too thinking, that every miss you can call a range estimation. 50 in front, 50 meters behind..boom..on Target. I was thinking that this doesnt differs, if you use optics with or without range estimations. The first will give you better results but the system should be the same, at the end. Please correct me, if im wrong, im open minded and want to know the truth.</font> 0 Quote Link to comment Share on other sites More sharing options...
K_Tiger Posted October 9, 2003 Share Posted October 9, 2003 This range estimation with mg bullets ive got allready...no wonder with the help from the biggest grogs around..thats why i love this forum.. @Lorrin "roll the MG bullets until they fall onto the target"....and made top hits... 1200 meter sounds fare vor mg rounds even if you use it only for range estimations. We have discussions about death-clock before CMBB...thats because in real gunners dont know every time that they hit/penetrated his target. If they have to determine mg hits over such a distance, this should be real difficult to spot such smal caliber hits and only under verry good conditions (clear sight, no wind). I summarize... you need numerical odds, alot of time, good conditions..ect. and should avoid head on firefights (over 1200 yards) with guns 75mm and upwards. @JohnS I don't know what you mean here, but I will guess that you are asking which method was best for first round accuracy? Yes and no, it was more from interrest for me, when the sherman gunners used this method over the standard one and under which circumstances and ranges. I dont think that it was standard, we would have read more about it. For sure you have a better insight in the US doctrins than i. But thanks again, helpfully like always. 0 Quote Link to comment Share on other sites More sharing options...
Guest Mike Posted October 9, 2003 Share Posted October 9, 2003 1200m is wel withing full-calibre fifle-ammo range (ie .30, .303, 7.92, 7.62,mm, etc) - I suspect the actual limit for range estimation using this method is the life of tracer in the round, since bullet impacts are not likely to be seen at such a range even with magnification! I don't remember what the burnout range for tracer was when I as a SFGPMG crewmwmber - 1400m?? And that was for post war 7.62mm NATO. 0 Quote Link to comment Share on other sites More sharing options...
K_Tiger Posted October 9, 2003 Share Posted October 9, 2003 1200m is wel withing full-calibre fifle-ammo range (ie .30, .303, 7.92, 7.62,mm, etc) - I suspect the actual limit for range estimation using this method is the life of tracer in the round, since bullet impacts are not likely to be seen at such a range even with magnification What means well? A usefull range where you still able to controll it or the range the Bullets start to fall down due to gravitation? Even with tracers...on a bright day, it will not made a big different. I saw on a maneover a 5cm autogun shooting...those tracers i have seen...but this is another story..compared to rifle bullets. Oh...this lead me to another question...whats with afternoon or early morning, or overall dark weather...those muzzle flashes should be, like cigarrets and soldiers, give a nice target. 0 Quote Link to comment Share on other sites More sharing options...
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