Speed of M10 GMC (US Army)
 

OOB12(US Army) Unit 016 & 020 (M10 GMC) are of speed 14.
I checked with some resources, like:
http://afvdb.50megs.com/usa/3ingmcm10.html
&
http://www.wwiivehicles.com/usa/tank-destroyers/m10.asp
It seems M10 GMC should have a faster speed.

And its 3inch gun has the same stats as those of the 76mm gun used by later sherman. Should the 76mm gun be more powerful (or the 3in less powerful)?

BTW
Which speed is used in OOB, the max one or the sustained one?

Best Regards
Ironfist

Re: Speed of M10 GMC (US Army)
 

The speed does appear to be a little low. There is a thread running in the WinSPMBT forum that said a unit's speed should be their speed in kph divided by 3. Since most sources put the speed around 50kph, that works out to in the range of 17.

As for the gun, both fired the same round based on what I found. If the barrel lengths are close and consequently the muzzle velocity, the penetration values should be pretty much the same.

Re: Speed of M10 GMC (US Army)
 

For ballistic performance, both 3in and 76mm guns are the same, as they were designed to be so - 76mm is just 3-incher with new breech and shorter (but wider) ammo cases so that it is possible to operate it in Sherman turret.

Re: Speed of M10 GMC (US Army)
 

The reference I saw gave the impression the rounds were interchangeable, but did also mention the cases were different. A shorter breech on the Sherman gun makes the case was shorter and wider, but it sounds like both had the same amount of propellant. In that case, the rounds wouldn't be interchangeable. Still, they would have had the same penetration. As I understand it, both guns were based on the 3in flak gun. Seems to be a common relationship between flak and tank guns during WWII.

Re: Speed of M10 GMC (US Army)
 

The PROJECTILES were the same, ie both guns used M62 APC Projectile and M93 HVAP Shot, but they were stuck to different cases, which had the same final amount of propellant, jsut different shape.
Same thing as with Brits, 17 pdr and 77mm OQF had the same caliber and used the same projectiles, just in different cases, this time with different amounts of propellants and different barrel lengths IIRC.

Re: Speed of M10 GMC (US Army)
 

There are a variety of speeds quoted for that vehicle but it does appear it should be 16 or 17 not 14.

Don

Re: Speed of M10 GMC (US Army)
 

In addition to spob012 USA units 016 & 020, there are some other WinSPWW2 OOBs using the M10/Wolverine/Achilles that will need to be taken care of, as well:

spob02 Poland - units 132, 133
spob06 France - units 083, 084
spob07 Great Britain - units 044, 155, 187, 223
spob11 Soviet Union - unit 475
spob27 Belgium - units 255, 256, 257
spob31 Canada - units 030, 043, 044, 155

Hopefully, I found all of them. The handful of M10s I could find in WinSPMBT such as obat04 Israel – unit 478 were already at a speed of 16.

Ross

Re: Speed of M10 GMC (US Army)
 

already done.......:)

Don