Warhead data

[nuke11]

Originally Posted by ArmySGT.

Hi Nuke!

Is this still current? I am thinking of going on a non-U.S. ATGM game stats spree....... Would this list be the most current still?

I need to add Caribbean, Central America, Canadian, and more Soviet to the threats to Project or KFS equipment.

May even do some torpedoes and anti-ship weapons.

Yes this is still my current work. I've been digging around for Soviet information, but it seems to be a bit harder to find for some reason.

[ArmySGT.]

For M102 Howitzer (KFS issue) towed behind one M35 2 1/2 ton truck.

Caliber: 105mm
Weight: 1500kg
ROF: 5 round per minute
Maximum range: 14,000 Meters
Feed Device: Single shot, screw type breech
Basic Load: 150 rounds
Ammunition types: HE, WP, Illum
Crew: 8



Name M1 105mm HE
E-Factor =
DPW = 6136 (2.63084kg Compostion B) or 3771 (2.17724kg TNT)
Wt. 39.92 lbs (18.107407 kg)
Eff. Range 11500m
Max. Range 11,500m
Burst Radius 25m
Type of Fire single shot, screw type breech
Rate of Fire Single
Feed Device n/a
Feed Device Wt. Manually loaded
Basic Load 150 rounds
Load Wt.
Total Wt.
Additional Comments:Very basic HE artillery shell. Maybe fitted with a variety of fuses for air burst (Variable Time (VT)) which is preferred, impact, delay, and contact fuses.
Limitations:
Functional reliability will be degraded when impacting soft targets such as marshy, sandy, clay, mud, or snow covered terrain.

Use:
The projectile of this cartridge contains high explosive and is used for fragmentation, blast, and mining in support of ground troops and armored columns.

Description:
The projectile consists of a hollow steel forging with a boattail base, a streamlined ogive, and gilding metal rotating band. A base cover is welded to the base of the projectile for
added protection against the entrance of hot gases from the propelling charge during firing. The high explosive (HE) filler within the projectile may be either cast TNT or Composition B. A fuze cavity is either drilled or formed in the filler at the nose end of the projectile. This cavity may be either shallow or deep. A cavity liner, to preclude dusting of HE during transportation and handling, is seated in the cavity and expanded into the lower projectile fuze threads. A supplementary charge is placed in the fuze cavity of projectiles having deep cavities. Projectiles with shallow cavities or deep cavities containing a supplementary charge use only short intrusion fuzes, PD, or MT. Those with deep cavities will accept the long intrusion proximity fuze after removing the supplementary charge. Projectiles may be shipped with a PD or MTSQ fuze or with a closing plug. When
shipped with a closing plug, a chip board spacer is assembled between the supplementary charge and plug to limit movement of the former during transportation and handling.
The cartridge case contains a percussion primer assembly and seven individually bagged and numbered propelling charge increments. The base of the cartridge case is drilled and the primer assembly is pressed into the base. The percussion primer assembly consists of a percussion ignition element and a perforated flash tube containing black powder. The seven numbered increment bags are tied together, in numerical order, with acrylic cord. These are assembled into the cartridge case, around the primer flash tube, with Increment 1 at the base of the cartridge case and Increment 7 toward the mouth of the cartridge case.

Functioning:
If the projectile is unfuzed, the closing plug is removed and a fuze assembled to the projectile prior to adjusting the charge and loading the cartridge into the weapon. Impact of the weapon firing pin results in the initiation of the percussion primer which, in turn, ignites the black powder in the flash tube. The flash tube provides for uniform ignition of the propelling charge producing a rapid expansion of the propellant gas which propels the projectile out of the weapon tube. Engagement of the projectile rotating band with the rifling of the weapon tube imparts spin to the projectile providing inflight stability. Projectile functioning is dependent upon the fuze used and may function on impact (instantaneous or delay), function above ground either at a predetermined height based upon time of flight or function in proximity with the target area. Fuze function detonates the HE projectile filler resulting in projectile fragmentation and blast.

[ArmySGT.]

CARTRIDGE, 25MM, ARMOR PIERCING DISCARDING SABOT-TRACER, M791
For use in M242 Bushmaster cannon.


M791 APDS-T.pdf

[ArmySGT.]

Cartridge, 25mm, armor piercing fin stabilized
discarding sabot-tracer, m919

M919 APFSDS-T.pdf

[ArmySGT.]

CARTRIDGE, 25MM, HIGH EXPLOSIVE INCENDIARY-TRACER, M792
For use in M242 Bushmaster cannon.

M792 HEI-T.pdf

[ArmySGT.]

https://en.wikipedia.org/wiki/Relati...iveness_factor

Should a new formula include the detonation velocity to figure DPW?

[mmartin798]

Originally Posted by ArmySGT.

https://en.wikipedia.org/wiki/Relati...iveness_factor

Should a new formula include the detonation velocity to figure DPW?

This may be a place to start:

[ArmySGT.]

Originally Posted by nuke11

Yes this is still my current work. I've been digging around for Soviet information, but it seems to be a bit harder to find for some reason.

Did I send you the Defense Intelligence Agency munitions guide I have?

I got it off of Scribd.... Which has been a good source for these.

[nuke11]

Ok, the problem you have at the moment is the document is based on TNT equivalent of an RE of 1.00. The game uses C4 as it's equivalent for an RE of 1.00 and TNT has an RE of 0.75 in the game.

You will need to adjust all of the formulas from the document accordingly.

Doesn't the M67 have a solid steel case that also needs to be taken into account for the fragments? Here is a good website that shows what some of the fragments look like: http://machinesforwar.blogspot.ca/2012/03/m67.html

Some more images of the inside of the case and what the fragments look like: http://www.big-ordnance.com/grenades...CutawayM67.jpg and http://www.big-ordnance.com/grenades/loworderM67.JPG

The M26 is the grenade with a spiral wound wire core: http://img.photobucket.com/albums/v1...ut/OR-034A.jpg

[mmartin798]

Originally Posted by nuke11

Ok, the problem you have at the moment is the document is based on TNT equivalent of an RE of 1.00. The game uses C4 as it's equivalent for an RE of 1.00 and TNT has an RE of 0.75 in the game.

You will need to adjust all of the formulas from the document accordingly.

The Gurney equations don't care about the RE at all. It only uses the uses the Gurney constant which does not necessarily correlate with RE. Taking the example of making C4 1.00 and TNT 0.75, we would expect TNT to perform at 75% of C4. But that is not the case. C4 has a Gurney constant of 2530 m/s and TNT is 2438 m/s, which makes TNT perform at 96% of C4. The equation in my spreadsheet uses the approximation of the Gurney constant, which is one third of the detonation velocity. For C4 that works out to 8200/3 or 2733 and TNT is 6900/3 or 2300. That makes TNT 84% of C4, which is closer to the 75% you are looking for already.

Originally Posted by nuke11

Doesn't the M67 have a solid steel case that also needs to be taken into account for the fragments? Here is a good website that shows what some of the fragments look like: http://machinesforwar.blogspot.ca/2012/03/m67.html

Some more images of the inside of the case and what the fragments look like: http://www.big-ordnance.com/grenades...CutawayM67.jpg and http://www.big-ordnance.com/grenades/loworderM67.JPG

The M26 is the grenade with a spiral wound wire core: http://img.photobucket.com/albums/v1...ut/OR-034A.jpg

The method of determining fragment size was an approximation intended to simplify the math and make fragments of uniform dimensions that can be directly plugged into the EFactor equation. While we could take the mass of the case and the diameter of the grenade to determine an approximate thickness and then divide the surface area up into the number of fragments to get the area of the face which is more accurate as to what happens with the case of the M67, we are then stuck with fragments that are essentially flat tiles. There is no diameter that we can reasonably put through the EFactor equation as it is shown in the rules. Even though we can calculate the kinetic energy of these flat tile fragments, that is still not enough information to determine the wound generating capability of the fragments. KE alone has been shown time and time again to bot be reliable in wound cavity calculation. The EFactor used in the rules is similar to wound approximation models for significant number to ballistic rounds. So while the wire core is not what happens with an actual M67, it works better for incorporating with the EFactor of other weapons in the game.

[nuke11]

Ok, what happens if a square wire coil is used instead? From the M26A2 the wire is about 3 mm square and lets assume the coil is fragmented every 3 mm for a 3 x 3 cube how does this impact the results?

http://i.imgur.com/FvWF19q.jpg

[ArmySGT.]

[mmartin798]

A few things change. The fragments are slightly heavier with a mass of 0.21g, versus 0.1g. The M26A2 has 0.16 kg of filler, which is a little less. However, that makes no difference to the initial fragment velocity, which is still 3276 m/s. The larger fragments have a higher EFactor initially of 25.

[mmartin798]

I have been thinking about the way grenade damage is applied in game versus the calculations I have been working with and the killing and casualty causing radius of the M67.

The rules give the M67 a 15m burst radius. The M67 has a killing radius of 5m and a casualty causing radius of 15m. So far they seem in agreement.

3rd edition has 1d20 fragments of Efactor 4 for any one in the burst radius. So wearing resistweave coveralls will keep you safe from fragment damage and you only take the full body damage from the DPW of the filler.

4th edition has number of fragments hitting equal to DoS*(Burst radius - actual radius). So we have Kevin, a Marine recon sniper with STR 26 and no specialization in thrown weapons chuck an M67 at Floyd 30m away, rolls a 37 which hits with a DoS of 3. The grenade explodes 9m from Floyd creating 3*(15-9) or 18 fragments with 1+ DoS * 2 or 7 fragments hitting of Efactor 4 each. Again the resistweave coveralls are great.

Using the real world data, assuming uniform fragment distribution, 1335 fragments disbursed and an human silhouette are of about 0.8m^2, we have 4.2 fragments hitting that silhouette at 5m with an Efactor of 17. At 10m we have 1 fragment with an Efactor of 14. At 15m, we have 0.5 fragments with an Efactor of 11. So here at 5m, resistweave bring us 3-5 fragments doing 10 dp each, at 10m, that is 1-2 doing 7 dp each and at 15m we have 0-1 fragments doing 4dp.

Clearly the rules don't really represent the real world data well. But are we satisfied with the rules or could they stand a tweak?