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Version 1.5
January 9, 2000
For every 5 points of STR under the Recoil Strength Min required to fire a weapon, there is a -2 OCV modifier in the firing character's next phase (and this phase if conducting an auto fire or double fire attack), and a 1d6 normal attack this phase. Also, if the STR Min is over 30, add an additional 1d6, increasing by 1d6 for every 5 points of STR Min over 30. Only a character's PD characteristic may be used to defend against this damage.
The OCV penalty suffered in the following phase may be avoided by taking a 1/2 phase maneuver to regain control of the weapon.
The recoil energy of a firearm is found by:
recoil energy, joules = (mp * vp / 1000)2 / (2 * mw)
mp = mass of projectile, grams
vp = velocity of projectile in m/second
mw = mass of weapon in kilograms
The basic Recoil Strength Minimum is calculated from the recoil energy as follows:
Recoil STR Min = 5 * log2(recoil energy, joules)
The actual Recoil Strength Minimum will depend upon the construction and operation of the weapon, and the method of employment. Apply the following modifiers to the basic value derived above:
| action | mod | type of action | notes |
|---|---|---|---|
| -1 | non-automatic | bolt action rifles, revolvers, muskets, etc. | |
| -3 | automatic | most semi and full automatic firearms | |
| -5 | recoil delay | exotic recoil absorbing systems | |
| muzzle brake | mod | features | notes |
| -1 | simple muzzle brake | found on some pistols, SMGs or assault rifles | |
| -3 | complex muzzle brake | found on some very heavy rifles or machine guns | |
| -2 | gyro stabilization | nbsp; | |
| -1 | customized | stock fitting, custom grips, etc. | |
| rate of fire | mod | rounds/phase | notes |
| +5 | 3 to 5 | 300 RPM minimum | |
| +10 | 10 | 600 RPM minimum | |
| +15 | 20 | 1200 RPM minimum | |
| +20 | 40 | 2400 RPM minimum | |
| etc. | etc. | etc. | |
| employment | mod | how employed | notes |
| -5 | two handed | ||
| -5 | attacker Braced | ||
| -5 | stock on shoulder, while Braced |
Most ranged weapons also have a Suspension Strength Minimum; this is determined as:
Suspension STR Minimum = (log2(massweapon,loaded) * 5) + employment mod
| mod | employment |
|---|---|
| +5 | one handed |
| 0 | two handed |
| -5 | attacker Braced |
| -5 | stock on shoulder, while Braced |
The effects of insufficient strength when firing a weapon exceeding the Suspension Strength Minimum are the same as for Recoil Strength Minimum, except no damage is done. Both strength minimums should be calculated for each weapon, but only the larger should be noted -- if they are identical, use the Recoil Minimum. Our firing tables mark weapons having a larger Recoil Minimum with an asterisk, those with a larger Suspension Minimum are left unmarked. Obviously, in low-gravity or zero gravity environments, Suspension Strength Minimum should be reduced or ignored.
Example: the Charter Arms Bulldog Pug revolver has a mass of 0.54 kg, and it fires a 13 gram bullet at 300 meters per second (in .44 Special caliber). The recoil energy is 14.1 joules, and the basic Recoil STR Min is 19. Its action reduces this to a 'mere' 18 Recoil STR Min if fired one-handed, or a 14 Recoil STR Min if fired two handed. Madame Hong, with a STR of 10, will take a 0.5d6 normal attack each time she fires it two-handed, and will suffer a -2 OCV penalty her next phase. The Suspension STR Minimum is 0 one-handed, or -5 two handed, and would thus not be noted on the firing tables.
Example: the McMillan M-87 bolt action .50 cal rifle has a mass of 10 kilograms, and it fires a 40.5 gram bullet at 930 meters per second. The recoil energy is 71 joules, and the base Recoil STR Min is 30. The weapon's non-automatic action and complex muzzle brake reduce the STR Min to 27; when fire two handed from a Braced (prone) position, with the stock against the attacker's shoulder, the Recoil STR Min is 12. Madame Hong will suffer a 0.5d6 normal attack, and will be -2 OCV on her next phase. The Suspension STR Min is 7 when fired as described, and would not be noted on the firing table.
Example: Biker Bob (STR 18) hip-fires a full-auto (5 round) burst from a modified Panther Assault Cannon. The 24.5 kg weapon requires a Recoil STR of 26 to fire on single shot, 2 handed and Braced; since Bob is not Bracing, and is firing a 5 round burst, the actual Recoil STR Min for this shot is 36. Due to the 18 point STR shortfall he will take 2d6 + 2d6 = 4d6 of normal damage; he will be -8 OCV this and the next phase. Again, Suspension STR Min is "only" 23 when used two handed, and not noted in the firing tables.
In order to generate Range Mods for small arms, an effective range must be known for the weapon being considered. Unfortunately, there are no standardized, official, used-in-all-countries methods of computing effective range. Different sources can differ by 30-50% on the value for effective range of a given weapon. Different methods are used to determine effective range for different classes of weapons. Thus, four procedures are presented to generate Range Mods for small arms. Select the procedure which seems appropriate for the weapon being simulated.
For each procedure, the 'total OCV' is the sum of the weapon OCV modifiers and sight OCV modifiers for Set and Brace. Round resulting fractions up or down at the referee's discretion.
Pistols, and stockless weapons fired at moving human sized targets:
( effective range, meters )
RMod, hexes = ------------------------------ - sight RMods for Set and Brace
4 * (2 + OCVtotal)
Example: a Smith and Wesson M&P .38 Special (+1 OCV) is fitted with fixed sights (+1 OCV for Set or Brace). The effective range is given as 50 meters. Therefore, the total Range Mod for this weapon is 50/(4 * (2 + 1 + 2)) = 2.5 hexes. We will round this to -1 per 2 hexes (though an argument could be made for -1 per 3 hexes).
Submachineguns, and stocked weapons fired single shot at stationary head and torso sized targets:
( effective range, meters )
RMod, hexes = ------------------------------ - sight RMods for Set and Brace
8 * (2 + OCVtotal)
Example: the Uzi (+2 OCV single shot) is normally fitted with a battle sights (+1 OCV for Set or Brace, +1" Range Mod for Set and Brace). Its effective range is given as 200 meters; thus the Range Mod is 200/(8 * (2 + 2 + 2)) - 1 = 3.17 hexes ~ -1 per 3 hexes.
Rifles, and stocked weapons fired single shot at stationary man-sized targets:
( effective range, meters )
RMod, hexes = ------------------------------ - sight RMods for Set and Brace
8 * (5 + OCVtotal)
Example: an M14 rifle (+1 OCV) fitted with a standard sight (+1 OCV and +1" Range Mod for Set or Brace) has a maximum effective range of 700 meters. The total Range Mod is 700/(8 * (5 + 1 + 2)) - 2 = -1 per 8.94 ~ -1 per 8". Note that the 700 meter effective range is considered optimistic . . . some sources give values as low as 550 meters; thus the large 'round down.'
Example: an M21 sniper rifle (+1 OCV) fitted with an ART telescopic scope (+2 OCV and +2" Range Mod for Set or Brace) has a maximum effective range of 1000 meters. The total Range Mod is 1000/(8 * (5 + 1 + 4)) - 4 = -1 per 8.5" ~ -1 per 9".
Machine-guns: as procedure #3, but taking Bipod (or Tripod/Mounted) and Auto Fire OCV bonuses into account.
Example: the M60 machinegun (+1 OCV) is fitted with standard sights (+1 OCV and +1" Range Mod for Set or Brace) and a Bipod (only subtract 1/4 Range Mod penalty for autofire). It fires at a cyclic rate of 550 RPM, close enough to 600 RPM for 10 round bursts (+4 OCV), and is given an effective range of 800 meters. The initial Range Mod will be 800/(8 * (5 + 1 + 4 + 2)) = 8.33". To figure the actual Range Mod, multiply 8.33" by 4/3 (the inverse of the Bipod Range Mod effect), giving 11.1"; finally 11.1 - 2 = 9.1", rounds to -1 per 9".
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Document last modified Friday, June 01, 2001