Re: FF&S firearm designs
In reply to #6347 FF&S firearm designs by Mark Urbin
[email removed] (Mark Urbin) wrote: > I've been reading the archives of the Beta test group. I noticed someone > was designing a *large* rifle. In the 15mm range. From what I remember, > *large* weapons were coming out much bigger than their real-life counter- > parts. Is that still true or did GDW come up with a fix? I don't know what the final rules look like, but GDW was looking at that part of the design and considering changes. One change that they almost certainly made was to base receiver length on the "average" energy (and not actual energy), which for these long, heavy guns would reduce the mass of the receiver somewhat. One fix that was suggested was to use a different basis for computing the receiver mass; I don't know if this change was made official or not. > If the 15mm rifle came out fairly close to what the designer was looking > for, I'd like to hear about it. I just finished re-reading Pournelle's > Falkenberg's Legion books and noticed the 15mm sniper rifle used by the > Royal Spartan Army and their Helot foes. The 15mm rounds ignored the > `improved Kevlar' used and was effective against light armored vehicles. > Does the FF&S designs live up to this? See below. I "designed" a WWII-era Soviet weapon that will punch pretty effective holes in most personal armor. I'm certain that any changes to FF&S since the draft I was using wouldn't change the damage or penetration of the weapon, so you can use the "real world" values for the weapon (included below) and the FF&S-generated game statistics to put this weapon in your games now. Peter H. Brenton [email removed] wrote: > for those of us not particularly familiar with real-life weapon > diameters (or at least not in millimeters) could you put this into > context please? > I *thought* that a 30-06 rifle had a round 6/10ths of an inch in > diameter (this doesn't sound right to me). Sure. The short answer is that the caliber of the weapon is the diameter of the projectile, in inches or millimeters. Therefore, a .30-06 is 0.30 inches in diamater (that's 3/10ths). The 15mm rifle would be fire a 0.591 inch projectile (25.4mm = 1inch). That's nearly twice the diameter of the .30-06. > This can't be right if your talking about 15mm > being a *large* rifle, I assume your talking about an elephant rifle, > not a deer rifle. Could someone please correct me? Actually, we're talking about a military weapon, and it bears little resemblance to either a deer rifle or an elephant rifle. Historically, this class of rifle was designed in the late 30's and early 40's in an attempt to design an infantry weapon that could penetrate the armor of a tank. Tank armor rapidly outstripped the ability of small-arms to penetrate, and in general the weapons were used agains unarmored or lightly armored vehicles, or agains infantry under cover, and the weapons fell out of use. Relatively recently, similar designs have been used as long-range sniper rifles. The large bullet, fired at high velocity from a long barrel, as a very flat trajectory and is less affected by wind, making accurate long range fire possible. On the GDW-Beta discussion group, I took one of the WWII era weapons, and someone else did a modern one. In many cases, the cartirdge these weapons fire was used in large machineguns as well, and has the same general characteristics; although the muzzle velocity is a little higher due to the longer barrel of the sniper or anti-tank weapon. Note that *both* of these calibers are larger than the US .50 caliber (12.7mm) M2HB machinegun. > It would also be helpful to me if someone could post a list of standard 'real' > weapon calibers and show their diameter in mm (ie. .357 Magnum=XXmm pistol). Sure. Here's a table that gives dimensions in mm, and the "common name" of just about every round that was readily available for research. You can figure out the diameter in inches by dividing the size in mm by 25.4 (this is an exact conversion). I also listed some of the more common weapons that use this ammunition, in the hopes that either the common name or a weapon name would provide a memory handle you can use to relate everything. Pistol and rifle rounds are listed together on the list; you will notice that pistols generally have shorter cartridges, though. Designation Name Used In (typical weapons) 4.7x21mmC 4.7mm Caseless Heckler & Koch G-11 5.45x39mm (unknown) AKS-74 5.56x45mm .223 Remington M16A1, FN-CAL, Valmet M82, Galil ARM 5.7x17mmR .22 Long Rifle High Standard .22, AR-7 6.35x15.5mmSR .25 ACP or .25 Auto Colt .25 Automatic 7.62x25mm .30 Mauser Mauser M1896, Tokarev M1933, PPsh-41 7.62x39mm 7.62 Short SKS, AK-47, AKM-47, RPD, RPK 7.62x51mmR .30-30 Winchester 94 7.62x51mm 7.62 NATO or .308 Win M-14, FN-FAL, L42A1, G-3, M60, Minigun 7.62x54mmR 7.62mm Russian SVD, SG-43, PKM, Vz-59 7.62x63mm .30-06 Springfield M1903, M1 Garand, BAR 7.62x66mmB .300 Winchester Magnum Walther WA-2000 7.65x17mmSR .32 ACP or .32 Auto Welrod "Silent", Vz-61 "Skorpion" 7.7x56mmR .303 British Enfield, Vickers, Lewis, Bren 7.7x58mm 7.7mm Arisaka Arisaka M99 (WWII Japanese rifle) 7.92x57mm 8mm Mauser Kar-98k, FG-42, MG-08, MG-34, MG-42 8x21mm 8mm Nambu Type 14 Nambu (WWII Japanese sidearm) 9x17mm .380 Auto or 9mm Short Walther PPK, Ingram M11 9x18mm 9mm Makarov P64, Makarov, Stechkin, PM-63 9x19mm 9mm Parabellum (9mmP) Luger P-08, S&W M39, UZI 9x29mmR .38 Special or .38 S&W Colt Police Positive 9x33mmR .357 Magnum S&W M27, Colt Python 10.8x33mmR .44-40 Winchester M1873 10.97x33mmR .44 Magnum S&W M29 "Dirty Harry" 11.2x32mm .44 Automag .44 Automag 11.43x23mm .45 ACP or .45 Auto Colt M1911A1, Thompson M1928A1 11.43x60mmR .45 Martini Martini-Henry Mk.I 11.56x33mmR .45 Colt Colt M1873 11.6x54mmR .45-70 Springfield Trapdoor, 1874 Gatling Gun 11.6x63.5mmB .458 Winchester Magnum Winchester M70 African 11.6x74mmB .460 Wetherby Magnum .460 Weatherby Mk.V 12.7x83mmR .50-140 Sharps Sharps M1874 "Buffalo Rifle" 12.7x99mmB .50 Browning .50 Cal M2HB 12.7x108mmB Type BZ DshK M38/46 (Russan Heavy MG) 13.9x22mmR .56/50 Spencer Spencer .56 (1st US-issue metal cart) 13.9x99mmB .55 Boys .55 Boys Mk.I 14.45x114mmB Type BS-41 PTRS-41, KPV 15.7x76mmR .600 Nitro Express .600 Nitro Double Rifle "Elephang Gun" The "Designation" follows the NATO standard for such things, and is simply the diameter of the projectile by the length of the cartridge case, both measured in millimeters. So, the .357 Magnum is 9mm in diameter, and the cartridge case is 33mm long. The letters at the end of the designation indicate the style of the rim at the base of the cartridge. No letter is a standard rimless cartridge as used in most modern designs (rimless cartridges feed better through belts and magazines). A "R" indicates a rimmed cartridge, which is a very old style and commonly found only in revolvers. "SR" indicates a semi-rimmed round; this is a compromise between the easier extraction of a rimmed case and the easier feeding of the rimless design. A "B" indicates a belted case, used on very powerful rounds to give the cartridge extra strength. And last (but not least) a "C" indicates a caseless round. > I also wonder about how ff&s handles recoil for these *large* rifles. FF&S computes recoil based on the muzzle energy of the round and the total mass of the gun (and a couple of other factors thrown in for good measure). Since these guns are quite heavy (even without the draft rules making them heavier than they would be otherwise), the recoil comes out fairly low, particularly considering how much damage they do. Then again, these large rifles are designed to be fired while stationary, from a bipod. Here is the rifle I promised earlier. Take the FF&S figures with a grain of salt, because I was using a draft of the rules; the final rules will probably do much better. To use this weapon in your games now, take the values from the "Real World" column. When you need information that's not there (like price in credits) refer over to the FF&S column. Note that the FF&S column includes information on a (hypothetical) TL-8 discarding sabot round which was never actually manufactured for this gun. This might be a particularly interesting twist on the gun; there's no reason why DS ammunition *shouldn't* work ... No longer do your TL-5, xenophobic natives have to cower in fear of Reformation Coalition backed Star Vikings. Have the local warlord call up a few squads of these "poor man's fusion guns". With Ball ammunition (locally producable at TL-5), they can penetrate TL-10 Battle Dress and any Combat Armor. With DS ammunition (a TL-8 item), these weapons have damage and penetration equal to (or better than, particularly at longer ranges) the FGMP-14 and FGMP-15 and can effectively defeat all forms of personal armor, as well as the side, deck, belly, and turret armor of the G-Carrier and the Grav Tank. Given their relative low cost, particularly when compared to their high-tech opponents Battle Dress (Cr220,000) and Fusion Gun (Cr54,000), these weapons are clearly very cost-effective. Example 5: 14.5mm Protivotankovoe Ruzh'yo obr 1941g (PTRS-41) Item FF&S Value "Real-World" Value (note 1) (all values taken from published Ball DS real-world data except as noted) I. Ammunition Tech Level: 5 USSR circa 1941 Caliber: 14.5mm 14.5mm Length: 146.7mm 114mm Type: Necked Necked, AP Incendiary Overall Length: 175.7mm ? Mass: 242.25g 201g Average Energy: 31007J 31017J Price: Cr12.1 Cr24.2 ? II. Weapon Design 1. Barrel Average Barrel: 147.5cm 139cm Actual Barrel: 139cm 139cm Type: Heavy Weight: 4.17kg ? Price: Cr1668 ? Actual Energy: 30123J 31017J Damage: 12 12 * 12 Penetration: 2-2-3 1-1-2 * 2-2-3 2. Receiver Type: Light Self-Loader Semi-Automatic Length: 95.5cm ? Mass: 30.123kg ? Price: Cr6024.6 ? 3. Stocks Type: Wooden Rifle Stock Wooden stocks, carrying Length: 25cm handles, and integral bipod. Mass: 1kg Price: Cr25 Barrel Len Mod: 0.9145 * 1 Close Range: 206.3m 247.6m * 229.0m 4. Feed System Type: Box Magazine (note 2) Internal Magazine, clip loaded Capacity: 5 5 Mass: 1.308kg ? Cost Cr1309 ? Loaded Mass: 2.519kg 1.193kg 5. Options ? Total Mass: 36.601kg (w/o bipod) 22.053kg (with bipod) ? Total Length: 259.5cm 213.4cm ? Total Price: Cr9026.6 ? Recoil: 5 * 5 Bulk: 17 * 14 b. Bipod Bipod Mass: 15.062 Bipod Cost: Cr200.6 Total Mass: 51.663kg 22.053kg Total Cost: Cr9227.2 Recoil: 3 * 3 * Gaming data computed from real-world values with FF&S formulae. Notes: 1 - Whenever two figures are given, the first is for ball (an option for Armor-Piercing Incendiary would have been nice) and the second is for the "high-tech" (TL-8) Discarding Sabot round. 2 - Figuring the internal magazine as a box magazine that's permanently attached to the weapon. I'm also using the grams to kilograms "fix" that I mentioned in my first weapon design. Comments: Yes, this really was a real gun. Originally designed as a man portable, anti-tank small arms rifle by the Soviets during WWII, the gun was quickly outclassed by the rapidly improving armor protection of German tanks. The cartridge lives on as the ammuntion for the TL-6 KPV machinegun (found on many Soviet armored vehicles and anti-aircraft defenses). The gas-operated action of this rifle (scaled down, of course) found its way into the SKS rifle. Tactical Considerations: The close range of this weapon exceeds the extreme range of every fusion gun except the FGMP-14 and -15, and the short range equals or exceeds the extreme range of any of the fusion guns. The best use of these weapons would be long-range fire at the attackers, from behind cover (preferably cover strong enough to resist an extreme-range fusion gun strike) or sniping from outside the range of their weapons. If this is impossible (and it frequently is), then a series protected positions likeley to suprise the enemy are good (around a corner in a corridor, for example). Game Use: This weapon (or rather, one using the "real world" stats and not the FF&S design, which is completely impractical) could be quite useful to anti-RC forces in the New Era. A relatively low-tech design, it is quite capable of being manufactured by many worlds in the Wilds. Although the DS ammunition is probably going to be considerably harder to produce, there will probably be a number of worlds equipped with it. As Star Viking activities expand, it is very likeley that traders operating in the wilds will find a demand for this type of weapon. Several adventure plotlines are possible around this weapon; one which suggests itself to me is probably obvious. The players (RCES or 'Lancers) attempt a smash-n-grab on some TL-5 to TL-7 dictator. They expect an easy time of it. Pull this one on your players after they've done two or three of the same type of missions in a row and have had a chance to get overconfident and complacent. Suprise them with the weapon; without the DS ammunition, it shouldn't be too deadly, but should (if employed well) be able to prevent the PCs from accomplishing some or all of their objectives. Drive home to them in a practical sort of way how difficult their lives would be if lots of worlds had them. Later developments in the campaign can involve efforts to stop free traders from spreading the guns (or the designs) around the area. Another one might have to do with discovering that someone is producing DS ammunition. [email removed] - ------------------------------------------------------------------------------ Science-Fiction Adventure In the Far Future