Proposed change for range affect on damage

[Desert Mariner]

I just want to point out that in the Berger Bullets ballistics calcultator, you still need to select the curve set. Looking at the presets, the pistol rounds use G1 and the rifle rounds use G7.

Keeping it simple, the answer is yes. But bear in mind G7 actually is dependent on the bullet (7.5 degree BT) not the weapon so in some instances a rifle may need to use G1.

In my calculations, if the BC is clearly labeled by the manufacturer as G7 I used it. If there was any doubt (i.e. only one listed), I assumed it was a G1 BC. Luckily, most manufacturers (S&B included) list both and G1 works in a pinch as the two curves usually run close to each other.

[Desert Mariner]

My apologies, the original PDF I posted was an older version. This one identifies the type of BC used (G1 or G7) and includes photos for most of the weapons (Stoner photos seem to be few and far between).

You'll note that the 5.56 weapon's E-factors come out lower than those listed in TM-1-1. I don't know if this is an error in the 4E figures or if I just haven't found the right cartridge to bump up V0.

I've given a similar treatment to numerous weapons for possible use in the equipment updates mentioned in 4E. They range from Sig P320s in 4 sizes and calibers to the FN SCAR series, HK UMPs and USPs plus some .45 Colt revolvers and lever guns for fun.

EDIT - added the attachment that somehow didn't upload the first time

[nuke11]

You'll note that the 5.56 weapon's E-factors come out lower than those listed in TM-1-1. I don't know if this is an error in the 4E figures or if I just haven't found the right cartridge to bump up V0.

Try using Federal American Eagle .223 55 grain and 62 grain.

55 grain: BC .269
62 grain: BC .307

[nuke11]

My apologies, the original PDF I posted was an older version. This one identifies the type of BC used (G1 or G7) and includes photos for most of the weapons (Stoner photos seem to be few and far between).

You'll note that the 5.56 weapon's E-factors come out lower than those listed in TM-1-1. I don't know if this is an error in the 4E figures or if I just haven't found the right cartridge to bump up V0.

I've given a similar treatment to numerous weapons for possible use in the equipment updates mentioned in 4E. They range from Sig P320s in 4 sizes and calibers to the FN SCAR series, HK UMPs and USPs plus some .45 Colt revolvers and lever guns for fun.

EDIT - added the attachment that somehow didn't upload the first time

How much nitpicking do you want

Example. Barrett M82A1A : "metallic sights" could read better as iron sights. They are technically metallic, but I've never heard it referred to as metallic sights.

And I see what you noted as to E-factors. Most of the time when I'm doing a range card for my players I would use the stated MV of the firearm as the starting value and use the adjust charts from the software as the range card. For firearms I couldn't find a value I would use some charts found on the internet for general lengths to MV for different types of ammunition.

[Desert Mariner]

Try using Federal American Eagle .223 55 grain and 62 grain.

55 grain: BC .269
62 grain: BC .307

Without rounding, even these calculate lower than the E=15 listed in TM 1-1:

55gr FMJ @987mps comes to E=14.5
62gr FMJBT @920mps comes to E=13.5

I'd have to treat the BC as G1 since they don't specify and that would align with other 5.56 rounds.

The S&B 5.56 rounds I've checked include (these BCs are all G7):
55gr FMJ @1006mps BC=0.143 E=14.8
62gr DIM @945mps BC=0.143 E=13.9
63gr Tracer @915mps BC=0.143 E=13.4
69gr HPBT @920mps BC=0.148 E=13.5

E-factors shown calculated based on listed MV of cartridge, they will vary when barrel length of actual weapon is included.

Side note: I have been attempting to limit the number of ammo producers in keeping with the Project's need for secrecy and to simplify logistics.

[Desert Mariner]

How much nitpicking do you want


And I see what you noted as to E-factors. Most of the time when I'm doing a range card for my players I would use the stated MV of the firearm as the starting value and use the adjust charts from the software as the range card. For firearms I couldn't find a value I would use some charts found on the internet for general lengths to MV for different types of ammunition.

What I've done thus far is take the MV from the cartridge manufacturer and compare their test barrel length to the weapon's barrel. I then adjust the MV for the weapon by +/- 25fps per inch difference. this is a rule of thumb I was taught years ago but I have seen a figure as high as 50fps/inch in some forums.

[Desert Mariner]

Ive often wondered about the E-factor calculation itself. Is velocity and diameter the best indicator of ballistic damage Rules state oeProjectiles cause damage by virtue of the energy transferred into the target. So why not utilize the projectiles energy (E=0.5*m*v^2) [m=bullet mass in grains; v=velocity] as a starting point to determine E-factor Granted I have no idea how youd scale the result to fit the current BP/damage system.

[nuke11]

Ive often wondered about the E-factor calculation itself. Is velocity and diameter the best indicator of ballistic damage Rules state oeProjectiles cause damage by virtue of the energy transferred into the target. So why not utilize the projectiles energy (E=0.5*m*v^2) [m=bullet mass in grains; v=velocity] as a starting point to determine E-factor Granted I have no idea how youd scale the result to fit the current BP/damage system.

What we may want to have a look at is Kevin Dockery's update to the damage system he created for TMP. That system can be found here on my website http://www.thesupplybunker.net/Morrow/damage_system.zip

This was going to be included in a revision of the rules at some point, but didn't as we know.

I really haven't looked at it in years, to see what it was going to improve.

[Desert Mariner]

I think I'm happy it wasn't implemented. That is one complicated set of calcs. Probably way beyond the "average" gamer, especially today's button mashers.

[mmartin798]

Ive often wondered about the E-factor calculation itself. Is velocity and diameter the best indicator of ballistic damage Rules state oeProjectiles cause damage by virtue of the energy transferred into the target. So why not utilize the projectiles energy (E=0.5*m*v^2) [m=bullet mass in grains; v=velocity] as a starting point to determine E-factor Granted I have no idea how youd scale the result to fit the current BP/damage system.

The key here is energy transferred to the target. It is possible for a higher energy round to pass through a soft target and leave a smaller permanent wound track than a smaller lower energy round which expels all its energy into the target leaving a larger wound track.

[Desert Mariner]

The key here is energy transferred to the target. It is possible for a higher energy round to pass through a soft target and leave a smaller permanent wound track than a smaller lower energy round which expels all its energy into the target leaving a larger wound track.

I get that, but I think using energy (which includes velocity) and diameter (or cross section) rather than just velocity would have yielded a more realistic figure. However, after looking over the SOJ damage rules I see that route becomes very complicated.

[Desert Mariner]

Nice, I like them.

The only problem I see is the name of the Uzi carried over from the book. The Uzi No2 Mk B was a civilian version with a 16' barrel imported into the US from 1983 to 1989 and most where semi-auto only. It is not what would be considered "cool" to have in TMP as a player. Just the Name of Uzi is fine.

Duly noted regarding the Uzi. The attached is my current SMG/PDW line-up. Original 4E weapons have an orange header for clarity. I have separate files for MGs, Pistols & Revolvers, Rifles & Carbines and Shotguns (00 buck only thus far).

[mmartin798]

I have been looking for some terminal ballistics data for shotguns. This is the best-recorded results with well-documented methods that I have seen thus far. It is a good starting place.

http://www.brassfetcher.com/Shotguns/Maximum%20Effective%20Range/Buckshot.html

[Desert Mariner]

Another site that helps with shotgun shot ballistics:

http://www.ctmuzzleloaders.com/ctml_experiments/shot-ballistics/shot-ballistics.html

[mmartin798]

Duly noted regarding the Uzi. The attached is my current SMG/PDW line-up. Original 4E weapons have an orange header for clarity. I have separate files for MGs, Pistols & Revolvers, Rifles & Carbines and Shotguns (00 buck only thus far).

I just compared my P90 stats to yours and found a discrepancy on our E-Factors. I did some research and I think I found the source. The muzzle velocity you used, according to S&B's datasheet, was based on a 4.75" barrel. That is the length of the FN Five-seveN. The P90 has a 16.04" barrel. Looking at the specs for the SS197SR, fired from the Five-seveN has the same velocity as the S&B round. Assuming that both rounds perform similarly, fired from the P90 would have a muzzle velocity of 2100 f/s or 640 m/s. That would increase your E-Factor to 9.

The biggest source of the discrepancy though is the choice of the round. I assume the Project has access to restricted rounds like the SS190. That is what give me an E-Factor of 11.