Armor

[Atgxtg]

Anyone got any good soruce for bullet armor penetration? I'm working on some armor tables and would like some real values to compare it to.

[Layec]

For body armor, there is of course the NIJ Standards for Body Armor. I found them here.

[Atgxtg]

Thanks for the NIJ tables.

I'm thinking more in terms of thickness penetrated. I got a table that gives Armor rating based on thickness (and material) that is a fairly good fit for the data points given in the BRP core book (10cm glass, 120cm concrete, 30cm steel, etc.)and I wanted to see how much fine tuning it needed to get it to match up right with the the firearms. I want want to make sure that a weapon that can penetrate a given type of cover, it can do so in BRP.

What I got can give an AP rating based on thickness and an item's material strength (usually tensile strength, but it can work with Brinell hardness and other such numbers for tank armor). It also can be used for thinks like submarine dive depth using yield strength or compression strength.

Edited August 30, 2012 by Atgxtg

[rleduc]

I looked around and couldn't find my old reprints -- but what you want to do (in case you don't know) is google "armour materials terminal ballistics" or the like. The key buzz word there is "terminal ballistics". There is a long wiki article on terminal ballistics which is where you would want to start.

[Atgxtg]

Thanks. I've found a few things such as values for a 30-06, 12.7mm ans 20mm, and practically every tank gun from WWII.

Most terminal ballsitics searches tend to focus on pentration in flesh/ballstic gel.

There have been a few difficlutes translating the data into BRP terms , too, as you of all people are probably all too aware. While it is possible to come up with several formulas that fit the data points for the samll arms, they don't match up with what little artillery listed in the BRP core book. And then, matching the BRP damage up to armor thickness is another obstacle. I've tried several different approaches, and the formulas that work best for damage, don't work for armor. And I'vebeen trying to tie it all in with a smoothed progression damage bonus table to once and for all get damage on the same page for everything. Unfortunately, every type of damage in BRP uses it's own progression curve. Firearms seem to use a base2 progression, while (STR+SIZ) use a base4 progression, heat uses a straight linerar progression (+1D6 per 100c), falling damage increases with distance, which completely seperates it from velocity and force .

I'm starting to decide just how much I'm willing to divert from the BRP core rules to make things work. One thing that I do thing will help will be a damage Class system similar to your risk system in effect (in not exactly the same in value or dice). THe risk method solves the problem of the increasing power of 1 point of damage at the high end. A 51 point hit though 50 points or tank armor is probably a couple of million Joules, and should do more than 1 point of damage to the tank. The risk method solves that problem. I think I got a simple way to realstically get more than a 1 point reduction out of armor, too.

[rleduc]

Yeah -- I.ve been there. For me, at the end of the day, the question was how important to me was it to have a grand unified damage system that scaled in all directions, gave a first approximation to the real world, and was playable? (By the way, experience has taught me that all systems that require taking the log of a die roll are bad :-) ) My answer was to not worry about scaling -- for Rubble and Ruin it was so rare that anyone went outside of the firearms scale that it was not useful to me to worry about larger weapons. Obviously, I don't have a final answer -- but I wish you luck.

[Atgxtg]

Yeah, that's exactly the situatrion, and thanks.

I can come up with something playable and scalable, but it doesn't quite match up with the standard BRP values. Close,m but not quite. Basically, something like x4J is worth +5 to damage, scales beautfiy, is very playable, but doesn't quite match up with BRP. For example: 500J =5, 2000J =10, 8000J =15, 16kJ=20, 64kJ=25, 256kJ=30, 1MJ =35, 4MJ= 40, 16MJ= 45, 64MJ= 50, 256MJ=55,etc.It works, but is a little low at the high end, compared to BRP.

BTW< I hope your night right about the log thing. I got an RPG idea in the works that uses LOGs for everything. The LOG of the number is the amount of D20s rolled, while the deciaml portion is the add.

Edited September 4, 2012 by Atgxtg