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Old 04-02-2017, 09:07 AM   #21
DouglasCole
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Default Re: GURPS ULTRATECH ballistics?

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Thanks for the comments Doug. I kind of knew that any time you have a final damage value that is based on Mass times velocity Squared, I knew that this would be a function value where you fill in 1 value, the remainder would automatically spit out.

My next post is going to be based on some conjecture, and I will use the historical data for a 7.5mm round gun from the past designed in 1883, using black powder (presumably) that was used until 1903 in the Swiss army. Presumably, that round had satisfactory characteristics for flight, that it was worth retaining. Its mass was 110 grains (range given is 102 to 110, so let's use the upper for this example).
I no longer have the simple spreadsheet I sent you - can you email it back to me?
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Old 04-02-2017, 09:09 AM   #22
DouglasCole
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Pretty sure that doesn't work once the expansion rate is significant relative to the speed of sound in the gas; ideal gas law is for equilibrium.
Pretty sure I didn't care. It produces reasonable values and is easily integrated into a closed-form solution.
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Old 04-02-2017, 09:15 AM   #23
DouglasCole
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So, anyone? How does one calculate the recoil statistic? Is it a factor of barrel length plus weapon weight or something along those lines?
You'll have to talk to David and Hans about that. Rcl in GURPS is only partly based on pure physics; there seems to be an ergonomics component to it as well. A base "how much does the weapon kick" is probably based on the momentum of the bullet and powder divided by the mass of the weapon firing it. And even then there's likely some fiddle. The basic question Rcl answers is "how much does the weapon jump around in rapid fire?"
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Old 04-02-2017, 10:35 AM   #24
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I no longer have the simple spreadsheet I sent you - can you email it back to me?
Turns out, I still have your email after all!

Sent for you to enjoy. If you want the database on cartridges - in excel of course, it is yours for the asking. Also, my adventure guns file for GCA is available should you desire it.

As for calculating the recoil statistic - I'd probably use the ME Joules value on the premise that what goes forward, must also go backwards.

Twice the kick going back might cause maybe a +1 or +2 recoil modifier if using the same concept as the sensor rules from GURPS. A x10 modifier might be a +6 recoil? I suspect I'll have to try to build a database of guns already detailed, figure the ME in Joules values for those, put *** around damage values that don't match the spreadsheet formulas - and see if there is some sort of mathematical progression involved that ties in ME and mass and possibly even length of weapon. :)

Something to do later on to keep me occupied I guess.

Last edited by hal; 04-02-2017 at 11:25 AM.
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Old 04-02-2017, 11:45 AM   #25
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Now I do not know Mr. Cole personally, but would expect him to try and use a table on B550 to calculate Rcl somehow... =)
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Old 04-02-2017, 03:59 PM   #26
DouglasCole
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Now I do not know Mr. Cole personally, but would expect him to try and use a table on B550 to calculate Rcl somehow... =)
I approve of your ideas and wish to subscribe to your newsletter.
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Old 04-02-2017, 04:35 PM   #27
hal
 
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I approve of your ideas and wish to subscribe to your newsletter.
Douglas Cole, a Hard Working American with Ideas. This message brought to you from the Committee to Elect Doug to be the Author of GURPS GUNSMITH, an article that SJGames does not know it wants.

Paid for by the Committee.

;)
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Old 04-02-2017, 07:54 PM   #28
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Douglas Cole, a Hard Working American with Ideas. This message brought to you from the Committee to Elect Doug to be the Author of GURPS GUNSMITH, an article that SJGames does not know it wants.

Paid for by the Committee.

;)
Doug is also a strong candidate for the title of World's Busiest Human. :)

Going through this would probably only give you part of everything he's involved with......

https://gamingballistic.com/2017/04/...pdate-april-1/

So temper your hopes with realism.
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Old 04-02-2017, 09:03 PM   #29
hal
 
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Default Re: GURPS ULTRATECH ballistics?

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Doug is also a strong candidate for the title of World's Busiest Human. :)

Going through this would probably only give you part of everything he's involved with......

https://gamingballistic.com/2017/04/...pdate-april-1/

So temper your hopes with realism.
In all honesty - I did that last bit as a tongue in cheek kind of thing. While I have mentioned it to him in private, I know too, that the center of the universe isn't set on me - which is a good thing at the moment.

When Doug made the comment he did about the blog, I could hear the voice "This is Douglas, and I approve of this commentary - NOT"

;)

So, will the world come to a stop without gun creation rules? Not hardly. I have GUNS GUNS GUNS if I really set my mind to it. Alternatively, I can go back to my old standby of AFTERMATH, the very first rules set that I looked at for GUN design. This was back in the day before GURPS HIGH TECH first edition came out. Today, my best friend commented to me that he wanted to see an AFTERMATH style campaign again. We were talking about the first campaign we ever ran, which was, late 1986 through 1987, and realized "holy crap* That was THIRTY YEARS AGO!" So, he wants a shot at AFTER THE END. Any gun that isn't in the GURPS material, I'll just have to create for myself, which is why I've got sufficient materials on guns up to about 2000 AD. Once I take the time to crunch the numbers using the Muzzle energy in Joules and correlating them to the values already given in GURPS HIGH TECH, I might be able to do the following:

Correlate real world data with GURPS guns and come up with my own GURPSIFICATIONS of real world guns.

Correleate the gun design system that Greg Porter wrote into the GURPS 4e system instead of GURPS 3e (which Greg Porter included in his book). What I never bothered to do is see what cartridges that have already been published and compare them against real world data with the game data. I've already found one discrepancy with regards to the H&K 11 stats in MODERN FIREPOWER matching the damage specs in GURPS HIGH TECH and the formula suggesting that it really only should be 3d+1 (or something to that effect). But you know what? I don't have a fetish for being anal retentive about all the details. ;)

Granted, knowing how much filler is in a warhead is probably TOO much details, it helped when I wanted to convert bombs from TWILIGHT 2000 for use with GURPS, etc. (or did I use my reference books to figure out real world data - Dang, I have forgotten!)

Someday, it would be fun to run a GURPS TWILIGHT 2000 campaign, or perhaps another aftermath. Pain in the butt that my buddy is? He said "Watch REVOLUTION on Netflix". That seems to come under a secondary heading for X-Files kind of thing after watching two episodes thus far.

An well, I'm rambling. I probably should try to catch up on some sleep.
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Old 04-03-2017, 06:44 AM   #30
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Default Re: GURPS ULTRATECH ballistics?

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I've already found one discrepancy with regards to the H&K 11 stats in MODERN FIREPOWER matching the damage specs in GURPS HIGH TECH and the formula suggesting that it really only should be 3d+1 (or something to that effect). But you know what? I don't have a fetish for being anal retentive about all the details. ;)
Bear in mind that Doug's unofficial formula is reverse-engineered and does diverge in certain assumptions from the one developed by David Pulver (math) and me (fine-tuning and reality checking against hundreds of data points) ages ago, I think in 2002 or 2003 or so. This was used for the weapon stats in all recent High-Tech books. I find it difficult to see how you can see a discrepancy when you're not using the official formula. Yeah, I know, the formula itself is unpublished, but the results aren't. They are in all my books, which are internally consistant.

Cheers

HANS
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