Steve Jackson Games - Site Navigation
Home General Info Follow Us Search Illuminator Store Forums What's New Other Games Ogre GURPS Munchkin Our Games: Home

Go Back   Steve Jackson Games Forums > Roleplaying > GURPS

Reply
 
Thread Tools Display Modes
Old 04-07-2017, 11:22 AM   #1
LokRobster
 
LokRobster's Avatar
 
Join Date: Mar 2005
Location: Republic of Texas; FOS
Default [High-Tech] Airbow: Compressed-Air Arrow Launcher (stats?)

I ran across an interesting weapon today, made by Crosman: The Airbow. They refer to it as a Pre-Charged Pneumatic (PCP) bow.

It looks like a TL8 bullpup assault rifle with an arrow sticking out of it instead of a barrel, and a thick shotgun-magazine-looking tube sticking out under the arrow - presumably the air chamber.

Stating it up should be fairly straightforward.

The Manufacturer claims 450FPS for the special-made arrows, with standard broadhead arrowheads. The on-board chamber holds 3000psi with volume enough for 8 shots before charging (with a compress gas cylinder or a hand-pump). RoF and reload claims "Eight shots in the time it takes for a crossbow to shoot three", so, about 2 seconds to reload?

Length is 33.5" and weight 7lbs.

How does this look for stats?

TL Weapon - Damage --- Acc - Range -- Weight - RoF Shots - ST Bulk Cost LC
8 -- Airbow -- thr+4 imp - 4 - x20/x25 - 7/0.1 ---- 1 -- 1(2?)- 6† -4 --$900 3
Notes[1- After 8 shots must be recharged with pressured air: 10 seconds for tank, 5 minutes for hand-pump] <--- times seem about right?

What ST rating would "450FPS" most closely represent? I am guessing The Deadly Spring would tell me.

Damage/Range depending...
ST10 1d+2 imp, Range 200/250
ST11 1d+3 imp, Range 220/275
ST13 1d+4 imp, Range 260/325
ST15 1d+5 imp, Range 300/375
(those numbers need a dice+adds conversion? I can't place it right off, but i seem to remember 1d+4 = 2d?)

Comparison: The Basic Crossbow
TL Weapon Damage Acc Range Weight RoF Shots Cost ST Bulk
2 Crossbow thr+4 imp 4 x20/x25 6/0.06 1 1(4) $150 7† -6


I figured min ST as 6 because it really doesn't take any effort at all to cock/ready the thing - the mechanism seems to be just metering in the pre-regulated air for 1 shot at a time, like opening a valve.
__________________
Our rarely updated CarWars blog & Hotwheel conversion tutorial: North Texas Autoduel Association

Last edited by LokRobster; 04-07-2017 at 11:28 AM. Reason: stat-blocs! wheee!
LokRobster is offline   Reply With Quote
Old 04-08-2017, 09:22 AM   #2
Varyon
 
Join Date: Jun 2013
Default Re: [High-Tech] Airbow: Compressed-Air Arrow Launcher (stats?)

375 grains is 0.0243 kg, and 450 fps is 137.16 m/s, for around 230 J. At the cinematic scale, that's 8.64 damage, or 2d+1. At the realistic scale, that's 6 damage, or 2d-1. Using the range equation from The Deadly Spring (which is also where the damage is calculated from), we get a maximum range of 1460 yards. Typical modern arrows are apparently between 9/32 and 5/16 inches in diameter, for a 1/2D of between 400 and 500 yards. They fail to note what sort of crossbow they're basing things off of, but I'd assume one that just uses arm strength alone. They may have left off the time to draw and place the arrow (one second, negated with Fast Draw), but either way the quoted reload rate implies about a 2 second reload, as you note. The weapon's total length is essentially the same as an M4, so Bulk -4, as you note. 2" groups at 50 yards implies a maximum skill of 26 or 27, for Acc 3. Overall, something like this:
Code:
TL	Weapon	Damage		Acc	Range		Weight	RoF	Shots	ST	Bulk	Cost
8	Airbow	2d-1 imp	3	450/1450	7	1	1(2)	8†	-4	$700
I left off LC as I wasn't certain. Cost was based on what current $999 would cost in 2000 (which I think is what GURPS dollars are roughly equivalent to), and I went with higher MinST than you because I felt comfortably using the weapon should require it to fall within 1/2 BL (rather than falling within BL, as you opted for). The above are meant to be realistic statistics - in a cinematic game, 2d+1 imp for damage and Acc 5 are probably appropriate (bows in general have higher damage and accuracy in cinematic games). In fact, the weapon's actual Acc may only be 2, with Fine (Balanced) arrows being used by default. Using broadheads would probably mess with damage and range a bit (I think the quoted statistics are for the field tips; see The Deadly Spring to figure out what replacing that with a broadhead would do).

Last edited by Varyon; 04-08-2017 at 09:52 AM.
Varyon is offline   Reply With Quote
Old 04-08-2017, 10:44 AM   #3
Fred Brackin
 
Join Date: Aug 2007
Default Re: [High-Tech] Airbow: Compressed-Air Arrow Launcher (stats?)

Quote:
Originally Posted by Varyon View Post
375 grains is 0.0243 kg,).
Hrm, those are very lightweight arrows. The Gurps standard would come to 700 grains and wooden arrows from my long ago youth were heavier than that.

Maybe this thing doesn't stress arrows the way a real bow does but a rule of thumb for hunting arrows I found a few years ago suggested 10 to 15 grains per lb of pull.
__________________
Fred Brackin
Fred Brackin is offline   Reply With Quote
Reply

Tags
airbow, bow, crossbow, high tech, ranged

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Fnords are Off
[IMG] code is Off
HTML code is Off

Forum Jump


All times are GMT -6. The time now is 12:55 PM.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2018, vBulletin Solutions, Inc.