Or at least what I think it would look like.
I could find very little info on this weapon system in Wikipedia. In a way this made it easier, and harder to design.
First I wanted to stick to TL-8 and use only FF+S-1. I ended up using both FF+S-1 and 2 and had to add a few items from TL-9.
Assumptions:
1: This is a spin/fin stabilised grenade. I actually read one article where it was called a "sniper rifle"
2: The range of 500 meters is Medium range making short range 250 meters.
3. The weapon's length is app 75cm. I found a picture of a soldier firing the weapon at Aberdeen and took a guess.
4. Took company PR at face value for a "state of the art" thermal image. Used TL-9 for the HRT and Laser RF.
The Rules I Creatively Avoided (Trashed) and why
1: In FFA+S-2 You are allowed to use "advanced materials" to lower the weight of a weapon. I did! At TL-8 you can lower the weight of the barrel and receiver by increasing the price. Wt x75% Price: Cr x5
2: The max barrel length of a G-Launcher is 10x the cal in cm. In this case 25cm I used 32.5cm for the length. This combined with #3 is the only way I could reach the incredible range of 250meters.
3: When figuring the range I doubled the final figure. Here I looked up the rules for a smooth-bore shotgun in the rifle rules Pg 96 FF+S-1, as I figured the grenade had to be stabilised in flight. Here I reasoned the shotgun slug/grenade was not stabilised in flight and received a 0.5 penalty as a result.
4: the HRT sight is half the size of the smallest one in FF+S-1. It weights 1kg now, its battery, weights 1 kg.
5: For a Laser RF, I just used the Laser Sight and bumped the Range to 250m.
6: The price of the grenade is "real world" not Traveller. sorry I just have no way of translating.
XM25 Individual Airburst Weapon System
TL: 8+
Ammo: 2.5cm Grenades
Weapon Length: 50cm
Weapon Weight: 6.2875kg
Weapon Price: Cr 4198
Mag Wt: 0.936kg loaded/ 0.486kg empty
Mag Price: C 5
Ammo Price: Cr 24 (HE-AB)
Ammo Wt: 90 grams
Features: Advanced (TL-9) 150m HRT with 4x zoom, TL-8 2x Optic sight
250m TL-9 Laser RF, Shock Absorbing Bullpup Stock
Round ROF Range IFR Damage Pen Val Bulk Recoil
HE-AB SA 250 NA C:1,B:5 Nil 3 1
I assume that the HE and HEAP rounds already in Traveller could be fired from this weapon. They would just not receive the range and barrel bonuses I gave the stabilized grenades.
Roger