For modding reference, here is a quick overview of a new "simpler" shotgun grip design i came up with for the Longshot, which i will refer to as the PVC Shotgun Grip.
It is based on a similar concept as my Polycarbonate Shotgun Grip design, but instead of using polycarbonate, this new design is made from just PVC pipes instead
Imho, its not going to win any prizes for looks (kinda reminiscent of the fallout/mad max "post-apocalyptic" style though), but its functional and it works. :)
Modders who are already familiar with making shotgun grips should be able to easily figure out how its constructed just by checking out the following photos.
The PVC grip uses a 10cm length of 65mm SingaPlastics PVC pipe (thinwall version / 70mm ID) and it is heat shaped (i simply put it into hot water to soften the PVC until it becomes an oval shape of 60mm tall and 80mm wide), so that the grip can be fitted on the Longshot without requiring any further modification to the casing. Channels are cut into the grip to allow it to slide along the Longshot's existing groove at the bottom part of the front section.
Note that the oval grip shape is designed to create the extra space to fit around the Longshot's existing bipod mounts (otherwise the casing mounts will need to be cut away to fit it).
The grip arms are made of 34cm lengths of 13mm SingaPlastics PVC pipe, and they are attached on to the grip with M4 bolts. The spacing between the arms and grip are supported with 2 x M4 nuts per bolt which act as standoffs.
I used a 4" length 4.5mm diameter bolt and nut, along with nylon spacers to thread through the original priming handle points and secure the arms to the bolt sled.
So far, this grip design has been field tested to be strong enough for use with most modded Longshots (successfully tested with up to 20kg load springs), and the oval grip shape is ergonomic and comfortable for users too.
There is no drilling or cutting of the original Longshot casing required, and the grip can be easily transferred between Longshot units.
Overall, its a relatively simple build method and an alternative for modders who prefer using PVC pipe materials for their mods. :)