3D printed plasma rifle: what dimensions?

[ConsummatePro]

I'm thinking of 3D printing a Plasma rifle. I found a decent model on Thingiverse at https://www.thingiverse.com/thing:2379808

The posted model claims to be full scale (635mm length) so if I just scale to 50% would it be the proper size for our T800's?

When sized down, the length is about 316 mm (12.4"). It looks to me like the grip is too small in this model when sized down (about 28 mm on the front edge of the grip to the trigger guard, or about 34mm from the posterior aspect of the grip to the barrel of the gun.

Can someone tell me the dimensions of their plasma rifle?