M58 Shotgun To Sniper Rifle Conversion Kit by GoldenLampshade

Last crawled date: 3 years ago

A kit to convert a Double Eagle M58 (A or B) to a sniper rifle. It adds a slide bolt style reloading handle, a mount for a stock, a longer steel barrel with optional threaded end and 6 total rails for scope, bipod, laser dot, torch etc.
You will need a 3/4 inch (19.05mm) steel tube with 1.5mm walls, cut to around 350mm.
You will need to cut the existing steel tube (the one that the pump action grip slides over) to about 240mm and put the leftover bit inside the buffer tube for some extra weight.
You will need to bend the steel rod that was connected to the pump action grip that goes into the body of the gun at a 90 degree angle 55mm from the exposed end.
You will need 5 dome headed self tapping screws with 3.5mm thread and heads no wider than 7.5mm. Anything between 15 and 25mm total length should be fine. I used 19mm.
You will need to find a stock and any rail/ barrel mounted attachments from elsewhere. I did not design these and they are not included. The mounts are all standard sizes so you can put whatever you want on them.
I did not design the pistol grip, I found it on Grabcad and modified it a bit to make it more comfortable and suitable for my needs. It looks like a standard AR15 grip but it isn't, and you cannot use an AR15 grip from elsewhere.
Some parts are designed to be a tolerance fit and will need tapping into place.
There are two files for the barrel end, one threaded for a suppressor or other attachment and one not. You can use either depending on your needs.
All files are orientated the way that they should be printed, you do not need to rotate them in the slicer program.
I recommend printing in PETG or ABS, with an infill of at least 40% and supports enabled for angles over 80 degrees. Parts with very little surface area touching the build plate should be printed with a brim.
I printed the pistol grip using Cura's 'Fuzzy Skin' mode, it worked well.
To secure the scope rail better I added a ziptie to the back, as seen in the pictures. This may not be necessary but I feel it is worth mentioning.