Mechanical Engineer for a large equipment manufacturer.
11 year US Army Veteran. 5 years active duty on Tanks- M1A1. 5 km, 1st round kills dozens of times. Most with the degraded mode optics. (simple scope with bullet drop compensator)
I’ve taken all of the police tactical training that I can take without being a cop.
Married to a lawyer. HA! Haven’t won an argument in 20 years!

I have been building and procuring firearms for many years. The engineering degree helps a great deal when understanding the science behind weapons and ammunition. I advise friends how to build their own and buy their own, but I don’t sell what I’ve built.
Bolted joints and gas pressure science is one of my specialties, My advice to you- is DO NOT WING IT! Those torque values and max gas pressure on your barrel is there for a reason. There is always a factor of safety, but unless you understand and use the science and math behind it- you are in danger. It could be you life, or the life of the person (or kid) standing next to you.