Page 1 of 1

Receiver material/project build advice

Posted: Sat May 21, 2016 7:56 pm
by Jonathanw
Hello,

I am currently working on a project gun, I have figured out my conceptual design. Now I'm working on figuring out which material would provide the best strength for my build while still being workable in available milling machines that I will have access to.

So the gun receiver is similar to an AR design, in the sense that a lot of the pressure from shooting the round is focused on the bolt, carrier, barrel, locking lugs, which means the upper receiver shell can be aluminum and not go KA-BOOM.
I would like to use 7075 aluminum however i can not weld in my trunnion so I was wondering can you rivet inplace a steel or aluminum trunnion from a aluminum receiver wall? Kinda like how am AK trunnion is riveted in place.

6061 is weldable however it is almost half the strength of 7075 so I don't think it is wise to use that material for the upper receiver . A good candidate for the lower however.

Any advice is appropriated, I am new to learning about studying metals so correct any information I may be wrong about.

Re: Receiver material/project build advice

Posted: Sat May 21, 2016 9:06 pm
by Rentprop1
think steel trunion pinned in place, across alum frame ?? , recessed lugs in the aluminum shell where its movement is very limited , slipped in from top or bottom ??

Re: Receiver material/project build advice

Posted: Sat May 21, 2016 9:34 pm
by Jonathanw
Rentprop1 wrote:think steel trunion pinned in place, across alum frame ?? , recessed lugs in the aluminum shell where its movement is very limited , slipped in from top or bottom ??
Are those suggestions or questions [smilie=011.gif]

If I'm reading it correctly, your idea of how to secure the receiver and trunnion seems like a great way to do it. I just want to make sure the rivets/pins won't crack or damage the receiver

Re: Receiver material/project build advice

Posted: Sun May 22, 2016 7:34 am
by Rentprop1
Steel lugs screwed to the inside of an aluminum shotgun receiver usually don't break ?? A channel or recess would strengthen it and the pins merely hold it from falling out ....this the slip in channel

Re: Receiver material/project build advice

Posted: Fri May 27, 2016 7:41 am
by Jonathanw
Anyone know What material is the ar15 gas key made of?

Re: Receiver material/project build advice

Posted: Fri May 27, 2016 8:24 am
by MomentArms
4140 28-32RC

Re: Receiver material/project build advice

Posted: Fri May 27, 2016 9:29 am
by Jonathanw
MomentArms wrote:4140 28-32RC
Thank you