Welcome to episode #005 of the AR15 Podcast. I’m your host Jake Challand from Gun Guy Radio. This is THEE podcast about youuurrrr favorite black rifle! This show is for you; whether you’re building your first AR or you’ve been building ARs for years. There’s something we can all do to take our black rifle to the next level.
Joining me is Co-host Reed Snyder former Marine and full time Texan.
Main Topic: AR-15 Cool Factor
Brownell’s AR-15 Builder – Build your own cool looking AR-15 here
Jon: Thank you again for this podcast subject, however the explanation given about forgings is inaccurate. There are three basic configurations for aluminum used in the manufacture of AR lowers: forgings (strongest), billet (moderate), and cast (weakest).
Forgings: Almost all major manufacturers use aluminum forgings for their lowers. Due to the high cost of the machinery, only 5/6 foundries fabricate the forgings for all the AR’s made in America. A piece of red hot aluminum is put in between two dies and is smashed into shape by a very large (100 ton) hydraulic hammer. These raw forgings are then sent to a machine shop for further machining and processing. The forging process aligns the molecules in the aluminum grain structure to make a very strong finished product. (Note: All aircraft landing gears and highly stressed wing parts are manufactured this same way because of their strength.)
Billet: Billet is nothing more than flat plate or bar stock that is machined to finished configuration, cutting through all the molecular grain structure, thereby weakening it. There are only a couple of manufacturers, like Sun Devil, making billet lowers. Their benefit is that they can change configurations or modify tolerances with a few keystrokes on the computer. The material used is usually 6061 -T6, rather than the stronger 7075-T6 used in forgings.
Castings: This is what was given as being a forging (ie pouring aluminum into a mold, usually made from sand or ceramic media) in podcast #3. Castings got off to a bad start as being weak in the early years of aftermarket lowers, due to a very granular, easy to fracture molecular structure. Castings are generally used because they are cheap to produce and minimize additional machining required. Ruger now uses this method exclusively for their firearm actions, including the SR 556. They seem to have gotten it right, but most builders will still shy away from any cast uppers or lowers for strength reasons.
95% of production lowers are strong forgings produced by 5 or 6 foundries in America and are sold to only 11-18 machine shops. They are then sold to the actual AR manufactures with the manufacturer’s name imprinted on the lower.
You have a great podcast and forum with a lot of listeners. I’m sure you would like the correct info out there. Just thought I’d bring this to your attention, but know you will probably want to follow up with research of your own. You will probably want to fact check on future podcasts, because many of your listeners are taking what you are saying as accurate fact.
Looking forward to more good stuff!
Lane Douglas: In episode 015 of GGR you talked about building an AR. Do you have a source for the lower casting, the part with the serial number, that will sell without first registering it through an FFL? Brownells will not sell without shipping to my FFL, ditto for a few others I have checked. I am ok with the process, just trying to avoid the $10 back ground fee, and $25 transfer fee that my FFL charges.