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AR lower receivers - a question

Discussion in 'Firearms' started by JABECmfg, Aug 14, 2013.

  1. Yes, billet is the way to go!

    2 vote(s)
  2. Maybe in some ways, but not enough to justify paying more for one.

    2 vote(s)
  3. No, they are the same thing in the end.

    2 vote(s)
  4. No, I prefer forged lowers.

    3 vote(s)
  5. I don't know, but I'd really like to learn more about it.

    4 vote(s)
  6. Don't know, don't care - I want something with a wicked cool Zombie Slayer logo on it!

    2 vote(s)
  7. Irrelevant - I am loyal to a particular brand.

    0 vote(s)
  8. Holy cow, lower receivers in stock? I'm buying it!

    1 vote(s)
Multiple votes are allowed.
  1. JABECmfg

    JABECmfg multi-useless Site Supporter

    I'd like to know what people think about AR lowers machined from a solid piece of aluminum, compared to those finished from forgings. Ergo, I've created this poll to see what the monkeys around here think, and to encourage discussion on the subject.

    Also, I want to thank everyone in advance for their answers - I'm looking forward to the responses!

    Thanks also to @Airtime for a post yesterday about lower receivers, as it got me started thinking on the subject. I wouldn't have thought about it otherwise, so a thank you is in order.

    Let's hear some thoughts on the subject, monkeys! Is billet better than forged? Why or why not?
  2. DarkLight

    DarkLight I self identify as a Blackhawk Attack Helicopter! Site Supporter

    @JABECmfg - This probably doesn't answer your question but my question to you may be more important than the forged/billet question...which in many respects is almost purely subjective (given the differences between the two).

    What is the lower MADE out of, regardless of how much machining had to be done (because as I'm sure you're aware, even a forged lower still needs machining). 7075-T6 is going to be much "stronger" in almost every way (in most ways by a factor of 2).

    I suggest you hit the following site since it goes through just about everything with a VERY unbiased eye.
    Machined Versus Forged and 6061-T6 Versus 7075-T6 Upper & Lower Receivers

    Now, billet has the added advantage of looking crisper/cleaner and you can do some funky cosmetic stuff that you can't do with a forging because you are limited to the die on hand.

    Both billet and forged lowers have the same temper strength (T6) and just about all of the other measurements are within tolerances to call them equal.

    JABECmfg likes this.
  3. JABECmfg

    JABECmfg multi-useless Site Supporter

    Thank you @DarkLight - I had found the same link, and it is insightful. I work in manufacturing, and although I don't have much experience with aluminum, 7075 has proven to be the best bet for the applications we've used it for.

    For the purposes of the poll, let's say that we're talking ONLY about the merits of solid billet machined vs finish machined on the same equipment from forging, everything else (including grade of aluminum) held constant. What I'm really after is public opinion - I want to know what people prefer and why. (So if solid vs forged doesn't matter, vote accordingly.) And don't worry, I'm not looking to buy anything, so no one will be influencing a purchase by giving their opinions.
  4. Quigley_Sharps

    Quigley_Sharps The Badministrator Administrator Founding Member

    Great info thanks!

    I looked around at failures of lowers and I found this Oly failure. :


    Seems the guy used the motar technique to get a stuck case out, and broke it after a couple of drops.
    I'm not sure how any others would hold up to it either.
  5. DarkLight

    DarkLight I self identify as a Blackhawk Attack Helicopter! Site Supporter

    Ah...but are you looking to start MAKING something? Hmmmm...
  6. DarkLight

    DarkLight I self identify as a Blackhawk Attack Helicopter! Site Supporter

    Slightly off topic but was that receiver cast or forged. Cast is a whole different argument.
  7. BTPost

    BTPost Old Fart Snow Monkey Moderator

    A couple of NOTES, here on the Billet/forging Issue..... If you are talking the same material, spec'ed to the same Standard, then the difference would be only in the likelihood of Flaw in the Billet, against a Flaw in the Forging. Back in my Youth, (5 decades ago) I worked in a Machine Shop, as a Packaging Kid. They made both Finished Forgings, and Billet Parts.... The only difference was in the quality of the Metal going in. .......
  8. JABECmfg

    JABECmfg multi-useless Site Supporter

    You say that like it's a bad thing!

    No, not yet anyways... But, I've speculated off and on over the past couple years, whether it would be a worthwhile endeavor, and lately I've been thinking about it again. If I decide to commit to it, I want to know that it will be worthwhile. Getting the appropriate license is just the beginning - (rest assured, I won't be breaking any laws - those laws are nothing to sneeze at!) - but there are a lot of other factors to consider. I wouldn't do something like this blindly; rather, I want to know everything I can, so I can approach it with the appropriate knowledge. One of those things I want to know more about, is what do people think of one thing vs the other? In this case, billet vs forged.

    Think of it as market research, but without the spam emails and telemarketers trying to sell you something.
    DarkLight and kellory like this.
  9. Quigley_Sharps

    Quigley_Sharps The Badministrator Administrator Founding Member

    Its an Olympic Arms and as far as i know they only have forged receivers.
  10. VisuTrac

    VisuTrac Ваша мать носит военные ботинки Site Supporter+++

    yah mean like this?

    Airtime, Brokor and JABECmfg like this.
  11. JABECmfg

    JABECmfg multi-useless Site Supporter

    Something like that, yeah! Maybe instead of "safe, semi, SHTF", something like "live, dead, undead"...
  12. DarkLight

    DarkLight I self identify as a Blackhawk Attack Helicopter! Site Supporter

    Actually, when they first started they were cast for a time and the cast lowers had a TON of problems. The QC on them was almost non-existent. I can't remember exactly when they switched over but they did eventually switch to forged but people had a bad taste in their mouths for a LONG time. I know some folks that still won't consider Olympic which is, frankly, stupid and small-minded. Things change, people change, companies change. They've been in business this long, they've obviously fixed the original issues.
  13. ghrit

    ghrit Ambulatory anachronism Administrator Founding Member

    Is there any way you know of to determine if cast or forged from the s/n? I have an oly and no idea which it is. There are no casting fins or obvious machining marks.
  14. JABECmfg

    JABECmfg multi-useless Site Supporter

    @ghrit - I found an answer from Oly's website but I'm having a hard time posting the link...
  15. JABECmfg

    JABECmfg multi-useless Site Supporter

    Just tried again, to post the link only, this time with no text - I get a message that says I don't have permission to access...
  16. ghrit

    ghrit Ambulatory anachronism Administrator Founding Member

    Found it, thanx for the pointer. Cast.
  17. JABECmfg

    JABECmfg multi-useless Site Supporter

    No problem, glad I could help. Besides, it's not every day that I have something useful to contribute around here, so I enjoy being able to when I can. [winkthumb]
  18. Quigley_Sharps

    Quigley_Sharps The Badministrator Administrator Founding Member

    Is my receiver cast or forged?

    Q: Is my receiver cast or forged?
    A: This is another common question. Please not that Olympic Arms no longer uses cast receivers on any of our AR-15 models. Please use the information provided below to determine if your receiver is cast or forged.

    Is my receiver cast or forged?

    There are many differences that can easily be seen between the 2 types of receivers. Lest start with the magazine well.
    On all AR15/M16 style lowers, the magazine wells are beveled, or "ramped" to allow for a more expedient and reliable magazine change. The forged lowers start out life as a solid piece of aluminum. The cast lowers are a hollow casting from step one.
    These 2 photos show a comparison between the machined mag well bevel of a forged lower, and the "cast-in" or more rounded bevel of the cast receiver.

    Arrows highlight edges.

    This is a forged lower. On the moth of the mag well you can see a "machined bevel". A clear line is evident where the tooling actually cut the bevel in the mag well.

    Notice beveled edges.

    On this cast receiver, you can see that the magazine well bevel is much more rounded, and does not have any tooling marks, as there is no cutting done to the casting to create the bevel, as on the forged lower to the left.
    Here we will show the differences in the area surrounding the magazine release button, often referred to as the "fence". This fence was not on the original M16 lower receiver, but was added in later versions to help prevent the accidental release of the magazine, a potentially deadly situation in combat.

    Notice the wider fence.

    On this, the forged receiver, you can see 2 main differences. Above, the red arrows show the width of the mag well fence vertically. Below, you will see how the vertical fence line slowly tapers making a sort of point.

    No fence and no taper.

    Here on the cast receiver, the vertical fence is no tic ably thinner (more narrow), and the vertical fence line simply ends at the corner creating NO pointed taper.
    In this comparison we are looking at the magazine well fence; the ridge around the magazine well. This ridge is important structurally, in that it provides the thinner walls of the magazine well with some added rigidity, and leaves more material for the machining of the mag well bevel.

    Notice the smooth fence taper.

    Here the forged receiver shows a mag well fence that smoothly tapers into the mag well body.

    Mag well fence is a rounded lip.

    On the cast receiver, the mag well fence looks basically like a half-moon ridge that was stuck on the mouth of the mag well. It does NOT have the smooth transition from ridge to mag well body.
    Now we get to the 2 main noticeable differences. This set of photos shows a comparison of the selector switch stops on the left side of the receivers.

    Selector stops present.

    Here it is clearly seen that the forged lower receiver has selector stops marked "safe" and "fire".

    Cast has no selector stops.

    Here, on the cast receiver, those stops are noticeably missing.
    Finally, the real kicker, the inside of the magazine well. The pictures show the difference between the cast and forged mag wells. If you are to turn the lowers upside down, and point them away from you, you'd be looking at what we'd call the "leading edge" of the inside of the magazine well. There is a big and noticeable difference between the cast and forged receivers here.

    Mag well has a groove on the front.

    On the forged receiver there is a small crescent shaped groove that is machined into the from inside of the magazine well.

    Cast has no groove on the mag well.

    In the cast receiver, there is not groove. This difference is true of all of our cast and forged receivers.

    In closing here is some serial number information on cast receivers. We have made cast receivers on separate occasions, and these receivers have had distinctive serial number prefixes. When we first produced cast receivers in the 1993-1994 era, those cast receivers had a serial number prefix of "CA", which obviously stood for "cast". Our current production cast receivers have a serial number prefix of "SGW" which stands for our old trade name of "Schuetzen Gun Works".
    What this means is that all cast receivers have either one of those prefixes, BUT all CA and SGW serial numbers may not be cast receivers. I know, I know, this really puts some mud in the soup, but let me explain.
    Therefore, you could have an SGW or CA serial number and still have a forged receiver. That is why we have this page in our web site!
    JABECmfg likes this.
  19. JABECmfg

    JABECmfg multi-useless Site Supporter

    Thanks Quigley, that's the one!
  20. mysterymet

    mysterymet Monkey+++

    Forged assuming all quality control inspections being equal.
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