Well, I can't say that I'm as knowledgable as most on this board, but consider the components. First: the trigger. Some have better triggers than others. I have a RRA and a Doublestar lower. RRA has a match trigger. DS does not and you can definitely tell the difference.

So that's one thing. I'll let the real experts go on from there. Also, you can go onto AR15.com and I'm sure there's 20-30 pages on lowers over there.

There was a post on here and over at ARFCOM about the difference in lowers. If you work with Milspecs, you know that it DOESN'T mean that they are perfect by any stretch. It simply defines a material/process/tolerance/strength for a part. That's it. Sometimes they give lots of leeway, but with firearms, they're pretty tight in general.

I'm no AR-15 expert by any stretch, but from my research and limited experience, I feel the bottom line is that most lowers you buy, whether $70 or $250, will work and usually be compatible with most uppers on AR-15s. If not, a reasonably handy person can hand-fit them to make them fit together and run. IMHO, the difference between a Double Star $70 lower and a Larue $250 lower is pretty negligible if they're both forged/milled lowers. Cast lowers are not going to have as fine of metal finishing, but they should still shoot. In the end, you are paying for a name and a reputation. If you don't care, you'll most likely end up with just as good a shooter. Also IMHO, I believe an AR's inherent value is mostly determined by the upper you put on it. There are factors like triggers and grips, etc, but the barrel, handguard, and properly tuned gas tube are what makes them shoot tight groups and feed well.

you may be seeing the billet lowers going for 250+/- these days. Personally I think they are a waste of money (im not an expert) but I think you would be perfectly fine with a mil spec rra, cmt, cmmg, etc. if you are paying more than 150 for a stripped lower you are paying too much imho.

[This message has been edited by rhtexfish (edited 1/21/2009 8:54p).]

quote:

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you may be seeing the billet lowers going for 250+/- these days. Personally I think they are a waste of money (im not an expert) but I think you would be perfectly fine with a mil spec rra, cmt, cmmg, etc. if you are paying more than 150 for a stripped lower you are paying too much imho.

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This. The expensive stripped lowers are machined from billet.

Simple answer is Marketing and Supply/Demand.

There are only a couple of places that can forge aluminum. Colt doesnt even make their own...but look at the prices of a lower with a Pony on it. The rest is really percieved value. RRA vs. DPMS vs. Stag vs. Double Star.

Each brand is finished to a greater or lesser degree by the brand that sells it. Take a look at the forge marks on the front of the mag well, inside the trigger guard and behind the pistol grip. Compare different brands. Each company has its own level of finish or clean up, from the manufacturing process. The more you do to it to "clean it up", the higher your costs per unit. Labor isnt cheap.

The other issue is finishes. CMMG is really the only maker that puts a custom finish on their lowers, some kind of teflon. They also do a great job of clean up. But they have never been the most expensive lower...that tells me its really all about marketing and percieved value.

Milled lowers are a different story, but there again, its all done on a CMC machine. Billet lowers are not worth it, unless you just want something different.

PP

[This message has been edited by Puryear Playboy (edited 1/22/2009 8:26a).]

PP,
What about billet uppers for long range guns?

someone correct me if i am wrong, but lowers have nothing to do with the accuracy or function of the weapon. all they do is house the trigger assembly and hold the magazine in place for the bolt to strip off a new round. the bolt doesnt touch or ride on any part of the lower, and the firing pin couldnt care less if the lower is billet or forged, it sees the same strike from the hammer regardless.


so it really comes down do how you are going to use the weapon. if you are building a pretty gem to look at: billet. if you are building a workhorse utility weapon: pick a roll mark, any roll mark.

Accuracy is coming from the fit of the bolt to the barrel (ie most match barrels come with bolts fitted for them), the chamber, and the actual barrel itself. People love to say that their RR has the tightest upper to lower fit of any other AR, but guess what, it doesn't mean squat when speaking of the accuracy of the rifle, all it is is something to brag about.

One advantage of billet uppers is that they can actually machine the rail and the upper receiver out of the same stock which means continuous rail and added strength to the rail and receiver (think Vltor VIS or LMT MRP).



Edit: Spelling
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[This message has been edited by junior200414 (edited 1/21/2009 11:30p).]

This has been one of the most informative AR threads yet. I'm getting ready to build (if I can wait out some of the price issues of late) and this type of info is much needed. Thanks!

Billet uppers do flex less, so yes, they are more accurate. Is it measureable accuracy? Hard to say.

If you look at slow motion video of a stamped AK reciever it flexes all over the place during firing, but most milled AK's dont shoot much, or at all, better than stamped ones. The rest of the system is still pretty sloppy in a milled AK...chamber, bore, ammo, bolt spacing. So there are a lot of factors that must be accounted for when you have all that stuff moving around in there...

Lowers do nothing for accuracy that I am aware of, buy the best barrel you can afford with a Wylde chamber.

This thread has been added to the first post of the AR thread.

I keep seeing people refer to these mistakenly, so I'm going to clarify this right now. No one makes cast lowers anymore. All of the forged lowers are pretty much equal, and the billet lowers are pointless unless you want a pretty rifle that costs more money but shoots the same as a forged rifle.

Cast - Molten metal poured into a mold, which then solidifies into the desired shape. No grain structure to the metal. Typically has a rougher surface, due to the mold media (usually sand). Weakest.

Forged - Solid piece of metal is beat into shape between two forging dies. Can have surface irregularities, due to bits of metal remaining in the forging die from the previous forged piece. Very refined grain structure. Strongest.

Billet - A block of metal which is machined into final shape. Benefit is an almost flawless surfce. Strength varies depending on parent metal, i.e cast billet or forged billet.