Ar-10 knowledge needed

similarity for parts is pretty much restricted to the lower, i.e. trigger, hammer, pins. detent pins and springs, fire control selector, buffer stop and spring, bolt catch plunger and spring. everything else is unique to the lower you buy. PSA stuff is DPMS pattern, and my experience with 2 PA10's is poor fit between the upper and lower. similarity in the upper seems to be DPMS pattern uppers all take DPMS style BCG.

i just finished a Falkor Defense build, very nice stuff but pricey, very pricey. i also just finished an Aero Precision M5E with a 16" barrel. i used Ballistic Advantage barrels in both of them, working on 2 additional Aero Defense M5E's as well. i really like the Aero melonite bcg, i put a FailZero Bcg in the Falkor. i used armalite buffers,extensions,and buffer springs in all 4 of them.

right now parts are hard to source, at least that's what i found out. the Falkor, Aero, and Mega all fit together tight, but they all seem to have their own unique parts list, the good thing is the unique parts are not something you'll be changing often.

that's all i know about them, cept put an adjustable gas block on em

crayj is right. I recommend getting both an upper and lower from the same company. The 2A Xanthos is the lightest by far but expensive. I really like my Tactical Machining receiver set, the price was good.

Most of the last 6 months anything related to AR10/AR308 have been sold out as people have found they can build a much lighter 308 rifle that the heavy 9-10 pound safe queens of companied before. I always laugh when some big company announces they have a 8 pound AR 308, or even their super light 16 inch models at 7.5 pounds. The AR308 is the "New Barbie for Men"

The most important items are the barrel and the receiver set. Get light weight ones and you can use everything else normal weight and still be under 7 pounds.

Musts for 308s are an adjustable gas block and the POF roller carrier pin.

Really the only tools you need is a barrel nut wrench, and depending on the hand guard it may be specific to the company. They don't make a upper receiver lapping tool yet. There are blocks on eBay that hold the upper both top and bottom, sideways in a vice. These work for both Ar15 and AR308s. Or easier is just take the upper and barrel plus nut to a gun smith and for less than the cost of tools they will do it usually under $35. I did it that way for my first couple of builds.

Using light weight aluminum take down pins or titanium ones as well as the gas block are ways to save weight with just a little more cost over other premium parts.

To expound on crayj

used armalite buffers, extensions, and buffer springs in all 4 of them.

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the shorter carbine DPMS pattern gas tube requires shorter and MUCH more expensive buffers. POF Company (DPMS pattern) and Armalite uses longer 7 position buffer tubes that allow regular AR15 buffers with a huge assortment of weights and quality, all half the price of an AR308 buffer.

NEVER build an AR308 without an adjustable gas block

I should mention I would NEVER build an AR308 without an adjustable gas block.

A standard weight AR 308 BCG and buffer/spring acts like a sledge hammer! The AR 15 in comparison is a ball peen hammer.

But by using a light weight BCG and buffer (with adjustable gas block) it acts much closer to an AR15. HUGE difference.

The accuracy with the 130 Mk319 ammo really improved with the lighter titanium carrier. Before the 3-5 shot groups were one inch or larger. With the lightest BCG the accuracy was closer to half an inch.

crayj said:

the PSA takedown pins i had were shaped like an AR15 takedown pin, a round head take down pin which Aero, Falkor and Mega use, would not extend all the way thru the PA10 when trying to assemble it. might as well use duct tape

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I'm not talking PSA AR15 pins, I'm talking standard AR308 pins. They lock up tight in a PSA 308 lower. Unless you're saying the PSA 308 pins wouldn't work in a different lower? Here's mine, that I've been running for quite a while.

Several PSA lower parts are proprietary so it's smart to do the research and use the correct parts. Other 308 and AR15 parts may work but they could also fail at the worse possible moment. You also need to research what lowers will actually work with PA10 uppers. Some will not. I made the mistakes right away when I built my first PA10 lower. Use a PA10 LPK and you'll never have problems. If not into possible, unexpected problems when you are building an AR10 platform rifle you must realize right away that most have proprietary parts that need to be used for a correct fit and function. If you are into jerry rigging stuff together hoping it will fit right go for it. What will generally happen is you'll end up spending more money down the road trying to fix it.

PA10: Bolt catch, mag catch/release, take down pins are all proprietary. Use other parts and you risk failure and poor fit. Their design also uses the same roll pin secured bolt catch an AR15 uses (bolt catch is not AR15 and stronger). If you buy a DPMS 308 LPK the bolt catch threaded attachment included will not work the pins are different, the bolt catch is different and the mag catch are different. Basically, you pretty much wasted your money.