advise on ar 15

I was given a upper & lower (Anderson ) But Need a bcg for the 223 upper .new to the game ,what to know? Good or bad

Midway and Primary arms both have a lot of good choices. I do like the idea of the boron coated stuff for less lubrication on the bolt but I haven’t heard of any issues with any of the name brands.

Do you need it now, or can you wait for a sale?

Many people are currently buying Expo Arms brand, made by Microbest for Primary Arms.

Dang if I know the difference in BCG’s sometimes. I build my own and am somewhat AR “poor”. I prefer nitride finish and HPI and MPI bolts as it is easier to clean. But in the accuracy department there are too many variables to say with confidence that a BCG with chrome or nitride finish is better than one with phosphate finish.

In other words more expensive doesn’t mean more accuracy.

Whatever bolt you choose, since the bolt doesn't come already factory installed in the upper, be safe and get the new bolt/upper headspace checked. With a bolt action gun, you can feel insufficient headspace when you operate the bolt, but in a semi-auto, you can't. With modern CNC manufacturing practices, it should be OK, but if you get the 1 in 100,000 that's not, you could have a slam fire. I've had 3 AR's built from parts, and my little voice said "check them." One had insufficient head space, which meant the bolt would not have closed and locked on the cartridge. I avoided a potential KABOOM.
See pic attached

I’ll be the Soviet judge / fun sponge for many of the AR fan boys but here’s may take on it, based on Varmint hunting, Service rifle match, and tactical rifle competition going all the way back to the days when the only AR-15 game in town was the Colt SP-1.

1) All AR-15s with the exception of Colt and FN made rifles are based on reverse engineered examples rather than on the original technical data package;

2) “Mil-spec” is only praised by people who were never in the military and who don’t understand what “mil-spec” really means;

3) despite the 1-7 inch rifling twist “mil spec” hoopla, 1-9” is still the ideal twist for the 62 gr SS109/M855 projectile, and 1-12” twist while out of fashion is still ideal for 50-55 gr bullets. The only place where faster 1-8” and 1-7” twist barrels are an advantage is with longer and heavier long range match bullets, and even then my preference is 1-8” twist in a match rifle.

4) chrome lined bores make sense if you live in a swamp and can’t be bothered to clean your bore now and then. Similarly, unless you are doing full auto mag dumps they offer no real wear advantage over a non chrome lined bore. In a precision rifle that chrome bore comes at the expense of accuracy, and an AR-15 is capable of sub MOA accuracy with a match barrel, even with iron sights.

5) Despite all the non Colt, non FN reverse engineered AR-15s out there, for the most part when it comes to reputable brands (mid tier like DPMS, Rock River, PSA, etc), “parts are parts”. If they are properly made to spec, they are interchangeable and spending big bucks on boutique parts rather than decent mid tier parts is just a waste money.

6) piston driven uppers have downsides that cancel out the potential upsides. If you really want a piston driven rifle, there are better options than the AR-15.

7) you can tart up an AR-15 all you want with tacticool carp but the net effect is always negative as the rifle or carbine gains weight and slows down. Over about 3 decades of shooting tactical rifle matches I consistently enjoyed beating tarted up AR-15s and M4geries with a basic M16A1, XM177E1, or standard pencil barrel 16” carbine configured AR-15, all with standard carry handle sights, no optic, no quad rail, and no muzzle device other than a military issue three prong or bird cage style flash suppressor.

8) put your money in a good barrel rather than spendy bolt carriers, etc.

- Ballistic Advantage makes superb barrels that deliver 1 MOA accuracy and are properly stress relieved so they won’t start walking the point of impact as they heat up.
- Criterion makes very good match barrels for reasonable money if you are interested in service match shooting. Pair it with a service match legal freefloated handguard.
- A well made 20” bull barrel in a free float tube is still the go to barrel set up for a AR-15 Varmint rifle. My original DPMS Panther with its 20” stainless steel bull barrel is still a solid 1/2 MOA rifle without heroic handloading efforts (I load my Varmint and precision ammo on a Dillon 550B with a Whidden floating tool head).

ameridaddy said:

Whatever bolt you choose, since the bolt doesn't come already factory installed in the upper, be safe and get the new bolt/upper headspace checked. With a bolt action gun, you can feel insufficient headspace when you operate the bolt, but in a semi-auto, you can't. With modern CNC manufacturing practices, it should be OK, but if you get the 1 in 100,000 that's not, you could have a slam fire. I've had 3 AR's built from parts, and my little voice said "check them." One had insufficient head space, which meant the bolt would not have closed and locked on the cartridge. I avoided a potential KABOOM.
See pic attached

Click to expand...

Agreed. I have a set of go/no go gauges in .223 for AR-15 builds and I recommend people use them.

However in numerous AR-15 builds over the last 30 years the only time I encountered a head space issue was with parts from a bottom tier, Inver Grove Heights Minnesota based company notorious for out of spec parts.

I didn't build a complete AR-15 until I was in my late 60's. I started with a stripped Anderson lower and built the lower with quality parts from Spike's Tactical. The buffer, tube and spring were also Spike's. I then built the upper with an Anderson stripped upper, Del-Ton upper parts, Odin Works stainless steel 1 in 8" .223 Wylde barrel, and Midwest Industries M-Lok rail. I used a nickel-boron milspec BCG from AIM Surplus and topped the upper off with a Vortex Spitfire 3X prism scope. I shot that rifle for about a year and then upgraded the trigger to a Giessele G2S two-stage trigger. It's sighted for 100 yards and the optic has a 5.56 reticle to adjust for various longer ranges. I have to admit; I did not buy a set of headspace gauges, but I think BB57's recommendation to acquire them makes good sense. Fortunately, my rifle came out great and shoots like a dream. I've built one other AR since then and it does just about as well. Good luck; it's a lot of fun, even when you're old like me.

Check out the Palmetto State Armory website and look for Toolcraft bolt carrier groups which they sometimes offer on sale for less than $100; they're excellent and I've been using them on all of my builds, in particular the NiB coated ones.

I'm not price sensitive in the least; I buy Toolcraft bolt carrier groups because they're excellent.

Link below:

Just a moment...

The School of the American Rifle (SOTAR) has many excellent videos on BCGs. My best take on the various coatings is that the ones designed to make cleaning the BCGs much easier (which they most certainly accomplish, BTW!) are not really designed to run without the necessary lubrication: although an AR-15 CAN be "run dry", it is not without some possible (very?) negative effects on both reliability and durability...

Just my 2¢'s worth!

Cheers!

P.S. A nitride BCG can cost way less than a C-note and last for many thousands of rounds: a $250 Super Deluxe Lightweight (so-called "NAME BRAND"?) one made of 110% pure Unobtainium may turn a SOTAR physical into an autopsy in a heartbeat!

Lots of good information and suggestions here. All that I will add is, the BCG is pretty much the heart and soul of the AR platform. So, you really don't want to go the cheap route when choosing one. Good luck with your project.

Tool Craft supposedly makes a lot of the OEM bolt carrier groups.

I have been pleased with a Sons of Liberty Gun Works BCG.
Sons of Liberty Gun Works 5.56 M16 / AR-15 Bolt Carrier Group - Phosphate
Personally I believe that the BCG is critical to a properly functioning rifle and not a place to save money. Also, don’t go with a lightweight BCG unless you know how to tune the recoil/gas system of an AR015.

+1 on checking headspace. 308 ARs are more challenging to assemble and get functioning, but I’ve had headspace issues on both builds. Never had headspace problems on an AR-15 but there’s always a first time.