AR-15 Bolt Carrier Assemblies?

Hi, folks.

I have inherited a pair of really, really nice, hand-assembled assembled AR-15 rifles, a carbine and a long rifle. The owner and his gunsmith friend chose the parts without price being a factor. These are not my first - I own an Olympic Arms carbine as well and have shot and maintained it for several years. For safety, the owner removed the bolt assemblies from the pair I inherited. We've looked for them and can't find them so we must assume they are gone. My questions are:

1. Must replacement AR-15 bolt assemblies be fitted or can I go down to the a local AR-15 specialista gun shop (we've got one), select replacements, mount 'em up, and go? My Oly Arms sheared the cam pin on one of my first range trips. I took the rifle back to the selling dealer for advice and warranty help. The dealer took one look, pulled the bolt goup out of another Oly on the wall, and handed it to me. It struck me that there appeared to be no need for fitment.

2. There are bolt assemblies and there are bolt assemblies. Some shops will attempt to sell you the best, or even insist. An online shop provides you with the opportunity to buy CRAP without advice. Is there a price or feature threshold that I can reach that is "good enough" or will be good for a nice rifle?

Bob

That's a good question Bob that I've never ever really thought about. I have switched BCG's on a few of my ARs without problem.

You can switch bolt groups without any issue. Stick to name brands, read up on them. Don't buy crap, I've never even heard of a cam pin shearing. Cheap is cheap.

A friend was telling about a new Ruger AR15 in 5,56mm. He at the range and as the shooter fired the Ruger, there wasn't any ejection? the empty was still inside
the rifle. He got the empty out and fired again, still no ejection. They took it apart, the new Ruger has a cam pin hole without taper. You can put the bolt inside the
carrier with the extractor on the left side or you can put it into the carrier the correct way - with extractor on the right side. Maybe the design was for both right
and left handed receivers ? You can not do this with a Colt

I like to use Faxon BCG's in my builds because I usually use Faxon barrels. If I am replacing a BCG or building a gun without a Faxon barrel, I like to use Aero Precision BCGs. Both companies build these BCGs in the USA and back them up. I have purchased cheap BCGs online and at gun shows and had some problems. I later learned that many of them are built in China. The BCG is the heart and soul of your AR so spending a little extra for a quality BCG is always a good idea. Hope that helps!

You can swap BCGs and bolts around and probably never have an issue. Tolerances are so tight these days, they will rarely stack badly to cause problems. I can't even remember which bolts originated with which rifles for most of my ARs, including the one that wins CMP National Match competitions.

I've been able to talk to the gunsmith who built the rifles. Actually, what I have is a rifle and a pistol AR. He said they could use anything from Milspec grade up but the pistol really should have a Nickel Boron BCG and the long rifle should probably have a nitride BCG for longevity. I'm going to keep looking for the originals but now I've got an idea what I need.

Bob