Home Forums Hunting & Shooting AR and Tactical Rifles Importance of Bolt Carrier Group quality

Any advantage to buying an expensive one?

BCG takes all the stress and does all the work.

I've had good luck with the PSA Mil Spec Premiums with the MPI tested 158 carpenter bolts.

Some bolt carriers are not chrome lined where the bolt fits in. You have to read the specs closely to make sure you get one that is. Quality bolts are hard to come by but they are out there.
Here is one that does not specifically say it is MIlspec and chrome lined nor MPI tested.
https://www.brownells.com/rifle-par...roup-nitride-mp-prod105377.aspx?psize=96

Here is one that is supposedly Milspec, chrome lined and MPI tested.
https://www.brownells.com/rifle-par...lt-carrier-group-prod78714.aspx?psize=96

Personally, I will spend a little more and get the Milspec and MPI tested. It's just that little extra that I think is worth the cost. You have to ask yourself, is this a plinker that would get shot one or two times a year and in not a self defense rifle or is this a battle rifle that you are going to shoot 3 gun with ? I don't do anything serious enough to warrant a Colt, BCM or Daniel Defense. But, you may.

kwg

I've seen more problems with cheap BBC's than most any other part. Good bolt carriers and bolts don't have to be expensive. Don't fall for the National Match carriers or special coatings unless you understand the coatings and want them. A regular parkerized and chromed bolt carrier will last forever. Bolts, I like them to be MPI'd after they have been HP tested and shot peened doesn't hurt.

I would believe that.

I never built one (actually I bought a parts kit in the early 90's and had a guy put it together) but that seems like an important part not to skimp on.

Spending the little extra for a known quality "milspec" BCG is worth it in the long run. You can get them pretty darn cheap now days so its not like you are paying much extra if any at all. However, I wouldn't spend significantly more on some of these "boutique" BCG's with whatever new slick coating is the craze this week. A standard phosphate M16 BCG will do fine.

Here's an example of a BCG NOT to buy.

https://www.midwayusa.com/product/3...-spec-ar-15-223-remington-556x45mm-matte

Notice how it's "Machined to mil-spec", but not really a Mil Spec item. Take a look at the negative reviews, and how many are due to total failures.

I have an AR stoner BCG in a cheap build for my 10 year old. As noted in the reviews, the machining is very rough, and I've experienced light strikes with it. It's fine for for now as a range plinker, but, at some point, it will get replaced with something better.

My Grandson is building it. He is a freshman in college. He does a lot of shooting and has a couple rifles that I built for him several years ago. He will be here a couple days during the Christmas break to load about 500 rounds. All the good brass that I have left. I'm good on 77 grain bullets. Bought a thousand during a fund raiser for the Texas State Junior shooters. I have about 15,000 primers, and I think he will need to buy powder.
This is the BCG that he thinks will be good.
http://palmettostatearmory.com/review/product/list/id/28961/

I have one. My wife's rifle was spitting and sputtering, just wouldn't run. Swapped out the cheap BCG for one of those and it hasn't had an issue since.

Thanks, I believe he will shoot a lot initially and slow down after he has to reload one at a time.

One thing I don't see discussed much is rifle extractors vs carbine extractors or springs to be more accurate. Carbine extractors take a different spring and sometimes an O-ring is added for extra bite but I've seen and heard of cases where even on a mid length gas system, it was too much. If he's running a rifle gas system, I'd stay away from extra coil springs and O-rings, there should be a blue insert on rifle springs and black on carbine.

One failure that was pretty comical to me, a guy bought a bolt carrier and other stuff off ebay pretty cheap and he was thrilled at how cheap his "build" was. He got it all together and it was a single shot. He tried many different things including an adjustable gas block before having me look at it. The gas key wasn't drilled through so no gas was unlocking the bolt. He then really started to question his "cheap" parts after that...

The only problem with a budget bolt I have had was improperly staked gas key screws. The gun began running poorly and after investigating the screws were loose. It appeared to be staked but no contact to the screws was there. It was a quick fix with a hammer and chisel (no bailing wire or duct tape was used).

To be an answer there must be a question.

So ----- as a former Marine, a former instructor for the DOD, instructor in both government and private sectors in various places, in and out of the USA I would throw out the question "What is wrong with the GI spec bolt carriers in standard ARs and M-16s"?

In all my years of gunsmithing and shooting, and in all the shooting I have ever seen done with M-16s for over 40 years I have seen some breakages, but never one with a bolt carrier. Gas keys yes. Carriers....NO!

So spending more on the carrier is supposed to remedy what problem? What is the question to which an expensive carrier is an answer?

We are going to have to talk about your "Bubba's Armory" skills. Ya gotta use the right materials......(grin)

Question was about the Carrier group, not just the carrier.

And to answer your question, there is nothing wrong with a GI spec bolt carrier group. The problems arise from commercial products of lesser quality.

It depends a lot on what you consider expensive. There's certainly a difference in a $175 and $100 BCG. The difference is much smaller between a $175 and $275 BCG.

What all parts have you seen break? I'm curious about trends in manufacturers and the timelines when they occurred. Thanks.

The failures I have seen most are gas key screws loosing and in a few cases, breaking. If the key gets loose for any reason the gun will short cycle and fail to function. Easy fix, but some men don't know what to look for.

Next would be oblong cam pin holes in bolts that have been used in full auto a LOT, which heats them and lets them cool over and over. I have never seen one fail personally, but I had a friend in the armory that had 6 of them in a box that had cracked through the cam pin holes. These were all from un-maintained m16s that should have had the bolts and barrels replaced long before this kind of thing happens, but in some countries such maintenance is just never done. I have seen the bores on many of those rifles and the rifling is shot out in front of the throats so you can make a guess how many rounds they had fired.

I have seen 4 broken extractors. All broken at the hooks.
One broken ejector. This one broke in half right where one shoulder of the pin cut-out is.
One broken firing pin tip.

I have a friend that has an Colt AR (Civilian gun) that had one lug break off, but he kept shooting it for a few years. It didn't seem to do any harm at all. I wanted to replace it and he said he's let me sometime, but for about 2 years he just kept using it as it was.
He finally got a new bolt and put it in.

I always buy a colt or dd bolt carrier group, the gas key screws are always staked, the extractor springs are set up correctly and the traditional metal is used with the inside chrome lined, I would also buy a BCM as well I think, I have a different philosophy i guess because I am not interested in the cheapest, I am interested in the gun working flawlessly.