im looking at some bcg's for my build and some normal ones and then i see some with fancy coatings, is there a real difference? is it worth it?

Yes, there's a real difference. The question is do you want that difference.

 

For example, bolts.

 

There's MPI tested, and high pressure tested if you are staying in the realm of the basic mil-spec configuration and materials. Having both MPI and HPT per unit testing is the best bet there because you get some assurance of lifespan.

 

Then you have coatings on the bolt. There's chrome. It can flake. There's fail zero stuff, which IIRC is nickel boron. It' is less likely to flake and is pretty decent. Both will make it easier to clean, and that's about it.

 

Then you have material. Mil-spec is carpenter 158 steel. You have JP making it out of much fancier steel than that.

 

Then you have deviations form the original design liek the lmt bolt that has a different shape to the extractor to have tandem extractor springs as well as a difference in the claw and bolt face design.

 

 

 

Then there is the carrier.

 

coatings

 

You can get chrome.. problem is flaking, makes it easier to clean.

 

You can get the mil spec parkerizing .. less durable on the friction front, but works fine.

 

You can get various flavors of titanium nitride. Which is less likely to flake, easier to clean than park, but offers no corrosion resistance like the above do. Those will be black or gold in color.

 

Then you have the fail zero coating, which is pretty durable and easy to clean.

 

 

Then there is mass.

 

You have the mil-spec m-16 profile in mil-spec steel.

 

You have the young's national match, which is heavier.

 

You have the young's light, which is close to the same weight.

 

you have the mil-spec derived semi auto, which is a tad lighter.

 

you have the young's ultra light which is lighter still.

 

you have the JP light carrier, which is about the same, but you can't use a forward assist with it.

 

You ahve the old JP aluminum carrier which is seriously light, has no forward assist and isn't made any more.

 

You also have a titanium one out there that isn't made anymore. But was seriously light and had forward assist notches.

 

then you have the LMT enhanced bolt carrier which has the gas porting in it changed to incrasae dwell time without increasing mass.

 

Then you have things like the tubb weight system to add lots of mass to the carrier.

 

 

 

What does combining all the above do?

 

Well, if you go with a light BCG, you can decrease your gas supply via an adjustable gas block, and if you ALSO use a buffer weight of the right mass, you decrease the reciprocating mass without negatively affecting the ability to feed reliably. Which means less recoil and muzzle rise, and possibly faster cycle times. With a good comp, that all adds up to faster shot to shot performance if you can actually work the rifle that fast. Doing that takes a fair amount of practice. For a lighter buffer, you either use a carbine buffer (and a spacer in a rifle length stock), use something like the JP low mass buffer, or just modify a rifle buffer and swap some of the steel weights out with aluminum rod.

 

If you go heavy, you can increase the dwell time. Which spreads the recoil impulse out, which feels mellower. But you are more likely to drive the barrel down when that big mass goes into battery, especially with a lighter buffer like you get in a carbine stock.

 

Then you have stuff like the lauer enhanced carrier that increases dwell time without increasing mass.

 

 

 

I could go on, but really, do you have to wait for the rifle to go back into battery you can get back on target that fast? No? Then you probably don't need one.

 

Are you going for maximum accuracy at all costs? Then go heavy, and spring for an easy to clean coating, because the increased mass is going to make stuff sluggish if you don't keep it clean.

 

that's an over simplification because the other half of the recoil and reliability equation is the gas system. That gets even more complicated.

 

Myself, I go with a properly tested mil-spec bolt. Why? because at the moment the JP and Lauer are about 2.5x as much, and don't necessarily have 2.5x the lifespan before you start cracking a locking lug. For the carrier, I go with an m-16 carrier as the small amount of extra mass helps mellow out a mid-length system even more. I also go with the longest gas system that works reliably with the barrel length I want. So mid-length in a 16", and rifle length in anything 17" or more. I don't bother with adjustable gas blocks anymore because if you ant the thing reliable all year round with whatever ammo you have, and you aren't going with a real low-mass setup, you basically have to leave it wide open anyway. So why spend the money.

Took me a second. BCG = Bolt carrier group, and not birth control goggles.

 

 

Threw me off there. Now I kind of want to find mine haha.

 

Sorry to get off subject.

Thank you matt. that was quite helpful. =)

dam raz thats some really good info. thanks!

+1 raz-0

Raz won.

 

Good info.

Great writeup Raz-0! +1

 

OP: I wouldn't worry about the fancy coatings. For the most part I feel it's bling. For what they charge for many of those exotic coatings, you could nearly buy a whole new quality BCG. Not to underestimate bling here... if you want it, then go for it! Sometimes personalization and just plan old thinking that something is cool is well worth the $$$.

 

Look for quality m-16 profile milspec BCG's.

Anyone know where the RRA BCG falls? Mil-spec?

 

What's all this stuff about Staked BCGs too?

Ultra top tier BCG: Spike's NiB (~$230)

 

Top tier BCG: BCM ($140) or Colt ($180)... Both are equal... BCM is cheaper.

 

Then everything else kinda filter down after that. Spikes phosphate ones are good, PSA one are supposedly good (even though they don't reveal where they came from). A lot of them come from the same manufacturer, so all that's different is the price and name.

Anyone know where the RRA BCG falls? Mil-spec?

 

What's all this stuff about Staked BCGs too?

 

Proper staking is necessary. What they are talking about with regard to that is the staking of the gas key. The gas key is screwed on. Staking is deforming the metal around it and the screws to create mechanical interference that prevents them from unscrewing. What you see people worrying about is too little staking. IMO too much is equally as bad. An example of not enough that you commonly see looks like someone took a big chisel across the top of the carrier and screws and applied pressure from top to bottom on the carrier. This dents all the bits that need to be deformed, but usually doesn't create an overlap of deformed metal, and thus misses the point. You'd see this a LOT on 90s era bushmasters and RRA. Heck, you'd see it a lot in 90s era ARs of all manufacture. The other common "bad" staking job you woudl see is denting with two pointed hardened screws from the top (one one each of the carrier key screws). This was more likely to work, but was often done wrong.

 

IF you click to soom in, this pic of a stag BCG shows the often less than adequate chisel from the top type of staking. It CAN work, but often the ones that work are also using some form of thread locker for an assist.

 

http://www.rainierarms.com/?page=shop/detail&product_id=114

 

The CORRECT way is to use hardened screws in a fixture dimpling in the gas key form the sides until the screws deform slightly. If you are careful, you can achieve acceptable results using a cold chisel form the sides, but it is more abusive to the key, screws, and carrier. Spikes standard carrier, BCM's carrier, and daniel defense's carrier all are good examples of properly staked keys. the daniel defense web store has a particularly good picture.

 

http://www.bravocompanyusa.com/PhotoGallery.asp?ProductCode=BCM+Bolt+Carrier+Group+AUTO+MP

https://danieldefense.com/components-parts/upper-half/complete-bolt-carrier-group.html

 

As always, when you say not enough of something is bad, there's a whole group of people who think that means more is better, and they usually fall into the crowd who think a bigger hammer or pushing harder can fix anything. On top of that, you have some fixtures like the moacks staking tool that will let them push as hard as they want.

 

If you go to http://www.m-guns.com/tools.php# and click on pocket moacks, theres a good picture that shows a mediocre 90s era screws form the top staking job that was probably sufficient, as well as the result of using a moacks tool to do an aggressive but probably still acceptable staking job. I've seen results form their tools that has essentially traded the fear that the screws might back out for the fear that the cracks you just put in the metal might spread and make the screws' presence irrelevant.

 

As a note, ABSOLUTELY DO NOT, try to "fix" the staking job and any bolt carrier that is coated with chrome, NiB, or any other nitriding process. The only one that might forgive you and not start flaking badly are osme of the titanium nitrides. They'll crack where you distort them, but they are pretty good about not having the damage spread and the coating flake.

 

IMO some example of parked good to go items in terms of staking are the following

 

Spikes phosphated

BCM's BCG

daniel defense's standard BCG

LMT's standard BCG

Young's manufacturing standard carrier (their chrome ones look good too)

 

There are others, but those are the one's off the top of my head.

 

The palmetto premium BCG looks like it is staked properly as well.

Anyone know where the RRA BCG falls? Mil-spec?

 

What's all this stuff about Staked BCGs too?

 

Rock river arms carriers are semi-auto profile, and their staking job uses the right methodology, but tends to be on the wimpy side, so YMMV. As far as I can tell they add a thread locker to theirs which helps. I have one in one of my uppers and have several K of rounds through it without issue. As far as MPI or HPT on the BCG? Dunno, I doubt it.

sorry for the noob question some here say auto and semi, are they talkin fully automatic? or does this mean something else?

http://www.bravocompanyusa.com/SearchResults.asp?Search=bolt+carrier+group&Search.x=14&Search.y=9

Yes - Auto means fully auto vs semiauto. Semi is semi-auto

anyone have the link for bcm semi bcg? i cant find it?

in for later!

called a bunch of times no one picks up! do they do price compare? or are there any coupons?

 

i saw this, price seems good.

http://www.midwayusa.com/Product/446331/dpms-bolt-carrier-assembly-commercial-ar-15-223-remington-tin-titanium-nitride-coated

called a bunch of times no one picks up! do they do price compare? or are there any coupons?

 

BCM deals via online sales and communication. They are a smaller custom outfit and not a larger organization. It's best if you simply emailed them your questions. They also don't use coupons or price comparisons.

 

FYI, BCM BCGs are in such high demand that they sell out a thousand or so within 24 hours.

sorry for the noob question some here say auto and semi, are they talkin fully automatic? or does this mean something else?

http://www.bravocompanyusa.com/SearchResults.asp?Search=bolt+carrier+group&Search.x=14&Search.y=9

 

Sort of. An m-16 proifile carrier does not have any ramifications in terms of being accused of trying to build a machine gun. Putting one in a semi-auto is perfectly fine. At one point it was a gray area, but that was hashed out with plenty of BATFE letters to prove it many years ago. However if you have an actual full-auto AR, you need one or it won't work right. It'll work in both and is a bit heavier.

 

A semi-auto BCG won't work right in a full auto gun, and is a bit lighter.

 

The difference is at the rear for the carrier on the bottom. If you look at the m-16 carrier, you will see the thinned area on the bottom ends at the same spot it does on the top. With the semi-auto version, it ends farther back on the bottom than on the top.

called a bunch of times no one picks up! do they do price compare? or are there any coupons?

 

i saw this, price seems good.

http://www.midwayusa.com/Product/446331/dpms-bolt-carrier-assembly-commercial-ar-15-223-remington-tin-titanium-nitride-coated

 

Dude, it's $139 for a MPI and HPT tested mil-spec BCG. Click the button and buy it or don't, I dare you to find something to compare it to that is actually similar and differs by more than $10. It's pretty much my go-to solution to the question of which BCG. It's affordable, it works, and it lasts pretty well.

 

You wnat a price atch on a great deal, but think $185 for a pimp gold BCG is a good deal. Myself, I don't know that I'd nitride the bolt. Depending on the process, it can be high temp or low temp. The operation of the bolt WILL wear through it. For example I have a low temp TiCN coating on my 2011. It's VERY hard stuff. But where the hammer rubs against the slide stop wore to bare metal in about 7,000 rounds because the hammer is softer metal than the slide stop underneath. I don't want a failing coating on my bolt (yes, park rubs off, but it rubs off to a powdery like substance that is similar to carbon fouling that the gun is designed to deal with. Not little very hard flakes). High temp nitriding processes will change the temper of the metal. That's not necessarily good for prolonging the duty cycle of the locking lugs, which are usually the first part to fail.

 

As for chroming a bolt, then you have to concern yourself with hydrogen embrittlement with regards to the locking lugs.

 

I said I was trying to keep it simple previously.

 

If you waqnt a fancy coating on your carrier. I suggest getting a carrier separate and either putting in a mil-spec bolt, or if you want fancy the JP or LWT bolts that are "better" via engineering and metallurgy rather than a coating. IMO bolts should not be plated or nitrided.

so i can use that bcm bcg that i linked to above? when i read it saying auto i thought it would be illegal for me to use, thats why i started looking else where... hey raz i appreciate your knowledge and patience, im still kind of new when it comes to an ar, but im learning everyday....

Yes, its perfectly legal.

ok thanks will be ordering...

ok thanks will be ordering...

 

The BCM? Excellent choice. Great quality BCG...

i didn't order yet, too busy today. I hate to ask this question but how does spikes tactical stack up to bcm? I have read that bcm has the track record, it's excellent and spikes is a newer co. and equal to bcm but spikes has a slighter better finish? ps I'm picking up a an upper assembly and bcg...

i didn't order yet, too busy today. I hate to ask this question but how does spikes tactical stack up to bcm? I have read that bcm has the track record, it's excellent and spikes is a newer co. and equal to bcm but spikes has a slighter better finish? ps I'm picking up a an upper assembly and bcg...

 

As far as I can tell, there are a ton of BCGs with all the same specs out there for about the same price they even have their logos laser engraved in the same spot. I suspect they all come from the same supplier, especially since several of them got in a pissing match over price and claimed testing. I think the reality is the spikes, BCM, and palmetto state armory BCGs are all the same part with different logos, and possibly slightly different sampling rates for the HPT/MPI testing.

Take a look at Denny's Thunderbolt. I own one and am very pleased with it. I bought it after researching quite a bit, and I got tired of waiting for BCM BCG's to get back in stock. My link

I picked up a Daniel Defense BCG earlier this year, simpoly because the BCM BCGs were always out of stock and I wanted to finish the rifle. No problems yet.

i ended up picking a matching spikes tactical bcg and upper from a place called bob's outfitters and used a code AR15 for some discount...price was right, and everything matches!

Take a look at Denny's Thunderbolt. I own one and am very pleased with it. I bought it after researching quite a bit, and I got tired of waiting for BCM BCG's to get back in stock. My link

 

 

Look like they should be ok. Don't like the sales pitch though. Better than mil-spec? They look like mil-spec BCGs that someone didn't pay to have MPT per the mil spec, nor have they been HPT unless they omitted that from the sales patter.