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View Full Version : Which bolt carrier for an AR?


tools2teach
04-16-2009, 7:29 AM
I need to get a new bolt carrier. My question is are all bolt carriers the same in reliability and function? RRA, DPMS, LMT??? Should I spend the extra cash to get the rolex of bolt carriers?

jbooker9
04-16-2009, 7:53 AM
M16 bolt carriers are hevier, stronger, and more expensive. I would say get a RRA if you can find one. Shot well over a 1000 rounds with mine and not one problem. If you want the best go with young manufacturing they're $240 for the chrome But worth it if you plan to shoot alot

Vtec44
04-16-2009, 9:09 AM
I have RRA, Stag, Fulton and all work fine.

technique
04-16-2009, 9:13 AM
If at all possible (assuming you are not ordering one) hand pick one. Make sure it is staked correctly.

I prefer a FA carrier. I never go with the fancy BCG, they are a waist of money.

FA BCG...average $135-$150

If you want it Chromed...$40

Agro
04-16-2009, 9:15 AM
Don't be confused. There isn't a huge difference between BCG's from the top manufacturers. Some don't care much for the chrome, some do. If you're on a limited budget, the BCG is not where you want to invest your limited funds. Get any BCG, properly stake it and lube it up well. Invest the rest of your limited funds elsewhere like optics or what not.

If you have unlimited funds, then why not get a Young Mfg N/M chrome BCG (m-16 F/A) or the new FailZero shindig.

Barney Gumble
04-16-2009, 9:20 AM
I need to get a new bolt carrier. My question is are all bolt carriers the same in reliability and function? RRA, DPMS, LMT??? Should I spend the extra cash to get the rolex of bolt carriers?

They will pretty much all work fine for everyday use at the range. If you are taking a carbine class or in LE/MIL then it's a little different but really it's only the bolt that takes a beating. I've never heard of a carrier breaking but bolts will break with enough use. For hard-use situations I'd go with an LMT, BCM or Colt bolt.

M16 bolt carriers are hevier, stronger, and more expensive. I would say get a RRA if you can find one. Shot well over a 1000 rounds with mine and not one problem. If you want the best go with young manufacturing they're $240 for the chrome But worth it if you plan to shoot alot
Lots of myths there...M16 carriers are not more expensive...1000 rounds is nothing, shoot 30,000 rounds and then tell me...chromed bolts should produce less wear but the average shooter doesn't shoot enough to make it worthwhile.

Clark_Kent_X
04-16-2009, 9:45 AM
FA LMT enhanced bolt and carrier....$300 at CMMG Inc. (http://cmmginc.secure-mall.com/shop/?cart=1626407&cat=28&)

mike452
04-16-2009, 12:18 PM
I need to get a new bolt carrier. My question is are all bolt carriers the same in reliability and function? RRA, DPMS, LMT??? Should I spend the extra cash to get the rolex of bolt carriers?

Just get the standard! They all work the same. Only chrome is the Rolex of bolt carriers. All others are like tampons.. canít show them off to anyone.

technique
04-16-2009, 12:30 PM
FA BCG...average $135-$150

If you want it Chromed...$40

http://i285.photobucket.com/albums/ll42/technique408/chromebolt001.jpg
http://i285.photobucket.com/albums/ll42/technique408/chromebolt003.jpg
http://i285.photobucket.com/albums/ll42/technique408/chromebolt002.jpg



*has yet to be re-staked*

buffybuster
04-16-2009, 12:37 PM
I would not get a chromed bolt carrier or chromed bolt. It gives you no benefit and potentially some risks.

As long as the bolt and bolt carrier are made from the proper materials (I think 8620 carbon steel), hardened properly and assembled correct (gaskey staked correctly, etc) it will function and last a very long time, as long as it is maintained correctly.

It doesn't make much sense (other than making $$$ and cleaning) to hard chrome a component that has already been nitrided. If anything I would be concerned about hydrogen embrittlement with the small surfaces of the lugs.

My .02

Vtec44
04-16-2009, 12:48 PM
I would not get a chromed bolt carrier or chromed bolt. It gives you no benefit and potentially some risks.


What are the risks? I just want it because of the ease of cleaning, especially on the end of the bolt.

Josh3239
04-16-2009, 12:53 PM
Some people believe chromed is more brittle, it has a better chance of breaking. I have been running a chrome carrier and love them, I just picked up 2 LMT chrome bolts and 1 SEI chrome bolt. Since the carrier doesn't get too dirty I don't notice a difference in clean up but they do seem to hold lubriacation better/are more "slick". Many people have said the bolt are much easier to clean, I can't speak on that yet.

oddball
04-16-2009, 1:09 PM
The difference between bolt carrier groups from someplace like Bravo Co. and LMT, vs. RRA or Bushmaster is the specs. The former are mil-spec, (properly staked, gas key hardening etc.), magnetic particle inspected, and shot peened.

Most folks shooting at the range will most likely not be abusive to their rifles as the guys in carbine classes (shooting over a thousand rounds in a weekend), and not benefit from a mil-spec bolt carrier group. But if you can get one for the same price as the others (BCM Bolt carrier group Auto is $130), why not?

buffybuster
04-16-2009, 1:16 PM
What are the risks? I just want it because of the ease of cleaning, especially on the end of the bolt.

I've seen a couple of instances where the chrome started to flake off the locking lugs on the bolts. They will then begin to gall the lug seats. However, my primary concern would be hydrogen embrittlement of these small components, thereby weakening them.

In my mind, the benefits of hard chroming these components are not enough to counter the potential concerns and added cost.

Aftermath686
04-16-2009, 6:16 PM
I run a Young's and shelled out the extra coin because of the word of easy cleanup... To be honest I was a little disappointed due to the fact that I was under the impression that all carbon would just wipe right off with some oil and a rag. That is the case for most areas but the bolt tail does need scraping after a significant number of rounds. Now I do think the hard chrome has less carbon buildup than a standard BCG... But there is still a significant amount of buildup if your shooting a lot. I was probably naive in my initial beliefs but overall I am satisfied, it has performed well and, upon visual inspection, one can tell it is a quality piece. And I love the look of this BCG

Not to long ago I attended a Magpul Carbine 2 class and I do think it made cleaning a little easier than it should have been, had I been running a standard BCG.

http://farm4.static.flickr.com/3638/3405767491_e14f91306f_o.jpg
Near: Youngs BCG, Far LWRC both after one day of Carbine 2 class. Obvious advantages of Piston system seen here. Nether have been cleaned.
http://farm4.static.flickr.com/3449/3405728471_9a869d736c_o.jpg
http://farm4.static.flickr.com/3654/3405728583_3797f00736_o.jpg
All Of the carbon seen on the BCG was wiped right off with no problem... The only place scraping was needed was on the bolt tail.
http://farm4.static.flickr.com/3465/3405728611_9cf29d84d1.jpg?v=0
After Cleaning:
http://farm4.static.flickr.com/3438/3405728735_417dc79dff_o.jpg

ArcLight
04-16-2009, 6:34 PM
I heard Fail Zero (http://www.failzero.com/armory/ar-15.html)makes darn good products. Oh and they dont need to be lubricated.

Ishoot
04-16-2009, 8:35 PM
I heard Fail Zero (http://www.failzero.com/armory/ar-15.html)makes darn good products. Oh and they dont need to be lubricated.

Anyone with first hand experience with this? I'm in the market for one to have extra.

tools2teach
04-16-2009, 8:38 PM
I just pulled the trigger on a fail zero bc. Mark from
Rainers swears a it. Have a 30 day return policy and a lifetime guarentee. I figure I would give it a chance

Aftermath686
04-17-2009, 1:52 PM
Yeah I too am curious about the Fail Zero... Haven't heard much first hand experience.

Vtec44
04-17-2009, 1:55 PM
I'm curious about Fail Zero also, so please post a report after few rounds :D

supersonic
04-17-2009, 2:40 PM
I am firmly against "hard-chromed" or "chromed" (is there really such a thing as "soft-chromed?":rolleyes:) BCG's after speaking with a few industry experts like Mike Sweeney & Ned Christensen. Hell, even good 'ol Garson @ CMMG told me the same thing and it made perfect sense:why put a BC that is THAT HARD into an aluminum upper receiver? Yeah, it may work just fine for 300, 400, 600 rds......BUT: you are going to see some MAJOR wear in your upper soon after, plus the life of it is going to be cut in half. Think about it. It would be similar to GLOCK putting aluminum rails in their polymer slides. Food for thought.

hawk81
04-17-2009, 5:11 PM
I would get an mpi (mag particle inspected bolt). All of mine are, but I did them myself since I am a certified level 2 MPI inspector. I have checked 12 of mine and none have any linear indications or defects.

supersonic
04-17-2009, 8:16 PM
I would get an mpi (mag particle inspected bolt). All of mine are, but I did them myself since I am a certified level 2 MPI inspector. I have checked 12 of mine and none have any linear indications or defects.

Where are you located? How much would it cost me per bolt if I wanted you to MPI them? Also, What is a "level II" inspector? Thanks,
-Scott

The Bacon Eater
04-18-2009, 1:19 PM
If anyone is interested i contacted fail zero and they are offering the f/a carrier for the same price. Give them a call or email them to reserve yours. They are shipping on Friday.

Plisk
04-18-2009, 1:26 PM
I heard Fail Zero (http://www.failzero.com/armory/ar-15.html)makes darn good products. Oh and they dont need to be lubricated.

Yeah I too am curious about the Fail Zero... Haven't heard much first hand experience.

I'm curious about Fail Zero also, so please post a report after few rounds :D

My FAILZero is in the mail, within 2 weeks my AR15 shouuld be GTG, I will be posting an aftermath report about it.

bohoki
04-18-2009, 9:30 PM
I am firmly against "hard-chromed" or "chromed" (is there really such a thing as "soft-chromed?":rolleyes:) BCG's after speaking with a few industry experts like Mike Sweeney & Ned Christensen. Hell, even good 'ol Garson @ CMMG told me the same thing and it made perfect sense:why put a BC that is THAT HARD into an aluminum upper receiver? Yeah, it may work just fine for 300, 400, 600 rds......BUT: you are going to see some MAJOR wear in your upper soon after, plus the life of it is going to be cut in half. Think about it. It would be similar to GLOCK putting aluminum rails in their polymer slides. Food for thought.

baloney

glock polymer slides?

tools2teach
04-19-2009, 9:23 PM
I just received my fail zero bc in the mail today. Upon closer inspection it appears to be very well made. The feel is very smooth, almost silky like. The instructions say no lubrication is needed, just a brush to clean off the gunk. Haven't had the chance to take it out yet to the range. i will give you guys a report as soon as I do.

sb_pete
04-19-2009, 9:36 PM
It would be similar to GLOCK putting aluminum rails in their polymer slides.[/I] Food for thought.

+1 to above

AFAIK, Glock and all other makers of polymer frame pistols use steel slides with some form of coating (tenifer, etc.) which ride on steel rail points (one small partial rail on each side protruding from the frame in the case of Glock and HK, 2 longer rails in the removable subframe of the Steyr's, etc. etc.).

Your sig says you are a Glock certified armorer though, so I'll assume you know what you're talking about. Care to explain what you mean?

___

The hydrogen embrittlement strikes me as a valid concern, although I know nothing about this phenomenon. How does this occur? Whatcha guys talking 'bout?

As far as hardness, I can see what you're saying in that, for example, steel bolts in aluminum parts makes for not so durable bolt hole threads. That said, my understanding is that chrome is inherently smoother and thus slippery-er. Hence, it would tend to wear the aluminum upper receiver less than a BCG coated with a less slick treatment. As is, the bolt will always be a steel part riding in an aluminum frame. It would seem to my uneducated guestimation that chromed or nitrided BCG's would wear the inside of the receiver less than simple phosphate coating. Is this correct? If not, then why?

-Pete

TwitchALot
04-19-2009, 10:32 PM
But if you can get one for the same price as the others (BCM Bolt carrier group Auto is $130), why not?

I'll tell you why. Because I want a BCM BCG, and if you think they're all the same, go ahead and get your DPMS or RRA BCG and let me have a better of chance of getting what I want. :p

Vtec44
04-19-2009, 10:39 PM
AFAIK, Glock and all other makers of polymer frame pistols use steel slides with some form of coating (tenifer, etc.) which ride on steel rail points (one small partial rail on each side protruding from the frame

This is also the design in my XD9, hence the rail on the lower polymer frame doesn't have to be steel plated.

series8217
04-19-2009, 10:46 PM
How much heavier is the FA / M16 bolt carrier than the nerfed semi-auto AR-15 carrier?

series8217
04-20-2009, 10:52 PM
Anyone around San Gabriel / Monterey Park have an M16 carrier I could borrow for a couple hours to weigh it on my scale at work?

galabomber
04-21-2009, 8:59 PM
So how did the Fail Zero BCG go?

I'm interested to hear.

reidnez
04-22-2009, 3:12 PM
How much heavier is the FA / M16 bolt carrier than the nerfed semi-auto AR-15 carrier?

An ounce or two, I would not think more. The bottom-rear of the carrier is milled further back on the AR carrier since it doesn't need to trip an auto sear, that's about the only difference to my knowledge. This picture shows the bottom-front portion of the AR carrier (underneath the firing pin) milled out as well, but my AR carrier does not look like that.

Top: AR15 BCG
Middle: Colt SP-1 BCG
Bottom: M16 BCG

http://quarterbore.com/images/ar15_sp1_m16carriers_sm.jpg

reidnez
04-22-2009, 3:15 PM
So how did the Fail Zero BCG go?

I'm interested to hear.

Ditto! I am seriously considering one of these.

galabomber
04-22-2009, 3:24 PM
I found that guy (or at least one guy) with the Fail Zero BCG on another thread. He's DROSing today... So we won't be able to find out for at least another 10 days.

aplinker
04-22-2009, 9:09 PM
I would get an mpi (mag particle inspected bolt). All of mine are, but I did them myself since I am a certified level 2 MPI inspector. I have checked 12 of mine and none have any linear indications or defects.

Shot peened, HPT then MPI'd is what you want for the bolt.

M16 carriers are better for carbines (they typically want more mass), but unnecessary for others.

The Young NM carrier is silly. The LMT enhanced is ONLY for carbines, pricey and not really the best fix (just get a midlength upper).

JP has some carriers/bolts that I wouldn't hesitate using in specialized applications, or if they were just cheaper.

eaglemike
04-22-2009, 9:20 PM
Hydrogen embrittlement is a risk if the process isn't done properly. I'd think the manufacturers would have the process under control, but who knows these days. If carbon steel above a certain strenght level is chrome plated, it needs to be baked withing a certain length of time at a certain temperature to avoid this risk. I don't remember the spec's any more, and didn't keep copies of them back in the day. I could likely call some old contacts if it's important - but someone else will likely speak up soon. Above a certain strength level the inside corner radii also become more important. (well duh!)
all the best,
Mike

The Bacon Eater
05-06-2009, 5:13 PM
I finally got out to the range today. I shot 350 rds through my fail zero bcg with no lube and had zero problems. Not to say that a regular bolt could not do it since i have heard that a phosphate one can take about that with no lube. Took it home and cleaned it with a rag. Easy to clean. I wish ammo prices were cheaper, so i could run 1k through it.

I also got to break in my Young n/m m16 bcg today and it ran like a champ, but i had to use clp on that one. I put about 250rds through that one and had zero problems. Easy to clean and looks great.