Are all AR15 bolt carrier groups the same?

[41MB-04TJ]

I am piecing together a rifle and I have a standard "Mil Spec" parkerized bolt carrier group from something else that never got used, but this thing is ugly. There are prettier ones out there and it is giving me second thoughts. Is there anything about the fancy bolt carriers or bolts that are going to make any difference in accuracy from a good barrel? I want to use the BCG that I have, but some of these new things are pretty shiney, and are tempting me. I can understand the lubricity of certain coatings as well as the abrasion resistance but this rifle will be for shooting 10-20 rounds a range day, not an action shooting tool.

I would like the feature of some kind of chrome plating or nickel boron on the whole group for the ease of cleaning, but I can think of better ways to spend that money. Though when it is all said and done, $100-$150 isn't going to be a cupful in the pool of money spend building this thing, ugh.

So aside from peripheral benefits, will I see a performance increase on paper with a more expensive bolt carrier group?

Thank you.

 

[distinguished]

I have used both types of carrier and there is no difference in accuracy that I can detect. The so called national match carriers are just a marketing gimmick.

 

[jonbearman]

I have been running a frankenstein gun for years,here is what it consists of:
It has a armalite barrel that had the flashider removed and it tore all the threads off,now it is 19" and rethreaded with my own designed muzzle brake,it also has been cryoed after all the machining.Bolt carrier group out of who knows,hi-rider extruded upper reciever(70.00) cheapy.Lower is a bushmaster lower with a jewel trigger.It has an a-2 buttstock and an armalite buffer assy I think. It has a sherluk cheapy freefloat handguard(I made my own out of stainless hydraulic tubing with cooling holes) I took it off to lighten the gun.It has a set of millett windage adjustable rings and a 6.5x20x40 weaver 40/44(cheapy)(works well) All put together by me.It will shoot 69grain sierra matchkings into a .3 circle.What do you think of that.If you have a gi spec BCG,run it wet in the cam key and bolt gas ring area.The problem with alot of ar's when they wont feed right or jam mildly ,it is caused by lack of lubrication.I use GI LSA.It is a thick sloppy oil and works perfectly.Any questions pm me and I will give you my phone number.

 

[15Tango]

The so called national match carriers are just a marketing gimmick.

Plus 1 on that! The only possible thing design wise that I could be talked into buying if the price was right would be one of the non-tilting carriers.

Eagle Armory for the win - Rock River bolt carrier group $116 shipped http://www.eaglearmory.com/index.php?main_page=product_info&cPath=22_51&products_id=35

They also have the Rock River dual stage triggers for $94.99 shipped. Great site to buy from.

Wayne

 

[AaronSDMF82]

The so called national match carriers are just a marketing gimmick.

Absolutely. Better off Putting in a 5 dollar accu wedge.

Even after tens of thousands of rounds the last thing you will have problems with is the bolt carrier, point being even the super slick ones like LWRC or POF are really unnecessary and if your not shooting that much save your money.

 

[Viperdoc]

But there are differences in BCG's. The AR-15 BCG is a lot lighter weight than an M-16 BCG, which has a lot more metal. In combination with a carrier weight system (sold by Sinclair), you can add a substantial amount of weight and mass to your BCG. The result, according to claims, is to keep the gun in battery longer, and make it withstand more pressure. In my handbuilt AR, using a brass deflector, all of the brass end up no more than two feet in front and to the right. The bolt action is noticeably slower, and it seems like I can go at least a full grain heavier in loads than published without pressure signs like flattened primers, etc.

I tried one of those hydraulic buffers from Olympic arms, and the gun always short stroked unless the loads were really hot. I suspect it might work for NATO rounds, but for 223 it has too much resistance, even when turned down to the lowest resistance. Not worth the money for a standard 223.

However, there are differences more than cosmetic in BCG's.

 

[15Tango]

But there are differences in BCG's. The AR-15 BCG is a lot lighter weight than an M-16 BCG, which has a lot more metal. In combination with a carrier weight system (sold by Sinclair), you can add a substantial amount of weight and mass to your BCG. The result, according to claims, is to keep the gun in battery longer, and make it withstand more pressure. In my handbuilt AR, using a brass deflector, all of the brass end up no more than two feet in front and to the right. The bolt action is noticeably slower, and it seems like I can go at least a full grain heavier in loads than published without pressure signs like flattened primers, etc.

The original purpose in the difference in BCG weight from an AR15 to M16 wasn't for weight but to make it harder to convert an AR to full-auto. The rear portion that trips the auto sear is cut back farther on the AR15 carrier so it can't work with an auto sear. There are also carriers out there that have a cut away near the firing pin as to catch a hammer on the firing pin if a disconnector fails.

There's truth in adding weight will add dwell time to the cycling but if you have a heavier carrier with a heavy spring you'll find that oftentimes it won't lock to the rear and fail to cycle fully on light loads. An increase in carrier weight oftentimes requires a decrease in spring rate. X+Y still needs to be pretty close to Z or you'll have issues. Too fast of cycling trying to open the bolt too soon causing undue bolt, carrier and extension wear and throwing brass 15 yards or an action that's trying to not open soon enough.

Stick with standard carrier and you'll be fine for the type of stuff we're all doing. I had issues with loads that were stout not locking open with a Wolf extra power spring and standard carrier and rifle buffer in my 20" HBAR. In my Grendel carbine I was having the opposite issue with the carbine buffer and standard spring, had to go to the extra power to keep things tamed down in that.

Wayne

 

[MT204]

The so called national match carriers are just a marketing gimmick.

Absolutely. Better off Putting in a 5 dollar accu wedge.

Even after tens of thousands of rounds the last thing you will have problems with is the bolt carrier, point being even the super slick ones like LWRC or POF are really unnecessary and if your not shooting that much save your money.

Well I wouldn't go so far as to say it's the last thing you will have a problem with. The following picture is of an ar bolt carrier that the bottom "blew" out of it. Had less than 200 rounds through it. It was 204 ruger by the way.

 

[15Tango]

That is crazy! That must have been a pretty catastrophic event to break not only the carrier but the bolt as well. Cool picture. Know any more of the story?

Wayne

 

[distinguished]

There has to be more to this story! Inquiring minds want to know.

 

[AaronSDMF82]

The so called national match carriers are just a marketing gimmick.

Absolutely. Better off Putting in a 5 dollar accu wedge.

Even after tens of thousands of rounds the last thing you will have problems with is the bolt carrier, point being even the super slick ones like LWRC or POF are really unnecessary and if your not shooting that much save your money.

Well I wouldn't go so far as to say it's the last thing you will have a problem with. The following picture is of an ar bolt carrier that the bottom "blew" out of it. Had less than 200 rounds through it. It was 204 ruger by the way.

Ok...hope you were not injured badly, but that is a exception i wont ask if it was operator induced or faulty parts or ammo BUT a BCG just doesnt blow out after 200 rounds period.

Now I have very little experiance with the 204 and other "hotter" variants of the AR but I know for a fact proper care and usage and BCG will last a LONG time and even after hard wear and tear a M4/AR-15 platform are more prone to firing pins breaking, extractors wearing out, buffer assemblies, hammers, sears, gas keys and things of that nature.

 

[Viperdoc]

Agree with the previous posts, but not sure why a bcg should fracture. Again, the heavier weight m-16 bcg along with the carrier weight system with standard spring and buffer seem to increase the time in battery. Advantage? Seems to tolerate heavier loads and higher velocities without pressure signs that might be apparent with the lighter bcg. Never had a problem with functioning with bullets from 55-77gr and ladders starting with quite loads.

I did try the Olympic arms hydraulic buffer in combination, but every load except the very hottest would short stroke. It was simply too much resistance. For example, 69 smks with 26.5 gr Vargetvwould function no problem, with no pressure signs. However, anything lighter would short stroke, so I went back to the stock buffer and spring with no problems in functioning.

So, the stock buffervand spring in combination with the heavy bcg and cws have effectively increased the functional range of tolerated loads in my AR, and the ejected rounds end up only two feet away.

 

[jonbearman]

That failure pictured above was more than likely not in full lock-up caused by a high primer forcing it to slam fire.A friend of mine did the same thing and splattered both of us with schrapnel. They dont fail for no reason and would send the whole thing back to whatever company made it for their quality guys to figure out what actually happened.

 

[MT204]

To answer a few questions. The ar is my son's. All top of the line parts. 204 Ruger cal. No one was hurt except for the hood of his suv that he was shooting across. Completely designated the mag. The bolt was locked and was not fired out of battery. In fact in the picture it is still locked. We are not sure what caused this to happen to this very day. Was able to tap the bolt to unlock it to open and remove it. The case was not ruptured. I called the company that mfg the BCG and explained what happened. They asked for pictures which I e-mailed to them. I had a new BCG the next morning ups red label no charge. I have a feeling it was a bad BCG? Should add that this is a "side bolt" ar and was being shot as a single shoot when this happened.

 

[ratguner]

As stated before, they are not all the same.
I use a chrome M16 carrier because:
1) more mass
2) chrome makes cleaning super easy

3 or 4 patches soaked with PB or Liquid Wrench and cleaning is complete!

 

[jonbearman]

You mentioned you used high quality parts,so who made them and that thing could of easily slam fired and bounced the bolt in and out of battery without ejecting the spent case.