AR-15 Bolt Carrier Group Comparison

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This is a comparison of some of the differences in the many AR-15 bolt carrier groups. Represented here are three different companies: S&W, Bushmaster, Stag Arms.

The comparison is based off of these items:
1: Properly Staked Gas Key
2: M16, AR-15 Enhanced, and AR-15 Bolt Carrier (Mass of Bolt Carrier)
3: Extractor Spring Included (Black vs Blue)
4: Shot Peened Bolt
5: (HPT) High Pressure Tested
6: (MPI) Magnetic Particle Inspection

My order of preference in BCGs are:
1: M16/Full Auto
2: AR-15 Enhanced
3: AR-15
4: Semi-circle AR-15

It is important to note that in carbine length gas systems the heavier BCGs are going to reduce cycle time enough to reduce wear to the internal parts of the receiver and BCG itself.

Hope you found this interesting...Thanks for watching!


Copyright 2011 DocTacDad

Category:

Education

Tags:

• bcg
• bolt
• carrier
• group
• ar15
• ar
• ar-15
• S&W
• cm
• continental
• machine
• Stag
• arms
• bushmaster
• 223
• 556
• tactical
• shot
• peening
• hpt
• magnetic
• particle
• inspection
• edc
• shtf

[ms3bani]

shot peening doesn't change the molecular structure of anything. it just reduces stresses from manufacturing processes, making it more resistant to fatigue vs a non shot peened part.

[DocTacDad]

@ms3bani Go ahead and explain how you can change the resistant properties to fatigue in metal and not change it molecular structure...because I SUPER curious as to how that works.

[DocTacDad]

@ms3bani (respectfully) The definition of "Molecular" structure in metals refers to the crystalline structure of the molecules or atoms in said metal. You cannot change the resistive properties of a metal without changing the crystalline structure (molecular structure). Peening produces a molecular change to the surface of the metal by creating a compressive stress layer. What you are failing to understand is that it is essentially a MOLECULAR/CRYSTALLINE structural change that accomplishes this

[ms3bani]

@DocTacDad

metal has no molecules, so there is no molecular structure. again, there's nothing more amazing here than what happens with a spring. it's a useful engineering technique but there's no need to dress it up.

you can change the resistive properties of a metal by changing its temperature... this does not change its atomic structure at all.

[DocTacDad]

@ms3bani I will consed that there are no molecules inside of the steel, but to say that shot peening doesn't change the atomic/crystalline arrangement is nonsense, And yes temperature will change the structure of the metal and it's contained impurities...hence the reason for heat treatments.

[jimbrady1776]

Am I suppose to buy a new S & W rifle instead of an old Bushmaster carbine? Because I can't imagine anyone picking a gun based on one easily replaceable component. Dude, the older Bushmaster bolt carrier has obviously been tampered with. Look at how the gas key bolts have been turned and not torqued back fully. And if you have a carbine, you want the lighter bolt because you don't have the same pressure impulse being generated by the gas system. I would much rather have a gun function.

[DocTacDad]

@jimbrady1776 Actually, the carbine length generates a greater pressure impulse due to the gas port being Located closer to the chamber where the pressures are higher. The gas key on the older bushmaster has never been tampered with.

[joezbackwith2gatz]

Great job on this video... Very helpful. I think Mr.Stoner would be proud. I have a few stags and they are made well(4L-6L-8L). Stag says they are milspec but who knows...LOL... I know they shoot and if they stop they will have to repair or replace them. I am a lefty so I am very limited. Does anyone know of another company besides Stag and rockriver that makes some after market lefty BCG? Thanks again for making this video. It's like I always say. Let's all learn from each other. Joe Tactical

[KniveGun2ndAmmend]

Nice vid, but damn are you white!

[ThermalSh0ck]

also @ 7:10 my stag bolt isn't that thin and neither are the ones on every other stag i have seen, are you sure it was a stag bolt, maybe stag makes them different now cause the S&W bcg looks like my stag bcg

[ThermalSh0ck]

My stag was staked like the newer bushmaster bcg you showed. That's odd.

[andrewquinn308]

Meat is cut off the rear of the carrier to not allow full auto fire from an AR15. when your equipment gets bent or wore replace it.

[GUNS4MIKE1234]

@boredinthebox1 Um for someones who puts there life in the hands of there weapon everyday your really that stupid to never even think about it? Why do you care anyways you should know that you have a full auto bcg anyway it's a basic review of whats the best why does he need to go out and shoot them all right now? You really need to realise that this stuff matters for you it really should anyway but w/e it's your life not mine.

[GUNS4MIKE1234]

I have a full auto carrier group in a century ar-15 it has a original colt upper with a new barrel 1 in 9 twist and the lower I think was cmmg or dpms century just puts them together shoots great I Love the old a1 rear sight too.

[boredinthebox1]

Holly shit!!! DUDE!!! Stop being a gear slut and go shoot! I have never once looked at the BCG in my M4 I have taken to Iraq and AFG and here you are talking about the weight of an enhanced BCG? Are you kidding me? Dude, its a couple of grams!!!!! GO SHOOT!!!!!!! Compare them all, do you REALLY see a difference? The amount of time you spent on this topic is amazing to me. Good vid and some what useful info, but go shoot man. Get out of the house and wear those BCG's out and then do a review.

[jmmurdy]

This is one of your better videos good job.