Bolt carrier group

[ajb]

Do all the BCGs in AAC uppers have the AAC logo on them? I bought a used upper and suspect it doesn't have the original BCG. It functions fine so far, just curious.

[pvanwagner]

Yes. The one's from about the last 18 months or so have NB BCGs. All the BCGs NB and the earlier black ones have our logo on them.

[ajb]

Thanks, this one has WIB imprinted on the flat under the end of the gas key. Does that tell anyone anything?

Would it be wise for me to buy an AAC BCG?

Can you tell me anything about the upper from the number stamped on the underside of the barrel?

[Overton-AR]

When are those AAC BCG's going to be available for sale???
I am checking the website every couple days and nothing yet.

[randyrucker]

Hopefully after the Brakeout2 comes out.....

[pvanwagner]

Marketing and the Product Manager are working on both of those. Hopefully soon.

[300Blk]

Thanks, this one has WIB imprinted on the flat under the end of the gas key. Does that tell anyone anything?

Just post a photo of the carrier.

Would it be wise for me to buy an AAC BCG?

That depends on if your current BCG has a problem. You may have an older AAC carrier - and they had no problems.

Can you tell me anything about the upper from the number stamped on the underside of the barrel?

Maybe. If it is a date code and several years old, then it may be an AAC carrier. Does your extractor spring have a green o-ring?

[ajb]

Thanks, this one has WIB imprinted on the flat under the end of the gas key. Does that tell anyone anything?

Just post a photo of the carrier.

Would it be wise for me to buy an AAC BCG?

That depends on if your current BCG has a problem. You may have an older AAC carrier - and they had no problems.

Can you tell me anything about the upper from the number stamped on the underside of the barrel?

Maybe. If it is a date code and several years old, then it may be an AAC carrier. Does your extractor spring have a green o-ring?

http://i246.photobucket.com/albums/gg93 ... C01090.jpg
http://i246.photobucket.com/albums/gg93 ... C01091.jpg



# G013 27943. the o-ring is black.

First try at posting pictures, hope it worked.

[cpatterson86]

http://i246.photobucket.com/albums/gg93 ... C01090.jpg
http://i246.photobucket.com/albums/gg93 ... C01091.jpg

# G013 27943. the o-ring is black.

First try at posting pictures, hope it worked.

Not an AAC carrier. The original owner swapped carriers. That one is not logoed and it is a semi-auto carrier.

[kilibreaux]

There is zero need to buy a purpose-specific, "branded" BCG for the .300AAC unless you simply have money burning a hole in your pocket and want to see a caliber stamp on an internal part.
Breech thrust on the .300AAC and .223 is identical with equal chamber pressures. Breech thrust with authentic 5.56x45 NATO spec is GREATER than that from the .300AAC.
Yes the Blackout is pushing a heavier bullet, but the .223 and 5.56 are pushing their lighter slugs FASTER - by far, which results in approximately the same kinetic energy coming out the barrel...which means both bolts are subject to pressures so close as to be statistically indistinquishable.

I've put 5,000 rounds on my current "garden variety" 8620 steel BCG in my .300AAC and it doesn't even look worn.

Where it MATTERS is when choosing the 7.62x39 or 6.8 Rem SPC which use a larger base diameter. This means greater breech thrust, and the bolt proper must be modified by removing metal around the breechface which weakens the locking lugs. Even though the 7.62x39 operates at significantly lower pressures than the .223 or TOP loaded AAC, AR bolts are not going to last as long due to less lug support.

Also, MOST .300AAC loads are running MILD....especially subsonic loads...