BCM middy upper??? > AR Discussions

Posted: 10/20/2008 8:27:04 PM EDT

Im thinking about buying a middy upper from BCM. Im still new to the AR so i have a question. What else would I need to buy to make it a complete upper? On the website all I can see is missing handguards. Anything else that I need to buy to make it a complete upper?

Posted: 10/20/2008 8:33:11 PM EDT

[#1]

A bolt carrier group and charging handle. BCM also makes the best bolt groups around, IMO.

Posted: 10/20/2008 9:03:49 PM EDT

[#2]

height=8

Quoted:
A bolt carrier group and charging handle. BCM also makes the best bolt groups around, IMO.

Would I need any special tools to install these parts?

Posted: 10/20/2008 9:12:20 PM EDT

[#3]

Quoted:

Quoted:
A bolt carrier group and charging handle. BCM also makes the best bolt groups around, IMO.

Would I need any special tools to install these parts?

NO...you just need opposable thumbs.

Posted: 10/20/2008 9:27:01 PM EDT

[#4]

Quoted:

Quoted:
A bolt carrier group and charging handle. BCM also makes the best bolt groups around, IMO.

Would I need any special tools to install these parts?

NO...you just need opposable thumbs.

With upper and lower recievers attached by forward takedown pin, place charging handle in but still about half way retracted. The bolt should be forward in the carrier when you place the BCG into the upper (gas key into the slot of CH). Then push forward on base of BCG until it and CH lock into place. Close the upper onto the lower and push in rear takedown pin. Voila! Ready to go bang!

P.S. really nice selection on the upper. Want one myself.

Posted: 10/20/2008 9:55:48 PM EDT

[#5]

I have a few more questions about the bolt carrier group. Whats the difference between semi and auto? What does MPI mean? Also right now the only one BCM has in stock is the CMT bolt carrier groups. How good is CMT compared to LMT and BCM carrier groups?

Posted: 10/20/2008 10:20:09 PM EDT

[#6]

Quoted:
I have a few more questions about the bolt carrier group. Whats the difference between semi and auto? What does MPI mean? Also right now the only one BCM has in stock is the CMT bolt carrier groups. How good is CMT compared to LMT and BCM carrier groups?

denny (gts, global tactical) has these bolt/carriers.

Posted: 10/20/2008 10:21:03 PM EDT

[#7]

There's more meat on the bottom of an M-16 carrier, hence more weight. Believe the reason for the alteration was so that a semi-auto BCG will not function properly in a full auto gun for back in the day if you had the knowing and the tools you could convert a semi- to full auto. Had to do with Batfe rulings over a period of time and what defines a full auto gun (bolt carrier, hammer, selector/ safety, disconnector, trigger and auto sear) by ATF definitions. Eventually the ATF acknowledged that the AR series functions better with the mass of a M-16 carrier and the one part by itself doesn't constitute a full auto weapon. Its no longer an issue.
MPI is magnetic particle inspection. Known as magnafluxing in the auto industry to inspect for flaws and defects in metallurgy that may contribute to premature failure of a part.
All of the BCGs you've mentioned are good- some better than others for various reasons. Believe the BCM BCG is a CMT but Bravo takes additional steps (staking keys, shot peening, MPIing every bolt). The LMTs are also MPI'd but the one LMT BCG I've purchased was not staked as well as the BCMs. Not sure about the shot peening. As far as the CMTs I believe that they do not test each and every bolt but sample lots (could be wrong on this). The BCM is hard to beat and would be my first choice followed by LMT and then CMT. Personal opinion.

Posted: 10/20/2008 11:07:09 PM EDT

[#8]

Quoted:
There's more meat on the bottom of an M-16 carrier, hence more weight. Believe the reason for the alteration was so that a semi-auto BCG will not function properly in a full auto gun for back in the day if you had the knowing and the tools you could convert a semi- to full auto. Had to do with Batfe rulings over a period of time and what defines a full auto gun (bolt carrier, hammer, selector/ safety, disconnector, trigger and auto sear) by ATF definitions. Eventually the ATF acknowledged that the AR series functions better with the mass of a M-16 carrier and the one part by itself doesn't constitute a full auto weapon. Its no longer an issue.
MPI is magnetic particle inspection. Known as magnafluxing in the auto industry to inspect for flaws and defects in metallurgy that may contribute to premature failure of a part.
All of the BCGs you've mentioned are good- some better than others for various reasons. Believe the BCM BCG is a CMT but Bravo takes additional steps (staking keys, shot peening, MPIing every bolt). The LMTs are also MPI'd but the one LMT BCG I've purchased was not staked as well as the BCMs. Not sure about the shot peening. As far as the CMTs I believe that they do not test each and every bolt but sample lots (could be wrong on this). The BCM is hard to beat and would be my first choice followed by LMT and then CMT. Personal opinion.

I'd place LMT/CMT in the same category, as LMT extensively tests all bolt carrier groups before shipping. They use a 50% overpowered HP round before MP testing. I would not discount LMT simply because they stake their gas keys "less" than BCM.

CMT now offers MP testing on their bolts. Older MP tested CMT bolts had MP crudely etched in, but now they stamp their MP tested bolts like everyone else.

Posted: 10/20/2008 11:28:42 PM EDT

[#9]

Quoted:

Quoted:
There's more meat on the bottom of an M-16 carrier, hence more weight. Believe the reason for the alteration was so that a semi-auto BCG will not function properly in a full auto gun for back in the day if you had the knowing and the tools you could convert a semi- to full auto. Had to do with Batfe rulings over a period of time and what defines a full auto gun (bolt carrier, hammer, selector/ safety, disconnector, trigger and auto sear) by ATF definitions. Eventually the ATF acknowledged that the AR series functions better with the mass of a M-16 carrier and the one part by itself doesn't constitute a full auto weapon. Its no longer an issue.
MPI is magnetic particle inspection. Known as magnafluxing in the auto industry to inspect for flaws and defects in metallurgy that may contribute to premature failure of a part.
All of the BCGs you've mentioned are good- some better than others for various reasons. Believe the BCM BCG is a CMT but Bravo takes additional steps (staking keys, shot peening, MPIing every bolt). The LMTs are also MPI'd but the one LMT BCG I've purchased was not staked as well as the BCMs. Not sure about the shot peening. As far as the CMTs I believe that they do not test each and every bolt but sample lots (could be wrong on this). The BCM is hard to beat and would be my first choice followed by LMT and then CMT. Personal opinion.

I'd place LMT/CMT in the same category, as LMT extensively tests all bolt carrier groups before shipping. They use a 50% overpowered HP round before MP testing. I would not discount LMT simply because they stake their gas keys "less" than BCM.

CMT now offers MP testing on their bolts. Older MP tested CMT bolts had MP crudely etched in, but now they stamp their MP tested bolts like everyone else.

I'm not discounting them. As was previously stated they are all good. From my understanding the BCMs are CMTs. As for the staking the BCMs are staked properly but the LMT had a kind of pressed cut across the key bolts and top surface of the carrier. All in all the BCMs seem to offer the same as the LMTs with a bit more attention given to properly prepping them for use. If I needed another BCG and couldn't wait for a BCM I wouldn't hesitate to purchase the LMTs (have 3 complete LMT guns). I wasn't saying anything bad about any of them, just expressing my druthers...
So you are saying that the CMTs 'offer' MPIing as an option and that its not a regular routine testing done on their bolts?

Posted: 10/21/2008 7:57:14 AM EDT

[#10]

Double tap

Posted: 10/21/2008 7:58:29 AM EDT

[#11]

What you need is:
Upper receiver
Handguards or 9 inch rail
Bolt carrier group (get a auto/m16)
Charging handle
You can probably order all this stuff from GTS/ Denny's Gun and they might even install the rail if you ask.

I just got a BCM midlength.
Added a Daniel Defense Omega rail, Gasbuster charging handle, BCM BCG.
Very happy

Posted: 10/21/2008 8:35:39 AM EDT

[#12]

My BCM middy is due on Friday, with LMT BCG. Gonna add some Troy rails and gas block, stick it on an LMT lower with a Trijicon TA01NSN

Posted: 10/21/2008 8:57:21 AM EDT

[#13]

My BCM middy shipped UPS ground yesterday, so I hope to have it Thursday. I like the Omega rails, but that is more than I want to spend. What other options are out there other than plain guards? I plan on just putting iron sights on, so it is a KISS weapon for now.

Posted: 10/21/2008 9:45:22 AM EDT

[#14]

height=8

Quoted:
There's more meat on the bottom of an M-16 carrier, hence more weight. Believe the reason for the alteration was so that a semi-auto BCG will not function properly in a full auto gun for back in the day if you had the knowing and the tools you could convert a semi- to full auto. Had to do with Batfe rulings over a period of time and what defines a full auto gun (bolt carrier, hammer, selector/ safety, disconnector, trigger and auto sear) by ATF definitions. Eventually the ATF acknowledged that the AR series functions better with the mass of a M-16 carrier and the one part by itself doesn't constitute a full auto weapon. Its no longer an issue.
MPI is magnetic particle inspection. Known as magnafluxing in the auto industry to inspect for flaws and defects in metallurgy that may contribute to premature failure of a part.
All of the BCGs you've mentioned are good- some better than others for various reasons. Believe the BCM BCG is a CMT but Bravo takes additional steps (staking keys, shot peening, MPIing every bolt). The LMTs are also MPI'd but the one LMT BCG I've purchased was not staked as well as the BCMs. Not sure about the shot peening. As far as the CMTs I believe that they do not test each and every bolt but sample lots (could be wrong on this). The BCM is hard to beat and would be my first choice followed by LMT and then CMT. Personal opinion.

So does it really matter if I choose Semi over Auto? Is there any big difference?

Posted: 10/21/2008 9:56:24 AM EDT

[#15]

So does it really matter if I choose Semi over Auto? Is there any big difference?

Your choice.

Posted: 10/21/2008 12:21:10 PM EDT

[#16]

I've got my BCM middy upper.
My BCM auto BCG just showed up today.
I've got the LaRue BUIS.
I've got handguards coming from another member.
My lower is complete, waiting to be crowned with the upper.

Quoted:

Quoted:
There's more meat on the bottom of an M-16 carrier, hence more weight. Believe the reason for the alteration was so that a semi-auto BCG will not function properly in a full auto gun for back in the day if you had the knowing and the tools you could convert a semi- to full auto. Had to do with Batfe rulings over a period of time and what defines a full auto gun (bolt carrier, hammer, selector/ safety, disconnector, trigger and auto sear) by ATF definitions. Eventually the ATF acknowledged that the AR series functions better with the mass of a M-16 carrier and the one part by itself doesn't constitute a full auto weapon. Its no longer an issue.
MPI is magnetic particle inspection. Known as magnafluxing in the auto industry to inspect for flaws and defects in metallurgy that may contribute to premature failure of a part.
All of the BCGs you've mentioned are good- some better than others for various reasons. Believe the BCM BCG is a CMT but Bravo takes additional steps (staking keys, shot peening, MPIing every bolt). The LMTs are also MPI'd but the one LMT BCG I've purchased was not staked as well as the BCMs. Not sure about the shot peening. As far as the CMTs I believe that they do not test each and every bolt but sample lots (could be wrong on this). The BCM is hard to beat and would be my first choice followed by LMT and then CMT. Personal opinion.

So does it really matter if I choose Semi over Auto? Is there any big difference?

Being that they run the same price, and there's no negative with the auto, I'd say go that route.

Posted: 10/21/2008 3:16:04 PM EDT

[#17]

Quoted:
My BCM middy shipped UPS ground yesterday, so I hope to have it Thursday. I like the Omega rails, but that is more than I want to spend. What other options are out there other than plain guards? I plan on just putting iron sights on, so it is a KISS weapon for now.

I was looking at some Midwest Industries non free float rails, about $148.50 at Bravo Company. They are pretty solid.

Posted: 10/22/2008 7:16:35 PM EDT

[#18]

Bravo Company USA Mid-Length upper info:

www.ar15.com/forums/topic.html?b=3&f=12&t=394539

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