Quality upper on top of mid-grade lower/bolt?

[SpookyPistolero]

Howdy folks-

I was hoping you all could help me with a dilemma! I am gearing up to revamp my AR with a new 16" midlength upper from bravo company, in addition to a few other alterations (stock, light, etc). My current 18" rifle is all made by Double Star, however. This includes my lower parts and bolt/carrier.

So the question is, am I shooting myself in the foot by putting a quality upper on a middle-of-the-road lower? Would the lower parts kit include parts that would be detrimental to reliability in any way? (Not including trigger pull quality).

I know the answer is usually 'just save up and get the good stuff'. But I've got a finite budget, like many, and still have to worry about ammo, range fees, training costs, etc.

Thanks for any thoughts!

[djegators]

I wouldn't worry about the lower or LPK so much, but I would pay the extra $140, and get the BCG with the BCM upper.

[SpookyPistolero]

Thanks, why do you say to get the new BCG? Or what improvements are there on theirs? (Certainly not being argumentative, just wanting to learn what defines quality)

[djegators]

The BCM is one of the best, built to the highest standards, and milspec.

This from the Bravo site:


BCM� (MPI) complete bolt carrier group is fully assembled.

Bolt carrier group (auto version) for your AR15, M16, or M4. Parkerized exterior and chrome lined inside carrier. Machined to USGI specifications. This M16/M4 carrier includes the proper Mil-Spec gas key. Gas key is chrome lined and heat treated per GI specifications. Gas key is secured to carrier via USGI domestic mfg Grade 8 fasteners and properly staked per Mil-Specs. These properly hardened parts insure a strong staking and proper gas system functioning.
The bolt assembly is machined from the correct Mil-Spec Carpenter No. 158� steel, shot peened for increased strength, includes tool steel machined extractor and ejector, BCM Extractor Spring, and is HPT (High Pressure Tested) and MPI (Magnetic Particle Inspected).



Features

* Milspec Carpenter No. 158� steel
* HPT Bolt (High Pressure Tested/ Proof)
* MPI Bolt (Magnetic Particle Inspected)
* Shot Peened Bolt
* Chrome Lined Carrier (AUTO)
* Chrome Lined Gas Key
* Gas Key Hardened to USGI Specifications
* Grade 8 Hardened Fasteners
* Key Staked Per Mil-Spec
* Tool Steel Extractor
* BCM Extractor Spring
* Black Extractor Insert
* Mil-Spec Crane O-Ring


In my opinion, well worth the $140.

[PrivateCitizen]

The BCM is one of the best, built to the highest standards, and milspec.

This from the Bravo site:


That is a lot of specs that basically work out to:

Generally speaking the most issues with a rifle function that are not maintenance, mag, or ammo related are with the BCG I'd wager. SME, correct me if I am incorrect.

The Carrier/Bolt would be a priority to be replaced, even before rest of your upper, IMO.

Once you get the upper and BCG I'd probably ensure my buffer/spring were quality (and a reasonably cheap fix).

Lower and LPK are reasonably last on the upgrade list.

Enjoy the Middy!

[twitch1706]

Many people are of the mindset that a lower is a lower, as long as it is in-spec. If it doesn't give you any issues as-is, I don't think you'll experience any issues with a new upper up top.

The only issue you may come into is if you use your current bolt in the new upper... Supposedly putting an old bolt into a new upper CAN affect headspacing. Mind you, this is something that is fairly often spoken of and rarely seen (at least in my limited experience) but still something to consider. On that same thread, if you don't want to drop the coin on an entirely new BCG, just grab a new bolt and use the DoubleStar carrier.