construction an Ar-15 - Upper Receiver

When finding for an upper receiver for your Ar-15, it is leading to do your research and note the dissimilar features offered by each company. Although the upper receiver is for an Ar-15, each company has their own highlight set. Straight through my research, I found the Cmmg 14.5" upper receiver to fit my needs the best.

The main conjecture I chose the Cmmg upper was because of its features and price. The faultless upper ran 0, not a bad deal and right at the price point of other close mid-level competitors such as Bushmaster, Stag, Dpms, etc. What sets Cmmg apart is its mid-level price with high-end features.

California Sky Diving

Some of the more noted features include: Chrome lined barrel, 4150 steel 1:7 twist M4 Feedramps 5.56 Chamber.

The chrome lined barrel helps in preventing rust and prolonging the life of your barrel, with the disadvantage of reducing accuracy very subtly vs a stainless steel barrel. On the flip side, chrome lined barrels are very easy to clean and don't need to be cleaned as often. 4150 steel is higher grade, mil spec steel used in combat rifles given to our forces in Iraq. Some mid-level brands use 4140 steel, a slightly lower quality.

The 1:7 twist allows the rifle to shoot heavier rounds. The primary M16 had a 1:12 twist which would only stabilize rounds up to about 55gr. A 1:9 twist barrel (like most mid-level fellowships offer) could allow you to shoot heavier 75 and 77gr rounds, but the stability is iffy from brand to brand. However, the 1:7 twist will stabilize the heavier rounds just fine which makes it perfect for anti-personnel/home defense rounds.

M4 feedramps are debatable as seen in the forum post I linked to. I'm right on target with the author of the post, "if they will preclude one arresting in 1k rounds, and cost Me nothing extra, I want them." However, if you end up finding a good deal on an upper without M4 feedramps, don't let it be a deal breaker. Many people have reported no problems without M4 feedramps, but if you're getting a new rifle, why not get the latest tech?

A 5.56 chamber will let the Ar-15 shoot .223 as well as hotter 5.56 rounds. On the contrary, you should not be shooting 5.56 out of a .223 rifle. This is because 5.56 rounds are loaded to higher pressures than acceptable .223. If you were to shoot 5.56 out of a .223 rifle, you could potentially damage the weapon. The benefit of 5.56 vs .223? For the most part, accuracy is slightly best with the 5.56 and the velocity is slightly higher. Bottom line: I want to be able to shoot hotter loads should I need the stopping power in case of emergencies like a home invasion, Wwiii, 2012, zombies, etc best to be safe than sorry and best to have it and not need it rather than to need it and not have it.

The linked forum thread at Officer.com should help you a whole lot in choosing which upper to get. I'd recommend you to look Straight through the dissimilar brands, weigh the pro's and con's, price and performance, then make your decision. However, if you've got tons of cash and want the best, just get a Colt.

construction an Ar-15 - Upper Receiver