| When looking for an upper receiver for your | | | | heavier rounds just fine which makes it perfect |
| AR-15, it is important to do your research and | | | | for anti-personnel/home defense rounds. |
| note the different features offered by each | | | | M4 feedramps are debatable as seen in the |
| company. Although the upper receiver is for an | | | | forum post I linked to. I'm right on target with the |
| AR-15, each company has their own feature set. | | | | author of the post, "if they will prevent one |
| Through my research, I found the CMMG 14.5" | | | | stoppage in 1k rounds, and cost ME nothing extra, |
| upper receiver to fit my needs the best. | | | | I want them." However, if you end up finding a |
| The main reason I chose the CMMG upper was | | | | good deal on an upper without M4 feedramps, |
| because of its features and price. The complete | | | | don't let it be a deal breaker. Many people have |
| upper ran $550, not a bad deal and right at the | | | | reported no problems without M4 feedramps, but |
| price point of other close mid-level competitors | | | | if you're getting a new rifle, why not get the |
| such as Bushmaster, Stag, DPMS, etc. What sets | | | | latest tech? |
| CMMG apart is its mid-level price with high-end | | | | A 5.56 chamber will let the AR-15 shoot .223 as |
| features. | | | | well as hotter 5.56 rounds. On the contrary, you |
| Some of the more notable features include: | | | | should not be shooting 5.56 out of a .223 rifle. This |
| Chrome lined barrel, 4150 steel 1:7 twist M4 | | | | is because 5.56 rounds are loaded to higher |
| Feedramps 5.56 Chamber. | | | | pressures than standard .223. If you were to |
| The chrome lined barrel helps in preventing rust | | | | shoot 5.56 out of a .223 rifle, you could potentially |
| and prolonging the life of your barrel, with the | | | | damage the weapon. The advantage of 5.56 vs |
| disadvantage of reducing accuracy very subtly vs | | | | .223? For the most part, accuracy is slightly |
| a stainless steel barrel. On the flip side, chrome | | | | better with the 5.56 and the velocity is slightly |
| lined barrels are very easy to clean and don't | | | | higher. Bottom line: I want to be able to shoot |
| need to be cleaned as often. 4150 steel is higher | | | | hotter loads should I need the stopping power in |
| grade, mil spec steel used in combat rifles given | | | | case of emergencies like a home invasion, WWIII, |
| to our troops in Iraq. Some mid-level brands use | | | | 2012, zombies, etc Better to be safe than sorry |
| 4140 steel, a slightly lower quality. | | | | and better to have it and not need it rather than |
| The 1:7 twist allows the rifle to shoot heavier | | | | to need it and not have it. |
| rounds. The original M16 had a 1:12 twist which | | | | The linked forum thread at should help you a |
| would only stabilize rounds up to about 55gr. A 1:9 | | | | whole lot in deciding which upper to get. I'd advise |
| twist barrel (like most mid-level companies offer) | | | | you to look through the different brands, weigh |
| could allow you to shoot heavier 75 and 77gr | | | | the pro's and con's, price and performance, then |
| rounds, but the stability is iffy from brand to | | | | make your decision. However, if you've got tons |
| brand. However, the 1:7 twist will stabilize the | | | | of cash and want the best, just get a Colt. |