If I were to buy an Upper not build one that Palmetto would be hard to beat.
It has a great list of features that are very desirable, and IMO a great value for $550
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I will apologize now for the long post, but I think a newbie should be informed on these things, I wish I was told this stuff when I got my first AR.
here are the great parts of that Palmetto, and the CDNN only shares a few
1. the FN made Cold hammer Forged, chrome lined 5.56 barrel that is HPT (high pressure tested) and MP (magnetic particle) inspected, that ensures that there are no nasty suprises in the metallurgy. Its pretty well known that FN makes great barrels, our military uses them, and most agree Cold hammer forged produces great barrels.
CDNN doesnt say what the barrel is or where it came from pretty sketchy.
2.The upper is made from 7075 T6 aluminum not the cheaper and weaker 6065 T6 that the CDNN most likely uses, and the upper has M4 feed ramps cut to match the barrel extension. The m4 feed ramps aid in feeding rounds at high rates of fire. The CDNN does not list material specs or if it has m4 feedramps.
3. The Bolt carrier group an M16 style bolt or "full auto" style, that means it has more material on the lower rear portion of the carrier and therefore is slightly heavier, its also has a shrouded firing pin.
The extra mass of the m16 carrier slows the action down, and produces a softer recoil impulse, and greatly reduces bolt bounce . Bolt bounce is when the bolt slams into the receiver extension with too much speed. Instead of locking and staying locked, It rebounds out of the receiver extension slightly, that partially unlocks the bolt, then it is pushed back to the fully locked position by the recoil spring, That crates a harsh recoil impulse and wears parts faster, specifically the cam track, cam pin ,and the receiver. For full auto guns that can be a problem with a possibility of an out of battery detonation. Its rare but it is an issue. For semi autos is just a wear issue not unsafe.
The AR15 bolts have most of the material on the bottom rear of the bolt carrier removed, they are "neutered" so there is only a small portion at the rear of the carrier that is a complete circle making it impossible for the AR-15 carrier to work in a full auto gun.
The M16 bolt has about an inch and a half more material on the bottom rear of the carrier, leaving a hole just big enough for the hammer. that extended lower rear section of the M16 "auto" carrier is necessary to trip the secondary disconnector for auto and burst fire. semi autos are missing that extra disconnector.
AR-15 bolts are more susceptible to carrier tilt, that speeds up receiver wear and do not have a shrouded firing pin. The CDNN certainly has an AR15 carrier even though they dont say.
The shrouded firing pin makes for a smoother action and, there is a large steel ramp that is part of the bolt carrier that depresses the hammer into the firing position, an AR-15 bolt does not have this ramp so the Firing pin re cocks the hammer, and can occasionally hiccup at that point while the bolt moves forward. That puts alot of strain on the retaining pin and can eventually bend it to the point of failure.
But realistically that is a non issue for 99% of civvies. But if you can get the M16 carrier in the deal its great.
4. The Bolt is Nickel Boron Coated MP and proof tested ( deliberate overpressure rounds fired to test strength) and after that they MP test for microscopic fractures or deformation.
NB coatings and HPT/MP testing are expensive, an NB bolt is generally $50-$100 more than a parkerized bolt.
And individual part HPT and MP testing certainly adds cost.
Nickel Boron is a very hard and slippery coating that is rust and wear resistant, it also makes cleaning a breeze because of the smooth surface, compared to a porous parkerized bolt. You can just wipe off the carbon on a Nickel Boron bolt.
Supposedly Nickel Boron requires less oil, but I have not found that to be true, if anything it needs a little bit more oil because the coating does not "hold onto it" like parkerized parts do
CDNN doesnt even list what bolt is its made out of sketchy!
5. The 5.56 chambering in itself, manufacturers say not to shoot 5.56 out of a .223 marked gun because although they are the same bullet and case, the 5.56 is running at a higher pressure. I dont buy that at all for reasons I wont go into, but its a non issue since its a 5.56 barrel. CDNN is 5.56 as well.
6.The 1-7 twist of the barrel is perfect, it will stabilize everything from 55gr XM193 surplus to the heaviest 77gr MK262 rounds and clones. One thing to watch out for is it probably wont stabilize bullets designed for varmint hunting so 55gr is the lightest you may be able to use . But dont worry the 55gr XM193 and .223 varmint loads do some serious damage to large pests like 5lb Groundhogs even out at 300-400yds and using 68-77gr heavy match loads is even better for those **** groundhogs . CDNN says nothing about twist rate.
7. The Midlength gas system is perfect for 14.5-16" carbines, Its much softer shooting than the short carbine length gas system and it runs slightly cooler due to the longer gas tube, and lower pressure at the gas port.
The mid length handguards are a little longer so its more comfortable and easier to use a light, you probably wont need a cantilever light mount.
The listing says a low profile gas block but shows an A2 sight so I am confused at that.
A low profile gas block is desirable so upgrading to a free floated rail in the future will be alot easier and cheaper, since you wont have to buy a low profile gas block and remove the A2 FSB.
I suspect it is a A2 front sight, becuase there is no provision to mount a front sight on the Magpul handguards. That is not strictly a bad thing, the A2 sight wont break, and all you need is a flipup rear as a backup to optics or any one of the great fixed rear sights, if you want irons only.
CDNN has a low profile gas block and is already free floated. But has a heavy, bulky, uncomfortable, and way out of date quad rail. I reccomend you avoid them like the plauge. Quad rails have 50 times the rail space anyone could ever need, even with lights lasers and nightvision, a handguard with a full top rail and two small 3" side and bottom rails is more than enough space.
8. The Magpul Furniture of the Palmetto is perfect for a light handy carbine, the MOE stock and Handguard, and MOE pistol grip are tough,ergonomic, pretty lightweight, and have a great track record with tons of shooters. There are also a ton of accessories for the Magpul stuff, grip inserts for different storage options , light mounts for the handguard, and a thicker squishier buttpad for the MOE stock. I have all of the addons I listed above, love the oil bottle insert for the grip, I also have a parts kit insert. I have the enhanced buttpad, and I have rail sections and a cantilevered flashlight rail section and the cantilevered flashlight mount. All Magpul products and all great.
9. The trigger group on the Palmetto is an enhaced GI trigger that has been polished up and nickel coated to lighten the trigger pull and reduce stacking and creep. Perfect trigger for a Carbine, heavy enough to be safe, and provide a hard hammer fall for military primers. But still light and smooth enough for marksmanship CDNN is just a standard creepy heavy GI trigger
10. Last but not least the barrel profile. PSA does not say what it is but It looks like a "pencil" barrel, thats the thinnest lightest profile available, the barrel is probably only 26oz, that means the gun will be light and fast transitioning to different targets. The profile is both good and bad. That barrel is probably very accurate, and with the right load 1moa is not unreasonable. I have a 14.5 inch Spikes tactical barrel at 22oz and it is very accurate, I get 1-1.25 moa with 77gr SMK loads. It does "open up" a little when it gets very hot, 2 moa with match ammo and 2.5-3 moa with 55gr ball. But that is with a free floated barrel, so no external force is influencing it.
That upper is not free floated so any pressure you put on the handguard will effect accuracy when the barrel gets really hot and a little flexible. But pencil barrels cool very quickly.
All in all as you can probably tell I think the Palmetto Upper kit is far superior to the other one, and I did some looking at a bunch of other manufacturers, and IMO that Palmetto upper and parts kit is one of the best values out there.
What you get at a sub $600 price point is pretty great, the barrel and bolt alone easily cost $350-400 if you were to buy them separately.
Buying a cheap 7075 T6 lower on sale for $115 allows you to have a great rifle for around $700
Again I apologize for such a long post, I hope you find this information helpful.