Upper questions

J

jproaster

New member
Ok, I have my lower; stock and lpk are on the way. My thoughts have been to do two uppers- 5.56 and 6.8. Again, I'm new to the AR and really rifles in general. So, I'm still learning about barrel lengths, rifling, etc. The purposes for the uppers are 5.56- range and general defensive weapon; and with the 6.8 I'd like to hunt (deer and hogs).

With that in mind, I have a few questions:

Since I can only afford to build one upper at a time, which first?
Why choose 5.56 over 223 and why 6.8 over 6.5? Or am I wrong?


Thanks for your thoughtful replies. After I take the plunge on an upper, I suppose the next issue would be bcg and sights.

john

btw, I will be reloading within a couple months.
 
As far as 5.56 and .223, reloading equipment is found every where for cheap for the .223. Can't say much found in the 5.56 nato reloading. Of course have not looked much. Either round is generally good out to 500ish yards with accuracy depending on training/skill level and equipment. (match grade vs in house quick production").

For the 6.8 vs 6.5, again I would suggest a search of reloading availability and compare the ballistic co-efficient. My quick but NOT thorough search shows 6.5 to be more popular and there fore might be easier to get the hands on. Again training/skill and equipment. Within 200 yards a factory barrel is cost effective and defiantly gets the job done.
Hope this direction of thought helps.
 
My vote goes with a good AR in 5.56. I second the recommendation on the Wylde chambering, it's done good things for my LaRue. The 5.56 will also be able to handle .223 ammo, which is far more readily available than either 6.5 or 6.8, which means more practice with (relatively) cheaper ammo. even if you don't reload.
 
A quick review of your state's hunting regulations will show what is considered a minimum caliber requirement for hunting. Some states do not allow 5.56.

The better caliber for hunting would be one of the 6.+ mm cartridges, as they have more power and lethality. Some research will show the reality of which has more industry support, based on actual popularity in sales. In about a 5 to 1 ratio.

In either case, you would be better served with the 6.+mm upper for hunting - but general plinking, which uses a lot more ammo, the dirt cheap price of a military surplus caliber shines.
 
I don't know what all equipment you are looking at, but remember a 5.56 will fire .223 but not always the other way around. 5.56 NATO is loaded or can be loaded to higher SAAMI specs.
 
Thanks for the replys- public and private. I'm still curious why someone would choose a 223 vs 5.56 and why would one choose either the 6.5 vs 6.8?

john
 
There is no such thing as "reloading equipment for a 5.56". While reloading manuals may give data for 5.56 type loads, the reloading dies themselves are the same as .223. If you're just getting started, don't confuse yourself with the 223 vs 5.56 thing. Get a rifle with a 5.56 chamber or the Wylde version(a compromise between the two) and just shoot it.
When the funds are available, you can add another upper of your choice. I looked closely at the 6.8 and decided it wasn't really what I wanted. My pick for a deer caliber AR is the 7.62x39 based on two features:cheap, readily available ammo and the fact that I already had the upper.
 
Good point about the .223/5.56 - they use the same components and dies. The chamber is about the only difference. 7.62x51 and .308 are in the same boat, although strangely, the civilian .308 is the slightly hotter load.

Nothing wrong with choosing ammo based on non-ballistic issues, we all do it. In this case, the OP was buying - and the ballistics seem to be in question. He needs to decide for himself which offers the optimum performance at the range and target intended.

In the case of x39 ammo, cheap wouldn't count in hunting, many states make the FMJ ammo illegal to use, and good hunting ammo is anything but cheap. A properly designed expanding bullet for use on game out to 500m max in the AR15 is likely 85 to 130 grains, traveling from 2600 to 3100 fps. All three of the cartridges, 5.56, 6.5G, and 6.8 can do that. What range most commonly encountered can help understand what barrel length is preferred, and what weight bullet to send downrange. The OP needs to fill in the blanks and decide, we have no idea what is important as it hasn't been specified.

At this point in time, buying into the x39 upper wasn't asked about, and since it uses a dogleg magazine that no one can make reliable, I don't see it as a viable choice except for plinking cheap ammo at dirt. X39 is less powerful than .30-30, the alternate calibers mentioned have characteristics such as more reliable feeding and better downrange performance that many prefer. Hunting ammo costs are all within pennies a round.

Good example why I'm NOT telling the OP which is best - there are considerably divergent opinions on the subject. Let him study up and make up his own mind for what he wants to do.

It works OK if you already had the upper, I'm no stranger to frugality. Since my AR build was open to caliber and financed entirely by selling off other unused stuff, like the OP, I could consider which caliber better suited my purposes. Like as not, side by side, deer would be equally dead. The cost of a couple of boxes ammo every year didn't even figure in.
 
Thanks guys for the replies. As for which upper, I think the 5.56 will come first- not sure when I'd be reloading. and it gives me time to think through the second upper's caliber.

Time to search for a 5.56 upper.

Thanks for the links Tirod; will definitely be reading those.

john
 
C0untZer0 said:
I don't know what all equipment you are looking at, but remember a 5.56 will fire .223 but not always the other way around. 5.56 NATO is loaded or can be loaded to higher SAAMI specs.
Click to expand...

Just to clarify, the pressure of a 5.56 NATO round isn't measured the same way a .223 Remington round is, so they can't be compared directly to one another. However, generally speaking, 5.56 NATO is usually of a higher pressure than .223 Remington.

5.56 NATO and .223 Remington ammunition is dimensionally the same. The chamber in a gun is what is different. 5.56 NATO has a longer leade or freebore as opposed to .223 Remington.

Not trying to be a wise guy or nitpick at what you said, I just wanted folks to know the difference between the two rounds.
 
Freebore/leade is the unrifled section of barrel just ahead of where the bullet could touch if the rifling extended back a few thousandths further.

In general, precision guns tend to use very little leade, as it helps to center the bullet in the lands. During ignition of the primer, the bullet jumps a bit forward in the case, and having a short leade reduces the possibility it tilts off axis, which helps the bullet down the bore and exit the barrel on the same axis. It also doesn't wobble as much in the early stages of flight, both of which keep it closer to the point of aim.

On the other hand, more leade allows hotter loads, as there is less pressure spike at the onset of full combustion. In the 6.8SPC, lengthening the leade from .050 to .090-.100 dropped peak pressures 5,000 pounds and increased FPS because the chamber allowed more powder to be used to reach the maximum. In some cases, it allows handloaders to chronograph 3,050 FPS from 16" barrels with sub 100gr bullets. The tradeoff is that other ways have to be used to retain accuracy, ie, keep the bullet co-axial to the bore and prevent it from cocking as it travels down it out the barrel. Long leades are known to be slightly less accurate.

In the case of 5.56, more power was important, but accuracy of 2MOA is all that is needed for combat. It puts the bullet into a ten inch circle at 500m, plenty accurate enough on the 18" square presented by the upper torso of humans.

Designers trade off one area to gain in another, the basic constraints of cartridge design mean you can't have it all, no way can things be optimum in every characteristic. Every cartridge design has compromises and offsets which create it's intended optimum use. Deliberately deviating from that to do something that wasn't intended is typical, and a source of much discussion.
 
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Thanks for elaborating on the details guys. I love learning about this stuff.

Tirod- thanks again for the links and site suggestions. I've read an awful lot online. To choose my upper I am looking to read about barrel lengths and materials. What are the other key factors that I may research those too?

thanks,
john
 
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