Buying My First AR...?

[KHEINZ01]

Hey all. I am interested in the purchase of an AR style rifle. Unfortunately, I have always been involved with pistols and never messed around too much with the tactical carbines out there. I will likely be piecing together my rifle with parts that I can find around town or parts from Gunbroker.com. Does anybody have any thoughts on this plan? I was also curious to know exactly what parts affect the caliber designation of the rifle? For example, can a lower receiver be farely universal based on calibers so that I could change out the barrel and upper receiver for a different cartridge? I only ask for the purposes of "plinking" with a .223 but the laws in Arizona say that I can't hunt big game with that cartridge. That said, I would like to know what would be required to convert from .223 to .308. If anybody has any good resources on the web to answer some of these basic questions. Please let me know your thoughts. Brand preferences would be appreciated but I am somewhat on a budget. I apprciate anybody's input on this topic. Thanks to all!

[The Rabbi]

Go to www.ar15.com and learn more than you ever wanted to know. KNow the difference between .223 Remington and 5.56NATO? Me neither, but you can find out there.
I put together my own carbine. It isnt a way to save money, if that's what you're after. Best way to do that is to buy the lower and then buy an upper. The lower of course is the firearm, the upper is just an accesory. Try Model 1 Sales or JT Sales.
As for calibers, I don't think a lower chambered for .223 will convert to .308, or vice versa. The standard conversions for the .223 are:
9x19
.45acp
7.62x39
.50 Beowulf (or is that Grendel?)
and I think the new .450 Bushmaster. I've probably missed a couple.
If you piece the gun together there is an inevitable "mission creep" ("ooh, adjustable gas block--kewl! Ooh, stainless bolt carrier--gotta have") and economy goes out the window.
As far as I can tell, all ARs are basically the same and differ only in features (rails, midlength blocks, flat tops, sights, butt stock configurations etc). So whether the lower receiver has a pony on it, a snake on it, a lion on it, they will all perform the same way.

[vaportrail.308]

It's a good plan if you want to personalize your rifle without spending more than necessary. If you just want a plain jane AR without gizmos I would suggest simply buying a complete rifle. I've priced it out before and it adds up equally.
Unfortunately, the 5.56 and the 7.62x51 lowers are entirely different. You would have to get a dedicated .308 for hunting or use a 7.62x39 upper on your AR15 lower. It's pretty simple, just switch the upper and you're ready to go. The magazines already have adaptors for the AR mag well.



TGZ can explain the differences better than I. http://www.thegunzone.com/556v223.html
As I understand it, DPMS marks their barrels .223 but chambers them for 5.56. I've run about 500 rounds of Malaysian surplus through my DPMS upper without issue. No kB yet...

[The Rabbi]

On the .223 vs 5.56 there is some difference in headspacing I think (overly full detailed explanation on www.theammooracle.com). The .223 will chamber the 5.56 but there is some loss of accuracy. I think there might be some issue going the other way. I opted for a .223 Wylde chamber on mine, which is midway between the two so probably has the worst of both worlds.

[jwise]

You can get a plain jane (high quality) AR in 5.56NATO for ~$750. Any less than that and you're buying shoddy parts, or buying used (which is perfectly fine.)

I would get a second upper in 6.8mm SPC to use for hunting. Great ballistics and it should be fine to hunt with in any region. It has a power factor around that of a 7.62X39 but with better ballistics.

Google "Eagle Firearms" and look at their branded components and Stag components. Or go to www.cmmginc.com and buy with confidence.

[jwise]

You got good advice from the Rabbi.

[H116]

You can get a plain jane (high quality) AR in 5.56NATO for ~$750. Any less than that and you're buying shoddy parts, or buying used (which is perfectly fine.)

I would get a second upper in 6.8mm SPC to use for hunting. Great ballistics and it should be fine to hunt with in any region. It has a power factor around that of a 7.62X39 but with better ballistics.

Google "Eagle Firearms" and look at their branded components and Stag components. Or go to www.cmmginc.com and buy with confidence.

JWISE speaketh the truth....... seen people get center punched with the 5.56 and dash to cover, leaving shooters wonder if they missed. .308 on the other hand.... (stung by bee VS kicked by horse)

[Nightshift va]

You dont know but you want to combine uppers and lowers? If you are lawenforcement Bushmaster has good prices and the quality is great. Also DPMS ARMALITE OLYMPIC AND ROCK RIVER. SMITH also has a new M4

[zeplin]

I would get a second upper in 6.8mm SPC to use for hunting. Great ballistics and it should be fine to hunt with in any region. It has a power factor around that of a 7.62X39 but with better ballistics.

jwise, can you use 5.56 mags with the 6.8 or do you have to have different mags? same mag for both

What particulars about the barrel do you suggest?

[SoCalSheriff]

The .223 will chamber the 5.56 but there is some loss of accuracy.

Almost. You can chamber .223 ammunition in a rifle designated as 5.56, but not the other way around.

A rifle chambered in .223 will only chamber .223 ammo.

A rifle chambered in 5.56mm will chamber 5.56mm or .223 ammo.

Kind of like the .357 mag / .38 special setup.....