Building an AR 15 questions...

**Boker** · 09-23-2009, 07:48 PM

I've decided to look into an AR 15. Main purpose is for recreation. I won't need a gun that shoots 1/2 mile or that is decked out in the latest gear or name brand just for the purpose of the name. From what I can tell its significantly cheaper to build it yourself from kits.

Lower receivers are the registered item. Are there major differences in brands? I've noticed a huge price swing from $105 to $+200. If I want several uppers in different calibers, will any lower receiver work? Anyone have experiences in 7.62 x 39 AR 15s. I'd like to keep all my toys the same caliber. I've read that accuracy diminishes with the 7.62 rounds after 300 meters.

I'm still in the early stages of my research. With all the parts that seem to be on back order or just out of stock, I've got time.

**glockcop** · 09-24-2009, 10:27 AM

Some Colt and Military lowers have larger forward "hinge" holes in the uppers and larger ''hinge'' pins in the lowers, so be mindful of that. Pretty much all other brands have the smaller size. You can buy an in expensive pin sleave to take up the slack should you find yourself in that situation but not really a big deal either way. Get a forged reciever rather than the less expensive cast receiver due to stregnth and cracks that may develope. I also prefere a "flat top" receiver due to it's greater versatility with optics. Back up iron sights are also a great idea to have mounted on an optic equiped AR. Also get a 1 in 9'' turn barrel because IMO that rifling pitch gives the broadest range of bullets weights that you weapon can shoot. 1 in 12'' rifling pitch is only good for extremely light weight bullets. 1 in 7'' is only intended for heavy weight bullets. Barrel length is purely personal. I prefer 16'' due to the tight quarters mine gets used in (police work and hunting). You may want a 20'' barrel for more velocity. 18'' barrels are a good compromise for portability and velocity. Chrome lined barrels last longer but are slightly less accurate than none lined. I prefere the chrome lined due to greater life span of the barrel. The accuracy loss in a chrome lined barrel is so minimal as to be insignificant unless you are a world class comp shooter. Personally I prefere a gas tube over a piston operated weapon. The piston is just more parts to go wrong and break. Keeps your weapon clean between trips (which you should do anyway) and a gas tube is just fine. Besides when you start to "upgrade" a weapon with after market designs things can start to go bad. Piston driven weapons are more ammo sensitive and most are equiped with a gas adjustment on the front of the gas block to compensate for this. Gas tube weapons don't have this adjustment because it is not needed. The AR was originally designed with a gas tube not a piston and should be kept that way IMO. Stocks are also a highly personal subject. I prefere the six position retractable stocks due to their greater verasatility in tight quarters and varying thickness of outer wear. .223 is IMO the way to go in an AR. 7.62 is cheaper but does not have the range and trajectory that I need for a good tactical weapon or coyote popper. Your needs may vary. Any 223 length ammo will work with a reciever designed for .223. So yes, your .223 lower will work with other caliber uppers as long as they are the overall legnth as .223 ammo. Mags will be different also. Hope this helps. Best.

**Boker** · 09-24-2009, 02:56 PM

Thank you sir. That shortens up my research quite a bit.

**glockcop** · 09-24-2009, 03:10 PM

Glad to help. Good luck with your build. One other thing. Make sure your .223 upper has M4 feed ramps. These feed ramps are cut at 52 degrees rather than 45 degrees and allow for far less jams with high velocity ammo. You can identify this type easily. Here is how. Look at the rear of the chamber. The two small indentions at the 5 and 7 o'clock positions are the feed ramps. M4 feed ramps actually extend below the barrel steel itself. You will be able to see a "seam" about 1/3 the way up the feed ramp. No seam means not m4 ramps. It is that simple. Best.

**SARKY** · 09-24-2009, 08:40 PM

I'm in the midst of my build right now. I've got a forged lower that I built up with a match trigger, ergo grip and magpul trigger guard. I'm looking at 2 uppers. one in .223 the other in 6.5Grendel. The Grendel spans the gap between the .223 and .308 (being closer to the .308 in energy and trajectory all the way out to 1,000 meters) Plus I can make brass from 7.62x39 brass. The .223 upper i'm looking at is the new Para Ordnance.

**glockcop** · 09-24-2009, 08:58 PM

Sounds cool Sarky. Let us know how it goes. Best

**SARKY** · 09-24-2009, 10:43 PM

One other thing, as far as a military round/platform goes, the 2 things I disliked the most about the AR system was the gas impingment and that varmint round. After handling the AK I much prefered the thump of the 7.62x39 to the .223 and the fact that it was a just plain cleaner shooting gun. The fact that the uppers i am looking at are both piston driven solve the one problem and the 6.5Grendel puts the .223, 6.8SPC, and the 7.62x39 to shame, solves the other. Hell the 6.5 actually starts to catch up to the .308 (energy wise) when you start getting close to 1,000 meters.

**Boker** · 09-24-2009, 11:24 PM

Either of you mind if I PM you a link for opinions on a lower receiver? I don't want rick to think I'm advertising or anything like that;.

**crashdive123** · 09-24-2009, 11:28 PM

Boker - unless you are selling them from that link, or it's your website - it is OK to post it.

**glockcop** · 09-24-2009, 11:53 PM

Originally Posted by SARKY

One other thing, as far as a military round/platform goes, the 2 things I disliked the most about the AR system was the gas impingment and that varmint round. After handling the AK I much prefered the thump of the 7.62x39 to the .223 and the fact that it was a just plain cleaner shooting gun. The fact that the uppers i am looking at are both piston driven solve the one problem and the 6.5Grendel puts the .223, 6.8SPC, and the 7.62x39 to shame, solves the other. Hell the 6.5 actually starts to catch up to the .308 (energy wise) when you start getting close to 1,000 meters.

Sarky, come on man. The 6.5 is not, nor ever will be a .308 and I just don't have a thousand meters to waite for it to try and catch up. It's a respectable round but a .308 it is not. It does not need to be validated with comparisons to the .308. It is a fine round without such "attention grabbing". We have also debated this before: the gas tube system is much less complex than a piston system which means less crap to break and have to replace due to wear and tear. IMO a piston system is a "problem" that needs to be reversed into it's original form aka "A tube system". Who cares if your gun gets more dirty with a gas tube, you're gonna clean it at the end of the day anyway, right? Also typically piston rifles are more expensive. I can't justify the extra cost for a gun that has more sh*t to break on it. IMO AR's were designed with a gas tube and should be kept as such. Some say it is a technilogical upgrade. I say "HYPE". Clean it and it will be good to you. Also, no offense, but comparing an AK to an AR is laughable at best and is like comparing a Ford Pinto to a Cadillac. Not even close in quality, performance (accuracy/shootablity), ergonomics, fit, and finish. We are definately on different pages about this one, Brother. Stay safe.

**glockcop** · 09-25-2009, 12:03 AM

Originally Posted by Boker

Either of you mind if I PM you a link for opinions on a lower receiver? I don't want rick to think I'm advertising or anything like that;.

Boker I do not mind and would be glad to assist you in any way.

**SARKY** · 09-25-2009, 12:14 AM

GC, You got it wrong, I was comparing rounds, the .223 to the 7.62x39 and the actions, not the total platform. Ergonomically the AR is light years ahead of the AK. But i will tell you this, we never had an Ak go down for any reason. I can't say the same for our M-16s. But answer me this, have you ever fired an M-1 Carbine? Have you broken one down to clean it? If you have then tell me why isn't there a short stroke piston mounted on the barrel nut with a gas tube going to it??? The benefits of both piston and gas impingment all in one! Put 1,000 rounds through an AR and an M1 carbine and see which one starts having problems first. As to the 6.5 I was simply looking at ballistics charts and these are facts. I'm not saying the 6.5 is a .308, but then a .308 won't fit in an AR-15 platform. It's very much like the difference between the .44mag and the .41mag. I love my .41mag and it will do 90% of what a .44mag will do and do it shooting flatter. It's a matter of preference due to experiences.

**glockcop** · 09-25-2009, 12:33 AM

Originally Posted by SARKY

GC, You got it wrong, I was comparing rounds, the .223 to the 7.62x39 and the actions, not the total platform. Ergonomically the AR is light years ahead of the AK. But i will tell you this, we never had an Ak go down for any reason. I can't say the same for our M-16s. But answer me this, have you ever fired an M-1 Carbine? Have you broken one down to clean it? If you have then tell me why isn't there a short stroke piston mounted on the barrel nut with a gas tube going to it??? The benefits of both piston and gas impingment all in one! Put 1,000 rounds through an AR and an M1 carbine and see which one starts having problems first. As to the 6.5 I was simply looking at ballistics charts and these are facts. I'm not saying the 6.5 is a .308, but then a .308 won't fit in an AR-15 platform. It's very much like the difference between the .44mag and the .41mag. I love my .41mag and it will do 90% of what a .44mag will do and do it shooting flatter. It's a matter of preference due to experiences.

I gotcha. not a comparison of the platforms. Thank God. I was gonna send in the "guys in white coats" for ya

. I do agree that the m1 is a finely crafted weapon. As far as the 1000 round thing goes, I think anybody in nearly any situation would be cleaning their AR's before this arbitrary 1000 round mark. I have had mine go longer than that w/o problems in SWAT training and in the Instructor Academy. I haven't gone that long regularly but enough times to have faith in this weapon system. They were thrown into the bottom of a water filled dirt birm ditch and then "cleaned" with a garden hose afterward. This makes challenges to it's performance irrelavent IMO. They work alot better than some folks give them credit for. It is truely a reliable combat platform. I think you will appreciate my next adventure in arms. I plan to buy a Rock River Arms AR in .308. All the cheap FAL mags I can stand commin my way. Woooohoooo! I almost can't waite. Stay Safe.

**Boker** · 09-25-2009, 12:34 AM

http://www.wideners.com/itemdetail.c...13&dir=700|863

How do those look?

**glockcop** · 09-25-2009, 12:50 AM

Originally Posted by Boker

http://www.wideners.com/itemdetail.c...13&dir=700|863

How do those look?

I think I would spend the extra $$ for a higher quality one. On receivers such as these you may find a sizeable gap between upper and lower receiver when assembled. The finishing of the aluminum before anodizing is also probably gonna be uneven. I'm sure you can get all your parts in there and make it work but cosmetics may be an issue. One good thing is that it is forged. For the price I guess it may be worth a try. You won't be out much if it turns out to be a total bomb. That will be a cheap lesson learned. I have not used this particular lower but I do know what to expect from one in this price range. Probably fully functional but NOT pretty. Sometimes the cheapies also have problems with the mag well specs and the mags fitting in them. "You get what you pay for" comes to my mind. Good luck.

**Boker** · 09-25-2009, 08:33 AM

Originally Posted by glockcop

I think I would spend the extra $$ for a higher quality one. On receivers such as these you may find a sizeable gap between upper and lower receiver when assembled. The finishing of the aluminum before anodizing is also probably gonna be uneven. I'm sure you can get all your parts in there and make it work but cosmetics may be an issue. One good thing is that it is forged. For the price I guess it may be worth a try. You won't be out much if it turns out to be a total bomb. That will be a cheap lesson learned. I have not used this particular lower but I do know what to expect from one in this price range. Probably fully functional but NOT pretty. Sometimes the cheapies also have problems with the mag well specs and the mags fitting in them. "You get what you pay for" comes to my mind. Good luck.

I phrased that wrong. Not so much as the cosmetics, as will it function. This will be my first AR, so priority is functional #1. If I can build one for $600.00 or so I will be happy.

**glockcop** · 09-25-2009, 11:35 AM

Yeh, it will probably work just fine and if not I'm also sure that it can be rectified by a gunsmith. Hell give it a try and see. The thing sure is cheap enough just to try and it just very well may be fitted and finished nicely after all. Like I explained I have not used this particular receiver so I could be WAY off and the cosmetics and fit could be fine. IMO FOR THE PRICE and only for the price it is probably worth a shot. Let us know how this turns out. I am curious at this point. Best.