My first AR15 build


October 12, 2008, 11:58 AM
I have just completed building an AR15 lower.....

I got a stripped Stag 15, 5.56 lower, added a lower parts kit with single stage trigger and collaspalbe butt stock.

Now i am looking for the upper. I anticipate using this for HD and plinking at 100 or 200yd max. I already have an extremely accurate .308, so this is more of a fun/HD gun.

I think i want to keep the overall barrel length to 16". What are your thoughts on mfgrs, twist rate, other options, sights, etc.? At some point in the future, i may switch to a two stage trigger.

Is it true that I can have multiple uppers with different calibers and just use the same lower?

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October 12, 2008, 12:22 PM
Here are two great links with tons of information.

This one is a buyers guide.

This one is information on building your rifle.

October 12, 2008, 12:24 PM
I have gotten good results and service here:

Prices are good too.

October 12, 2008, 12:56 PM
Yes, there are several calibers now commonly chambered for uppers, particularly 6.8 SPC, 6.5 Grendel, and .204 Ruger. If you get one to use for .22 LR, make sure you get one with the correct caliber barrel.

For rate of twist, this gets complicated, but most of the time, 1/9 works. If you plan on using really heavy bullets, you might want to consider 1/7. (Current military rifles use 1/7, but they use exclusively 62 grain bullets.)

Also pay attention, you don't want a .223 chamber, you want a 5.56 chamber. They are NOT the same thing. Most rifles/uppers will be chambered in 5.56.

October 12, 2008, 01:13 PM
Congrats, steverjo! You're gonna have fun when you get the upper installed.

The standard commercial twist is 1:9, which works for all bullet weights up to 62 grain. For plinking and self defense you'll use 55 grain, and 1:9 twist works great. Heavy bullets of 69 grains or more need a faster twist. That ammo is much more expensive, and is most useful at longer ranges and specialty shooting (like armor penetration, etc.). Get the 5.56 milspec chamber.

Standard commercial bore will work for 22 long rifle. I have tons of fun shooting 22lr. It converts with just a bolt carrier change, and magazine. Everything else works great.

Your lower will also work with all short alternate cartridges listed by mljdeckard (plus 9mm and 7.62x39), but to shoot long centerfire like .308 takes a whole different lower.

16" barrel works great out to about 300 yards. You don't really need a heavy barrel for those ranges, but many people get completely convinced that a heavy barrel will make them better shooters. For self defense, I would stick with a lighter contour.

Everything else is up to you. Get what you want, not what someone else wants for you.

October 12, 2008, 04:52 PM
The .22 LR will shoot with the regular bore, but not very accurately. The bore is .002" different. If you want it to be accurate all, you need a dedicated upper in the correct caliber.

October 12, 2008, 05:03 PM

October 12, 2008, 05:14 PM
I built one from a kit and it works fine, though the trigger was junk, I switched to an Armalite trigger group and got a big improvement in groups. I've had a couple of uppers on that unit and have changed stocks as well. In every case, it was more accurate than I was.

I see no advantage to barrels longer than 16" unless there is a particular objective for it, like headshots on prarie dogs at over 100 yds.

October 12, 2008, 06:13 PM
Here's my 16" barrel build.

October 12, 2008, 08:39 PM
Del-ton is great and coleman tyler usually has good prices on dpms and cmmg parts kits and uppers.

AR-15 Rep
October 12, 2008, 08:50 PM
true on the different uppers and same lower, but they are making lowers dedicated to calibre or marked multiple. Once you get the BRD you will probabley get more lowers.

October 12, 2008, 09:17 PM
Ranger sales looks strangely close to model 1 sales product wise. I've bought about 3 kits from m-aparts and have had decent luck, apart from a problem with an M4 receiver and a non-M4 barrel extension. I sold the rifle so no big deal for me, but I'm pretty sure they fixed the problem. I also bought a kit from del-ton and had pretty good luck for the most part. Jammed a bit when it was new but may have been improperly sized brass.

Basically, find an upper you like and put a BCM BCG in it.

Yes, you can put your AR15 lower on almost any AR15 upper, the only problem you will have will be different sized holes in the upper (which I know little about) and putting a non-sbr registered lower on a sub 16" barreled upper.

If you think you might want a scope on this rifle in the future, get a flat top and a detachable carry handle or a flip up. If you don't think you will want to put optics on this rifle, get iron sights. If you decide you want to put an EOTech or something of that nature on it, you can get a rail that screws into the carry handle, or even buy another upper.

If you enjoyed reading about "My first AR15 build" here in archive, you'll LOVE our community. Come join today for the full version!