AR-15 lower receiver bullet variants

[SouthernSVT]

I have an AR-15 stripped lower that I'm getting ready to start building, but I already have a 5.56/.223 rifle built. Other than 5.56/.223 and .300 BLK are there any other variants that I could build with it? I would like this next rifle to be more of a long range gun than my current carbine that has no zoom on the scope.

My initial thought was a .308, but I would need to buy a .308 specific lower and I would rather just use the one I have. I know I can build a .300 BLK out of the standard lower, but I'm curious to know if there are any other options.

Bonus Question: Would a .300 BLK build be good for a long range rifle? They all use 16" barrels, which is what I have on my current rifle.

Any suggestions would be appreciated.

[Hmbre97]

How long is "long range"?

[YALE]

6.8SPC is probably your best bet, and another great alternative is a 6.5 Grendel. Either way, you'll be better off for long range the more barrel you have. I'd shoot for a 20" barrel minimum, but a 24" barrel would be more of a no-compromise deal.

[brandon01rt]

I have all the calibers mentioned in this thread, and 308 is by far my favorite. If you have to build on an AR 15 lower receiver, 6.8 spc is the way to go for distance.
The 6.8 has a unique bolt, barrel, and mag.

[SouthernSVT]

How long is "long range"?

The farther the better. I have a DPMS Carbine already that is set up with a 16" barrel, and an Aimpoint M4s scope. So it's more of a short/mid-range rifle. I want the second rifle to be as different as possible to keep it interesting.

6.8SPC is probably your best bet, and another great alternative is a 6.5 Grendel. Either way, you'll be better off for long range the more barrel you have. I'd shoot for a 20" barrel minimum, but a 24" barrel would be more of a no-compromise deal.

20"-24" was the length I was planning on, so that's right on target with what I've been thinking.

I have all the calibers mentioned in this thread, and 308 is by far my favorite. If you have to build on an AR 15 lower receiver, 6.8 spc is the way to go for distance.
The 6.8 has a unique bolt, barrel, and mag.

A .308 is what I really want, but with a lower sitting here it's very convenient to just use it. When all the AR-15 craziness started I was offered the chance to get the lower at normal store price, so I took it. I suppose I could look into a trade or sell it, but I only want the two AR's. After that I would prefer to start getting some of the other guns on my "to do" list.

I'll have to look into the 6.8 spc, and the 6.5 grendel. thanks for the input guys.

[Hmbre97]

You could flip your current lower and look for an AR-10 lower.

[YALE]

If you're trying to shoot, "as far as possible," hunt up a bolt gun. You can find a hot-rodded Remington 700 pretty easy for about half what they cost to build, if you're patient. Those guys build 'em, get bored, and move on to the new flavor of the month. You're likely to find them in something you'll be better off loading for, but to my mind, that's just a bonus.

[Trick Pony]

6.8SPC is probably your best bet, and another great alternative is a 6.5 Grendel. Either way, you'll be better off for long range the more barrel you have. I'd shoot for a 20" barrel minimum, but a 24" barrel would be more of a no-compromise deal.

6.8 SPC actually achieves full velocity in a 20" barrel. When going from a 16"-20" barrel, you will generally only see 75-125 FPS increase. Anything longer and you may actually lose velocity and you're just adding weight. Also, technically, a shorter barrel in the same profile can be more accurate as it is stiffer. If you ask me 6.8, is only good out to 600 yards, no different than 5.56.

6.5 Grendel is a much better choice if you're wanting to shoot long distances. In this caliber there are gains to be had in barrels over 20".

I am gathering the rest of the parts to build an LR-308, which definitely gives you much better options for long range. If you don't already have at least the lower for it, these days they are stupid expensive from private parties and out of stock at most dealers.

[Nash B.]

There are also .450 Bushmaster, .458 SOCOM, and .50 Beowulf if you want different, but they aren't really suited for long range.

[SouthernSVT]

I looked into the 6.8 spc and 6.5 grendel rounds a bit. From what I saw on the two, the 6.5 grendel is more what i'm looking for. Then I looked into some Remington 700's as recomended above, and i'm sold. I think i'm just going to sell my lower, and build a .30-06 700.

[black2002ls]

I looked into the 6.8 spc and 6.5 grendel rounds a bit. From what I saw on the two, the 6.5 grendel is more what i'm looking for. Then I looked into some Remington 700's as recomended above, and i'm sold. I think i'm just going to sell my lower, and build a .30-06 700.

how much for the lower?

[SouthernSVT]

how much for the lower?

I'm living in Montana at the moment, so it may be difficult to send it down to Texas. I don't really know how all that works to be honest. I would want to make sure I don't want it for something else before I sell it anyways. If I decide for sure I will PM you a price though.

[YALE]

May I suggest a .280-AI build, instead of .30-06?

[SouthernSVT]

May I suggest a .280-AI build, instead of .30-06?

I'll look into that. There were some types (including that one I believe) that I didn't recognize as bullets i'm familiar with. My first instinct was to go with .30-06 because it is something i'm very familiar with, and always easy to find. My Dad has a .30-06 which was always one of my favorite guns of his, and we have the ability to re-pack the ammo. It is also something common that would be rather easy to find around if needed. I'm always open to suggestions though. I know enough to get by in the firearms world, but I also know that there are some people on here who could run circles around what I know.

[SouthernSVT]

These TAC-21 Remington 700 builds give me wood...