AR-15 Question... (many more to come)

[Uncle Giggles]

Why is it that all of the 16" barrel models are called "Carbines" and all of the 20" models are called "Rifles"??

Since there's a distinct chance that this question doesn't make much sense (since I'm an AR newbie who just caught The AR Fever BIG TIME), here's an example:

http://www.bushmaster.com/shopping/weapons/

It might also help if someone could define the word "carbine".

Sorry I'm such a helpless fella when it comes to AR's... my roommate just bought an AR-15 from Alexander Arms that fires the 6.5mm Grendel and after a few minutes of research on AR's, I was instantly addicted to the .223/5.56's. So I'm basically coming into the AR thing totally unprepared... all I know is that I want one and I need to do TONS of research to make my best selection.

Thanks in advance!

[MarineFlyboy]

The carbine is the little cousin of the M16. Its basically your M16 but is shorter and lighter which makes it better suited for close quarter combat. If you stick with the good brand names you can't go wrong with whatever you decide to get. Check out Bushmaster, Rock River Arms, Stag or LMT to start with. Welcome to the addiction!

[Uncle Giggles]

Originally Posted by MarineFlyboy

The carbine is the little cousin of the M16. Its basically your M16 but is shorter and lighter which makes it better suited for close quarter combat. If you stick with the good brand names you can't go wrong with whatever you decide to get. Check out Bushmaster, Rock River Arms, Stag or LMT to start with. Welcome to the addiction!

Thanks. I'd be more interested in a 20" or so barrel as opposed to a 16" just for accuracy's sake, but I've heard that the 16" is the best for a rifle you can stand and shoot with. Are the 20"+ barrels really that unbareable to shoot standing?

By the way, I must have researched 20+ AR manufacturers last night, and so far I really like Bushmaster. I'm thinking about either a 16" or 20", A3 Upper, and that's basically it. Just start with a very basic A3 rig and modify it to my liking as I go.

[nikon777]

What's ur primary purpose for the rifle. Is hunting etc then the 20inch would be in order. For fun and home defense the 16inch is still plenty accurate.

[SpringfieldXD.40]

Originally Posted by nikon777

What's ur primary purpose for the rifle. Is hunting etc then the 20inch would be in order. For fun and home defense the 16inch is still plenty accurate.

I agree- I think you will be pleased with the accuracy of a 16"

[Badshot]

http://en.wikipedia.org/wiki/Carbine

The 20" will be more accurate at long range. Other factors are twist rate, pressure points on the barrel (the less contact on the barrel the better hence the reason folks Freefloat their barrels), barrel type - Heavy, Fluted, Fluted Heavy, M4 cut, light and pencil light (the last two are typically found in the older A1 models but can be had on newer A3/4 models as well)

The general consensus is that 16" is more than fine for the majority of civilian applications. If you think you're going to want to shoot accurately beyond 300meters then consider the 20". If you're use will have you shooting at less than 300m then the 16" will more than meet the need.

Hopefully someone with better understanding can give you detail on twist rate recommendations.

Welcome to the addiction!

[DanTheEldest]

I'm hardly an expert (semi-informed noob might be more accurate), but I have done a little looking on twist rates for barrels as I've kicked around configuring a 24" varmint AR. Most .223 AR's will come with a 1 in 9" rate, which is a good compromise twist for general all-purpose use. It will stabilize your common 55-gr rounds nicely, but will also work for some heavier rounds (high 50-gr's and maybe low 60-gr's, I'm not sure), and some lighter ones (low 50-gr's).

Many folks who are using their AR's for service rifle competitions will go with something like a 1 in 8" or even a 1 in 7" because they use heavier loads (high 60-gr's and even some 70-gr's) to maintain accuracy at distance. The heavier bullets work well with the faster twist rate, but lighter rounds can over-spin and in some cases actually fly apart and disintegrate, or go way off-target.

If I was buying one just for fun/all-purpose shooting, I'd get a 1 in 9" or 1 in 8", leaving some options open for using slightly heavier rounds if I felt like it.

[Uncle Giggles]

Originally Posted by nikon777

What's ur primary purpose for the rifle.

Targets only. No hunting, and no self defense (that's what the .45 ACP is for )

Originally Posted by SpringfieldXD.40

I agree- I think you will be pleased with the accuracy of a 16"

That's good to hear. I may opt for the 16" after all.

Originally Posted by Badshot

If you're use will have you shooting at less than 300m then the 16" will more than meet the need.

I am certain that I will not need to shoot nearly that far with the rifle. I'll go for the 16".

Originally Posted by DanTheEldest

If I was buying one just for fun/all-purpose shooting, I'd get a 1 in 9" or 1 in 8", leaving some options open for using slightly heavier rounds if I felt like it.

Almost all of the Bushmasters I'm interested in have the 1 in 9" twist. What do you think would be the optimal weight bullet for that? Is 55 grain pretty much the standard for 5.56/.223's?

[hikeeba]

What sort of targets are you going to be shooting? Are you planning on competing with the weapon, or are you just planning on heading to the range now and then to sling lead at paper plates and such?

[DanTheEldest]

Originally Posted by Uncle Giggles

Almost all of the Bushmasters I'm interested in have the 1 in 9" twist. What do you think would be the optimal weight bullet for that? Is 55 grain pretty much the standard for 5.56/.223's?

Yeah, the 55-gr stuff is basically the standard round for us civvies for all-around shooting. I'm not entirely sure about this, but I believe with the 1 in 9 you could even get up to about a 62-gr for longer distances and a bit more power if you felt like it, but all the "cheap" factory ammo is 55 these days. If you handload, however, the sky's the limit.....