AR questions...

[jsf343]

Hello,

I am new to this great site and am just starting to get into AR's and learning all the in's and out's. I have done a few searches on various things and the more I read the more questions and minor confussion my little pea brain has.

So, I was hoping to have a running discussion on AR's and different parts.

Thanks for any answers and replies you offer ahead of time I really appreciate it, it is one thing I really like about this site (people respect each other, take the time to answer questions etc.).

First question... what is the biggest difference in barrel length? if you were building an AR why buy a 16" verses a 14" etc. does length give a more stable/longer shot? shorter for closer shots maybe?

second question... what are some of the main differences in hand guards? I see hundreds of different types, is it purely looks or is there some degree of protection from heat? Do longer ones offer more stability wheen shooting? (being able to hold farther out)

Ok, that all for the moment, but there will be more.

[mike_556]

There are a lot of variables to your questions, perhaps a little more searching might help. One difference with <14" bbl's is NFA comes into play, is the difference worth the extra $200 stamp if you can own SBR's in your state? You'll see lots of differing opinions on bbl lengths and gas system lengths here. I run 16" myself on my POW's.
As far as HG's, are you looking to free-float or go with non-FF? That's one major difference. Heat shielding is something to be aware of (I'd avoid el cheapo chicom knockoffs). I like MOE HG's for non-FF applications myself.

[shua713]

I am still pretty new to the whole ar platform myself, this is definately one of the best places to get info. I have had some of the members of the forum come along side of me and help me with negotiating my way through the vast amounts of information on the subject.

[Hmac]

Hello,

I am new to this great site and am just starting to get into AR's and learning all the in's and out's. I have done a few searches on various things and the more I read the more questions and minor confussion my little pea brain has.

So, I was hoping to have a running discussion on AR's and different parts.

Thanks for any answers and replies you offer ahead of time I really appreciate it, it is one thing I really like about this site (people respect each other, take the time to answer questions etc.).

First question... what is the biggest difference in barrel length? if you were building an AR why buy a 16" verses a 14" etc. does length give a more stable/longer shot? shorter for closer shots maybe?

second question... what are some of the main differences in hand guards? I see hundreds of different types, is it purely looks or is there some degree of protection from heat? Do longer ones offer more stability wheen shooting? (being able to hold farther out)

Ok, that all for the moment, but there will be more.

Longer barrel gives higher muzzle velocity. Shorter than 16 inches is illegal unless an ATF transfer tax is paid and stamp obtained ($200, a significant paperwork hassle, and about a 4 month waiting period). A shorter barrel provides more maneuverability.

[rackham1]

First question... what is the biggest difference in barrel length? if you were building an AR why buy a 16" verses a 14" etc. does length give a more stable/longer shot? shorter for closer shots maybe?

I'm not the expert on this, but since your head is swimming here's a layperson reader's digest version:

As far as military use goes, another factor on barrel length is the fragmentation velocity of 5.56 ball ammo. Original 55 gr NATO ammo fragments in soft targets at around 2700 fps and up. Barrel length affects muzzle velocity, which affects the range where the bullet falls below fragmentation velocity. You can do some research and run ballistics to learn the differences between all the barrel lengths and their terminal effects.

I might have the velocity wrong, and it's OBE anyway (55 gr not issued anymore), but at least maybe it gives you a window into another factor.

Smarter people can correct or elaborate if needed.

[BCmJUnKie]

I think for every INCH you take off, you lose 25 FPS on velocity starting at a 20" barrel.

As far as handguards go, thats something I think is preference.

What do you plan on mounting, how long, FF or non-FF.

There are literally hundreds of handguards out there. The style in the past 2 years alone is quite different as far as what people use.

Check out the AR pic thread. You will get a really good idea of how people mount different things and how they use them.

[ra2bach]

Hello,

I am new to this great site and am just starting to get into AR's and learning all the in's and out's. I have done a few searches on various things and the more I read the more questions and minor confussion my little pea brain has.

So, I was hoping to have a running discussion on AR's and different parts.

Thanks for any answers and replies you offer ahead of time I really appreciate it, it is one thing I really like about this site (people respect each other, take the time to answer questions etc.).

First question... what is the biggest difference in barrel length? if you were building an AR why buy a 16" verses a 14" etc. does length give a more stable/longer shot? shorter for closer shots maybe?

second question... what are some of the main differences in hand guards? I see hundreds of different types, is it purely looks or is there some degree of protection from heat? Do longer ones offer more stability wheen shooting? (being able to hold farther out)

Ok, that all for the moment, but there will be more.

first AR? go with 16"... for all the right reasons...

second, rails are (or should) be needs driven - this means you should only add something, that you have determined through actual use, that you need.

other than sights, a magazine and ammo, the next thing an AR needs is a light and a way to mount it so you don't shoot people or things you don't intend to in the dark. you don't need a rail to do this.

I would honestly advise just getting the gun, half a dozen magazines, as much ammo as you can afford, and going out and shoot the gun. no one will think twice or criticize you for not having rails, fancy optics or doodads, etc., especially if you can operate the guns safely and reasonably well. if you have funds left over, try to get into at least a one day carbine training class. the words "you don't know what you don't know" are particularly applicable...

then, only invest in those options that you have found you need. rails are more or less personal choices and there are differences so take the time to ask "why" someone chose the gear they have. ignore answers like "it's the BEST!" unless they can quantify that answer.

good luck...

[jsf343]

can you next explain the differences between FF (free floating rail?) verses fixed? The fixed are more permenent correct? FF are easier on and off?

is there any difference other than those... maybe cost?

[Inuvik]

can you next explain the differences between FF (free floating rail?) verses fixed? The fixed are more permenent correct? FF are easier on and off?

is there any difference other than those... maybe cost?

Free floating handguards or rails do not touch the barrel. They attach near the reciever, and don't touch anything else on the gun (namely the barrel). The theory is that the barrel (and therefore accuracy) are not influenced by accessories or techniques which exert force on the handguard (and then barrel).

Regular (fixed?) handguards attach to the gun at both the reciever and front site base. Any force exerted on the handgards 'may' influence accuracy. They are generally less permanent and more easily changed FYI.

It is all about what you are trying to accomplish, and how much you want to spend.

[rackham1]

can you next explain the differences between FF (free floating rail?) verses fixed? The fixed are more permenent correct? FF are easier on and off?

is there any difference other than those... maybe cost?

Free float effectively "locks" the handguard to the receiver. Shortest answer is it allows better accuracy because no outside force is putting stress on the barrel during a shot.

When you say "fixed" I think you mean "not free floated", which would be any other handguard or rail that's clamped between the receiver and the front sight base. Since the handguard/rail is supported at the FSB by the barrel, it puts stress on the barrel during a shot.

FF are typically heavier duty and take a little more work to install. Some are easy and some really need someone that knows what he's doing. They also allow more advanced configurations of lights, grips, optics, slings, etc., because they're commonly used with low profile gas blocks which means you can get more room.

Non free float usually just slip right in and out, and of course are limited to the length available between the receiver and the FSB.

FF are spendy so a person should really need the accuracy, durability, and rail space gains to make it worth it. Your average person that doesn't compete or fight with their rifles might not really notice the difference.