AR Barrel Length Question

[turnerdye1]

well im trading my 16" carbine length upper for FN 20" upper. i have 2 questions..

1. what size handguard do i buy? is it rifle or midlength?
2. does anybody have any expierence with a FN upper?

 

[Shooter1]

Since I only see certain people with fn 20" uppers Its most likely a 20" govt profile 1/7 twist. You need any rifle length hand guard. The forward assist break easy with FN's, other than that it works fine.

 

[turnerdye1]

well ive never used the forward assist too much so im not too worried about that. if it breaks/broken ill fix it. so i take it they are pretty decent uppers?

 

[Shooter1]

I only see them since they are govt issue so they deff work....

 

[turnerdye1]

fantastic! thanks a lot

another question. whats a good rail? i am on a budget so i might just go with another magpul MOE because i have rails for it already

 

[Shooter1]

Snarf Snarf

 

[turnerdye1]

i pm'd you. i think im gonna go that option

 

[mkbar80]

To be clear, Carb/Mid/Rifle refers to the length of the gas system, not the barrel. Although I agree with Shooter that 20" probably means a rifle length gas system. I am a little confused with the statement below...are you refering to barrel whip? Are you suggesting a rail will eliminate this? Is this UTG rail a FF? Not sure how A2 A4 relates to PS's question unless your talking about rail height. Honestly just curious about what you're saying here.

For a 20 inch govt profile a metal two piece quadrail is better. Why? The 20" is very skinny and would whip alot without the reinforcement of a 2 piece qualrail. I personally tested a A2 against a A4. I believe for the money a utg is hard to beat, it locks up by 6 screws, and it is very solid. If you have over 100 get a nice YHM or something. A MOE rifle length with accessories would be lite but not sturdy and solid.

If accuracy is your desire, best case scenario is a free float system that puts No contact on the barrel at all. Larue and Daniel Defense would be the way to go if you can save the money. Troy/Viking Tactics makes some nice tubes for btwn 150-200. Look around and these can be had used in places. My own opinion would be to stay far away from the UTG stuff, the MOE guard will do all the same things with a few pieces of rail section from Magpul. I would highly recommend you go with the rilfe length MOE, until you have a chance to save some money or decide if you really need more.

Try skdtac, grtactical, bravocompanyusa for a starting point for shopping.

You can get the MOE rifle handguard and a two pieces of Magpul rail for $49.25 shipped. That will do you fine.

 

[Shooter1]

giggity giggity

 

[turnerdye1]

i kinda agree with what shooter is saying. this barrel is a little skinnier then others ive seen.

id be more then happy to listen to others opinions too

 

[j706]

To the OP if you are getting a FNA2 barrel or barreled upper it would behoove you to have the throat erosion checked before making a deal. There are many, many floating around out there that are gauging below service rifle specs....way below. The throats are shot out.

As to the post about the aluminum hand guards vs plastic for accuracy....ummmm..save your money because that dog won't hunt.

 

[turnerdye1]

throat checked? what do you mean? can it be seen from a picture?

its an A3 reciever not an A2. here are some pics


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[j706]

You need a throat erosion gauge. It is inserted into the chamber and measures the amount of throat wear. If the barrel is a used GI I would be concerned. If it is not I doubt it is worn. FN stuff will be chrome lined and takes a lot of rounds to wear. I know because I bought a FN A2 upper on here to build my son a rifle. Long story short I now have to buy another barrel. This one is 4.5 on throat erosion. They usually pitch them a 3.5 or so. FWIW there are VERY FEW FN barrels out there that are NOT used GI

 

[turnerdye1]

well i emailed the guy asking him where he got it from and asked for some details. i dont really wanna get this barrel and then find out its bad you know

 

[j706]

well i emailed the guy asking him where he got it from and asked for some details. i dont really wanna get this barrel and then find out its bad you know

Yea I hear you. Not saying that it is bad. You might be fine. If in doubt have someone check the throat out on it. If it is worn you will be able to tell once you start shooting it. It won't be unsafe just inaccurate.

 

[turnerdye1]

the guy said he put 50 rounds down it and had good groups at 100 yards. i could always just shoot it when it gets hear and find out for myself. if its not accurate i can just send it back

 

[j706]

the guy said he put 50 rounds down it and had good groups at 100 yards. i could always just shoot it when it gets hear and find out for myself. if its not accurate i can just send it back

There you go. Hope it is good. I wish I could find me a good used or new FN barrel myself. They make good stuff IMO

 

[j706]

By the way, as others have said that is a rifle length barrel and takes rifle handguards. Ebay is your friend for A2 handguards. I have bought more than one set for 10.00 shipped.

 

[turnerdye1]

well im just gonna have to go that route. hopefully its a good barrel. how can i check for bore erosion? is there a tool or what? how much does it cost?

if it ends up being a good barrel ill probably put a quad rail on it

 

[mkbar80]

W its a LONG skinny barrel and I think it would flex alot free floated.

A free floated tube allows for supporting the fore end without flexing the barrel. Something that would benefit a pencil barrel.

OP, I would still suggest an MOE until you see if there is something else you need/want.