2nd 5.56 barrel

[golfer]

I've recently received a 14.5" barreled Daniel Defense M4 and during discussion the question came up what it might take to add a 2nd longer barrel.
I really have no idea, can any of you help me with what I would need to add a 2nd barrel of say 18" to my rifle?
Thanks for helping.

[Rermey Lee]

I've recently received a 14.5" barreled Daniel Defense M4 and during discussion the question came up what it might take to add a 2nd longer barrel.
I really have no idea, can any of you help me with what I would need to add a 2nd barrel of say 18" to my rifle?
Thanks for helping.

You mean you want two barrels mounted on your rifle at the same time?

[P2000]

Your question is confusing.
Do you want to replace your 14.5'' barrel with an 18'' barrel?
Or do you want to own a second upper receiver with 18'' barrel, so that you can switch back and forth between 14.5'' and 18''?

[kerplode]

Perhaps buy another upper receiver assembly with the 18" barrel in a config you like? When you want to run the longer barrel, pop two pins, slap it on and go.

BCM has many good options...

[Travis B]

This to your existing lower.

36534

[golfer]

Please excuse my ignorance relative to the M4.
Obviously I can not have two barrels at the same time so that doesn't work.
I will try to rephrase and please forgive me if I blow it. Would it be as easy as mounting a different barrel into the existing upper assembly or would I need a complete upper assembly to have a 2nd barrel option.

[Clint]

Please excuse my ignorance relative to the M4.
Obviously I can not have two barrels at the same time so that doesn't work.
I will try to rephrase and please forgive me if I blow it. Would it be as easy as mounting a different barrel into the existing upper assembly or would I need a complete upper assembly to have a 2nd barrel option.

You can do either, depending on your goals.

Changing barrels is known as "re-barreling".

It takes some armorer skill to perform and is a semi-permanent change.

You will have a complete upper along with a leftover barrel.


Swapping complete uppers is super easy and takes 10 seconds.

You will have two complete uppers that can be swapped back and forth at any time.


With that said, what are your goals and why do you want a longer barrel?

[SomeOtherGuy]

What Clint said.

Generally, you replace the barrel itself on an upper when it has worn out, or if the specific barrel is completely useless to you for some reason. If the barrel is in good shape, but not what you prefer, it's often more cost effective to sell the upper and buy a new one with the barrel you prefer.

One of the major benefits of the AR15 design is the ease of swapping uppers and lowers, so many people will have more uppers than lowers, allowing you to quickly switch from say a 3-gun or defensive configuration to a longer distance precision setup.

[MegademiC]

If you explain what you want for capability, we could better direct you.

[golfer]

My last thread and attempt to answer did not go thru. I certainly appreciate your answers. It appears the only practical to have a two barrel setup would be to have a completely separate upper which could be changed out fairly quickly.
That answers my question very well.
Thanks and best wishes.