Barrel movement?

[cazelle24]

I recently built my M4 and needed to know if there should be any barrel movement? It's a 16"in carbine length barrel with a YHM diamond series rifle length free-float rail system.

[ra2bach]

:eek:

[wahoo95]

Im assuming you are holding the handguard and bending the barrel?

[Zane1844]

Is the handguard becoming off center making the barrel appear to move?

Did you torque the barrel nut to spec?

No the barrel should NOT move.

[SWThomas]

Short answer. NO! The barrel should not move.

[polymorpheous]

Home build.
Doesn't know if the barrel should move.

Anyone else see what wrong here?

Short answer to the OP:
No.

Note to new members and AR owners:
If you don't understand how the rifle operates, and how parts work with each other to make a functional rifle, you probably shouldn't be building one.

[Red falcon]

O.o

That's definitely not supposed to move.. the barrel shouldn't flex either since you're using a freefloat rail system.

[wilco423]

O.o

That's definitely not supposed to move.. the barrel shouldn't flex either since you're using a freefloat rail system.

Barrels do flex, some more than others due to profile and material used. I'm guessing the OP means he can deflect the barrel in relation to the FF tube. As long as it returns to exactly where it started and doesn't have any free play, it's probably fine - ASSUMING the barrel is installed right and the barrel nut is torqued properly.

Agreed with those above that if the OP doesn't already know the answer, he shouldn't be building rifles yet.

[AKDoug]

I can take the barrel and the MFR tube on my DDM4V7 and flex the two towards each other just using thumb and index finger strength. It springs right back. I have no clue if the barrel or the tube is flexing, but it's not loose.

[polymorpheous]

I can take the barrel and the MFR tube on my DDM4V7 and flex the two towards each other just using thumb and index finger strength. It springs right back. I have no clue if the barrel or the tube is flexing, but it's not loose.

I'd imagine its the tube.

[wilco423]

I can take the barrel and the MFR tube on my DDM4V7 and flex the two towards each other just using thumb and index finger strength. It springs right back. I have no clue if the barrel or the tube is flexing, but it's not loose.

Aluminum tubes are really stiff - think of an aluminum bicycle frame, which are much stiffer than steel, titanium and most carbon fiber ones. I'm clearly no metallurgist or engineer, but I'd be really surprised if it wasn't only the barrel flexing. It's pretty easy for me to flex/deflect the barrel on my MK18 LW. The primary reason FF tubes/rails exist is to eliminate the flexing/deflection of the barrel when force is imparted on the forend.

[AKDoug]

I wasn't really clear in my post. It was to inform the original poster that perceived movement may not be a big issue at all. My rifle never gives me any accuracy issues.

[Ryno12]

I recently built my M4 and needed to know if there should be any barrel movement?

Seriously?

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[cazelle24]

Im not new to AR's, ive read in other posts that some barrels flex and thats normal. I came here to recieve infomation not a lecture.
Thanks to all who wasnt a jerk.

[polymorpheous]

Barrel flex or movement?
What exactly do you mean by movement?
You left a lot to interpretation.
Perhaps you should articulate you question in a way that is can be answered.
What is you experience with AR's?
Seems to me that some one with extensive experience assembling uppers wouldn have to ask a question like this.

[wahoo95]

Based on the description it sounds normal.

[steyrman13]

Im not new to AR's, ive read in other posts that some barrels flex and thats normal. I came here to recieve infomation not a lecture.
Thanks to all who wasnt a jerk.

From your original post it makes you sound as though you are new to them. More so on the building them side. Most werent trying to be jerks as much as confused as to why you would ask this? If you werent new to them. Also as stated it is not a great idea to be configuring or building them if you dont have experience. This could be a loss of life or limb issue if done wrong or poorly.

[HelloLarry]

If you can twist the barrel, you have a problem. In that case, the alignment pin slot in the upper is enlarged.

[markm]

I can take the barrel and the MFR tube on my DDM4V7 and flex the two towards each other just using thumb and index finger strength. It springs right back. I have no clue if the barrel or the tube is flexing, but it's not loose.

Yep. Barrels/receivers flex quite a bit. It might surprise you.

[AKDoug]

Doesn't surprise me at all. That's why we have free float tubes.