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E.W.
09-03-13, 16:19
I could use a little help on a situation I have. I just recently purchased a BCM upper 14.5" barrel with the A2 flash hider. Along the way my plans changed and I decided to match this upper to a non SBR lower. I took the upper to my local smith and had the flash hider pinned, but now I'm 2nd guessing if the A2 is long enough to bring me to 16". What would be the most accurate way to get a barrel measurement on a fully assembled upper? I ran a guide rod down the barrel on a closed bolt and it came back so close to 16" that it could be open to interpretation. How would you guy measure to be sure? Thanks for the help.
Dead Man
09-03-13, 16:29
If it's a true 14.5" barrel, and you used a true A2 muzzle device, then the barrel is not a legal 16". I'm surprised your smith didn't catch that for you.

ATF measures the length from the face of the bolt to the end of the last piece of permanently attached barrel. So drop a cleaning rod down onto a closed bolt and measure to the end of the flash hider.
MSW
09-03-13, 18:38
One of my builds was like this--just a hair over 16.0" so I purchased one of the crush rings that added enough so there was no "interpretation" room. I then drilled, pinned & welded it, so ATF couldn't dispute things.

I got the crush washer from Brownell's.

Hope this idea helps.
Ryno12
09-03-13, 19:20
If it's a true 14.5" barrel, and you used a true A2 muzzle device, then the barrel is not a legal 16". I'm surprised your smith didn't catch that for you.

ATF measures the length from the face of the bolt to the end of the last piece of permanently attached barrel. So drop a cleaning rod down onto a closed bolt and measure to the end of the flash hider.

Many of them vary in length over the 14.5" so it's quite possible to be close if not over 16" OAL. It's been discussed here already in other threads. Also sounds like he measured correctly.
OP, I'm assuming there's a crush washer already installed? I suppose if you're that close & you're still worried about it, you could add a shim.

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nml
09-03-13, 19:30
Must be at least 16"

Measure dowel rod from the bolt face. If not 16" I would notify smith... Maybe purchase new muzzle device from him and he will remove and pin new one since you already paid for it
E.W.
09-03-13, 19:32
Thanks for the feedback. Live and learn.
jaxman7
09-04-13, 18:16
Measure it and let us know. I have a 14.7" BCM barrel w/a Battlecomp 2.0. It is shimmed yet still is over 16".

-Jax
E.W.
09-04-13, 20:47
Measure it and let us know. I have a 14.7" BCM barrel w/a Battlecomp 2.0. It is shimmed yet still is over 16".

-Jax

Well, I made an assumption on the measurement from the get go (admitatedly a mistake). I purchased the BCM upper as 14.5" with an A2 FH. BCM doesn't sell that configuration with the FH pinned so I figured that was were there NFA only came into play. I never measured anything before taking to my smith for pinning. I was reading on the web the other day that my config was going to be short, so I finally measured and it falls right on 16". I talked to BCM and they said i'm good to go with the configuration I have but damn, its a little to close for my comfort. How accurate can a made in China tape measure be.
Dead Man
09-04-13, 21:10
If it truly is NO LESS than 16, you're legal.

Ask how many people here have ever had their barrel length measured, though. I seriously doubt you'll be challenged.
Ryno12
09-04-13, 21:29
How accurate can a made in China tape measure be.

In 16"? Maybe +/-0.125. Maybe more.

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E.W.
09-05-13, 06:59
Thanks for the discussion everyone. I will have my smith measure it for a 2nd opinion and if he comes back with 16" as I have, then case closed.