Has anyone installed one of these? Do you really have to remove the barrel? Can you just remove the sight tower instead?

If you remove the barrel does this mess with headspace? Does the barrel have to be timed or anything special? Or is it just wrench on till tight?

Thanks

i have NEVER seen one of these FF systems yet.  Only pictures, month after month in Shotgun News.  I don't know of anyone who has.  I would be courious to get info though.

I prepaid for mine in June or July - still no sight of it.  Every time I call ; "about 2 more weeks."

So, I can only try to answer part of your questions.
If you do remove the barrel from the upper receiver it should not mess with your headspacing.  Headspacing is a function of your barrel&extention matched up to your bolt.

Torque specs on reinstalling a barrel are somewhere between 30 - 90 ft/lbs. ... give or take a couple of ft/lbs.  It's not really that hi-tech, just tighten it to about 50ft/lbs and make sure a gas tube can fit through the slot on the barrel nut.

I am assuming the GGG install is something like the ARMS SIR (military model) install,  but as things are going I might never know?????????????
best of luck to you.

GG&G is a very strange outfit.  I remember in June, asking about the freefloat system and that I was considering ordering one in a few weeks.  He spent 10 minutes on the phone with the pressure sale tactic and in fact tried to insist that I pay for it right then as a sign of good faith.  It almost seemed like he needed the payment in order to make sure the product was actually going to be put into production (just my speculation).  Hearing the waiting time, it looks like I'm lucky I didn't order it.  I am curious about the reviews on the product when people do recieve them.

I feel the same way, and i don't understand????????

it is my understanding that the "first" batch went to fill US military orders qty-150plus?
As a prior service guy - that is very ok with me, espicially in these times.  
But as soon as the product was advertised on the cover of Shotgun News, I called for a price. They did not have one.  I called about every 5 days until I got a price, and I immediatly ordered a initial sample, pre paid via bank check.
I only ordered one at the time because most of my work is building and accessoriesing, advising for LE agencies.  I have M4 rifles with the SIR system, M4RAS, Samco 4 rail, and various FF tac tubes.  After seeing the GGG I began to promote the quality of the company and it products!!!!!!!!!!!!!, and before they mad a decision for their next batch (8-12 M4's before the end of Q3,2003 and the same Q4, 2003)
I admit I have alway been a big fan of their quality.
When I ordered it in summer i think i was told my order would be ready near the end of August.  Then "2more weeks", 2 more weeks", now at last contact it was ..... you guessed it "two more weeks"  That would put us at thanksgiving.  Along with that answer the customer service rep, also made a comment that his initial orders had been shipped some time ago. (comercial)(i still ask where was mine)

I am sure you can tell the bidding for the last requ. order has came and went. (I should have stuck to KMC, or an offbrand FRee FLoat.)  My sugesstions with all of its features and benifits has never comed to verision.
that account is lost.
i tried to get fancy, the other bidders, and decision makers for the job; knew and loved ARMS, they knew and loves KMC, and for the most part were no totally familur with GG&G.  This could have been a great opening; show them a product that meets and EXCEEDS all their needs, offeres more versatitity, and save them money (they LOVE THAT PART)!

CARPA DEE IM - spelled wrong

thanks