I have a post ban 14.5" Bushmaster flattop upper and I want to install the Yankee Hill "Specter" rail kit and permanently install a phantom in place of the AK brake.  The specter length rail kit is the one that covers the gas block and has a flip up front sight on the rail.  So far I have removed the brake with a dremel and cold chisel with absolutely no damage to the threads.   My question is this- can I simply dremel the front  sight down, leaving only the gas block portion (similar to Bushmaster's milled gas block) and leave the handguard cap on?  I know I have to remove the delta ring assembly and barrel nut, which leads me to the next question- can I grind off the delta ring and then use channellocks to remove the barrel nut (after removing the gas tube, of course)?  I don't have the upper vise block or the barrel nut wrench so I'm looking for alternitaves.  Thanks in advance for your help!

Dremel, cold chisel, channel locks - i nearly fell out of my chair.  You need a gunsmith before you break something that can't be fixed.  This is a hard job to do WITH THE RIGHT TOOLS, which apparently you don't have.

For starters, the FSB must be removed so that you can remove the old barrel nut and put the barrel nut for the Specter on your barrel, so you might as well Dremel that off too.  You need a special wrench to tighten the barrel nut on the Specter tube and you need a special wrench to tighten the locknut on the tube.

Don't mean to be rude, but IMHO you are in WAY over your head and need to seek professional assistance.

OK so I'm nuts.  Let's just assume someone who knows a thing or two removes everything properly, and then mills off the factory front sight base down to just the gas block.  Will the forearm fit over it then, or do I have to buy their low profile gas block?  That's the real question I'm getting at.  

YHM was advertising that they would install this kit for free but would charge only$35.00 if they had to remove the front welded and pined barrel attachment.

Contact them.

I believe a properly milled gas block will fit under the Specter tube.  

Did you get the Specter kit?  It comes with the proper gas block.

I just ordered the kit and yes, it does come with the specter gas block.  I guess I should have read the description more carefully before asking.  I did manage to strip the barrel all the way down with a dremel, pin punch, and 460 channellocks.  Man are those pins hard to knock out on the front sight base!!!  I completely destroyed the barrel nut but I don't think I need it any more.

I know we're guys and all, but when it comes to our babies, we should read the directions first

Per Yankee Hill's instructions in the back of their print catalog...

Do-it-yourselfers can just cut off the FSB, and WITHOUT HAVING TO REMOVE THE MUZZLE DEVICE, the barrel nut can be slipped off over the muzzle brake.  That's one big advantage to that 2-piece clamp on gas block...

I'm certainly not going to give you a hard time about what you did, because I'm impressed!  I like doing it all myself, and that's the one project I was TOO CHICKEN (or too big a' wimp ) to try.  Besides, it's JUST A BARREL!  If you COMPLETELY screw it up, it'll cost you $175 for a new one that you could try to put on yourself with a couple of c-clamps, some pixie sticks, and a tire iron

BUT to answer your actual question... The FSB CAN be dremel'ed down to fit under the float tube, but it has to be filed down farther than the Bushmaster "V-match" shaved FSB is.  It's been said here several times before that, without additional filing, the Bushmaster FSB will NOT fit under the tubes.

Glad to hear you got everything off ok, you don't know how easy it is to crack a reveiver when removing/installing barrel nuts without properly supporting the receiver.

You still have challenges ahead of you.  The YHM free float barrel nut requires a special wrench to tighten it and you also need some "ingenuity" to tighten the lock nut on the free float tube.

Let us know how it goes.

In order to avoid damage to the receiver, I held back on the barrel with a pipe wrench and stuck a screwdriver in the front sight base for additional support.  The wrench marred the barrel finish, but it's gonna be under the handguards anyway so who cares.   I'll post pics of the finished upper IF I can figure out how to post pics.  Wish me luck!

By the way I did order the special wrench for the new forearm.  $26

DAMN

You now qualify as a gunsmith in most Middle East Countries

Quoted: I have a post ban 14.5" Bushmaster flattop upper and I want to install the Yankee Hill "Specter" rail kit and permanently install a phantom in place of the AK brake.

You ARE mounting this on a LEGAL PREBAN, right?

Afterall, that phantom is a flashhider.

Maybe I'm mounting it to a single shot lower.  Maybe I'm gonna weld closed the gas tube hole.  Maybe I'm just building the upper as a paperweight and I don't own any lowers.  Fab10 maybe.  Maybe I'm just preparing for 9/14.  Why do you ask?

Just wouldn't want the naive to get in trouble.  

Good lookin' out.  No trouble here.

lu380:  You the man!

Quoted: Maybe I'm mounting it to a single shot lower.  Maybe I'm gonna weld closed the gas tube hole.  Maybe I'm just building the upper as a paperweight and I don't own any lowers.  Fab10 maybe.  Maybe I'm just preparing for 9/14.  Why do you ask?

Maybe fight4yourrights should change his screen name to: askpolitely4yourrights.

Let's not attack fight4yourrights.  It's just that in pointing out to people that they may be assembling uppers illegally or pointing out that "hey that lower in your picture is post ban because RRA never made prebans" might be dangerous.  Remember that this is a public forum and you might be giving ideas to one of the Billions of MMM members out there.

LU380 Please, Please and Please send your upper into me at YHM for installation "FREE". You pay shipping both ways. I would hate to see you gouge up a perfectly good firearm.
Call me toll free at 1-877-892-6533.
Paul Tetreault
Plant Manager
YHM

Now that's customer service!!  Looking out for their customer's best interests!!  Good job, Paul!!

Wow I heard you guys were good with customer service but this is above and beyond!  It appears you have talked some sense into me.  If you haven't already sent out the kit to me, I'd like to stop shipment and send my upper and barrel to you.   My order was placed on the fourth to the 19125 zip code and it was the xl specter forearm kit, along with the wrench and 3 panel covers. (just in case I don't get you on the phone in time).  I'll contact you tomorrow morning (5/6).  Thanks Paul!

Quoted: In order to avoid damage to the receiver, I held back on the barrel with a pipe wrench and stuck a screwdriver in the front sight base for additional support. The wrench marred the barrel finish, but it's gonna be under the handguards anyway so who cares.   I'll post pics of the finished upper IF I can figure out how to post pics.  Wish me luck!

Hey Boom, say what you want, but I'd rather put the torque stress on the barrel close to the nut than on the aluminum upper reciever, especially because I don't have the vise block.  Damage to the front sight base, delta ring, etc., doesn't matter because I won't be needing those parts anyway.  I will have to use the vise block to install the new forearm,  but for now while I'm waiting for it in the mail I just improvised a little.  I talked to Paul at YHM and the forearm kit was already shipped, so I think I'm gonna try to do this myself.  I can always send it to them for installation if I can't do it.  He even offered to refund the money for the wrench so that the shipping costs would be offset.  Great customer service!

Quoted: Maybe fight4yourrights should change his screen name to: askpolitely4yourrights.

People are free to make their own choices regarding the validity of certain laws, and their desire to comply with them.

I just didn't want to see someone doing it out of ignorance, which seems pretty prevelant today.  Lot's of folks buy illegal configurations and don't even know it.

Fighting the Man knowingly is one thing, by mistake is another.

thanks lu380

I was just busting your balls.  I'm sure you are only trying to help.

Well I didn't get Paul on the phone on time, and the kit showed up at my door today, Two days after I placed the order!  Thats fast shipping!  I assembled everything hand tight just to get an idea what's involved, and I am very happy with my purchase.  It kinda looks like a dissipator with the rifle length handguards on the M4 barrel.  I'm probably gonna send it back for installation tomorrow, just to be sure it's on nice and tight.  After that, all I need to complete the upper is the phantom, which is on its way from Del-ton.  I'm thinking about getting the C-more kit that comes with an A2 rear sight built into the mounting bracket.  Man this stuff is expensive!  Hey Fightforyourrights, where in PA do you live?  Do you know of any places to shoot that don't have the three round magazine rule?  I live in Philly (Fishtown section) and I go to the Nockamixon range once in a while.  One time I went and got a $90 ticket for loading more than three rounds in my pistol.  Just like all my parking tickes, I didn't pay and a month later three cars came to my apartment to arrest me! (At the time I lived in Conshohocken) Thank god I wasn't home.  So I broke down and paid the ticket and they left me alone.  Anyway, back to the subject of Rail forearms, I will definately buy from Yankee Hill again, great people to deal with.