Removal of FSB with fixed hider?

[DB2]

Just received my CMMG M4 profile 14.5 upper (thumbs up AlohaRover!)and need to put my rail on. Hider is supposed to be soldered on. I don't want to heat it up to remove since it will destroy the finish. I am thinking, cut the sight base off completely. I'm changing the site anyway so I don't need it. Has anyone had to do this? How did you do without getting in to the barrel? I'm thinking cut through the rings on one side, score the other side and fold it open to remove.

Tips, or thoughts?

[ar15barrels]

What kind of gas block to you intend to install after the rail?

[DB2]

What kind of gas block to you intend to install after the rail?

YHM bolt on gas block with the flip up sight. Unless I find something else. The rail I have is a YHM full float. Smooth sides with rails out on the end. It has a slot for the post in the HG.


It should look some what like this when done.

[ar15barrels]

That's not going to be a fun job at all.

Awww, don't spoil his fun.
It's much more fun to hear people's after-action-reports on jobs like this.
It further justifies the idea of "paying a professional".

[PolishMike]

I had to do it on an upper i had where the FSB was rusted to the barrel and I couldn't get any of the pins out.

Get a dremel and cut both sides of both rings. You will not be able to just cut one side and bend it open. MAYBE if you score the other side, but you may as well just cut both.

Don't expect this to be fun.

[jdberger]

Awww, don't spoil his fun.
It's much more fun to hear people's after-action-reports on jobs like this.
It further justifies the idea of "paying a professional".

awww...c'mon. Half the work you professionals get is from us garage gunsmiths bubba'ing up our guns.

It's one better than getting the old "bag-o-parts".

[DB2]

I doubt that it can't be that much harder than what I go through on a daily basis.

I don't bubba.

[OSS]

I'm just wondering how you are going to get the other gas block on after you remove the fsb? Never mind I looked on yhm's site. Good luck.

[ar15barrels]

Half the work you professionals get is from us garage gunsmiths bubba'ing up our guns.

Perhaps 5% is "fix my mess" jobs.
They are always the most challenging.
Most jobs are machine work that can't be done without a lathe.

I had a crazy assembly job last weekend.
First, the build parts:
CMT receiver
Lothar Walther Stainless 14.5" M4 barrel
Samson 7" rail system
Knights Armament flip up-front sight
Knights Armament QD mount

You would not normally expect quality parts such as these to go together pretty easily right?

The Lothar Walther barrel measured 0.7514" at the gas block seat which is a full 0.0016" oversize.
The KAC front sight measured as small as 0.7485" ID which is a full 0.0015" undersized.
The barrel had to be machined down to 0.7484" in order for the KAC sight to fit.
The KAC sight has to get pinned to the barrel with taper pins and can ONLY be installed at KAC as it does not fit in a normal A2 front sight base drill jig.
A special clamping setup had to be done to clamp the sight square to the barreled receiver before drilling/pinning.

What would normally be less than a half hour assembly job with the permanent attach became a 3 hour nightmare.
Don't try this at home.

[Utha Schleigle]

Where do you guyz get the Bubbah 4lb hammer at. I have an interveiw at Stinkey's Rooter tomarrow and I have to show them any tools I have.

Have fun - but a man has gotz ta know his limitations.

[Roccobro]

awww...c'mon. Half the work you professionals get is from us garage gunsmiths bubba'ing up our guns.

It's one better than getting the old "bag-o-parts".

My LGS called it "box-O-gun". Sadly, I brought him at least one. A S&W 642 with a round count of zero I had dry fired (with snap-caps) and decided to clean out the metal shavings I was seeing through the FP hole...

Good luck on the Gas block! Maybe de-soldering the FH wouldn't be that hard or costly after all?

Justin

[ke6guj]

Good luck on the Gas block! Maybe de-soldering the FH wouldn't be that hard or costly after all?

Justin

might not be that hard to desolder, but could be very costly with that 14.5" upper becoming constructive possession of an SBR if the OP has possesion of a rifle lower and no legal pistol lower.

[Roccobro]

Break it down, and hide all the lowers in the whole city at an enemy's house out of state.

There, no CP to worry about.

Excellent point though! You always have great information Ke6guj.

Justin

[bwiese]

lmight not be that hard to desolder, but could be very costly with that 14.5" upper becoming constructive possession of an SBR if the OP has possesion of a rifle lower and no legal pistol lower.

CORRECT.

Yes, just saw this - I couldn't believe what I read! - the orig poster apparently wants to risk a felony to put a rail on (unless he owns no lower or owns a legit AR pistol).

These 14.5" people are gonna be the next round of ATF drama queen posters: "Help me, I need a lawyer".

[DB2]

Who's risking a felony? I said I DID NOT want to remove the hider, and for reference I DIDN'T. The gun is done and no felony was commited. My 14.5 upper is legal and you won't see a post from me asking help with legal fees.

I am not an idiot and I don't like you refering to me as I am one (you didn't say it directly). I'm sorry I even started this post, it was easier just to do it my self and shutup about it, rather than ask for ideas and get called Bubba and basically told to pay someone to do it.

I'm done.

CORRECT.

Yes, just saw this - I couldn't believe what I read! - the orig poster apparently wants to risk a felony to put a rail on (unless he owns no lower or owns a legit AR pistol).

These 14.5" people are gonna be the next round of ATF drama queen posters: "Help me, I need a lawyer".