So about 6 months ago I got a Radical Firearms 7.5 inch upper (don't remember who from, could have been Red Barn). It was a bit picky at first with a carbine buffer, but a ST-T2 buffer (and perhaps some bcg break-in time) made it run much better. The only draw back was the A2 birdcage. It was loud and had a lot of gas off to both sides. So I replaced it with a KX3 "pig" linear comp, which helped a lot. But after a few months I got sick of the weight of the KX3 and decided to go with a Kaw Valley comp. Well the other day my Kaw Valley comp comes in the mail. So I take the upper off and put it on the block setup (the kind mad so an AR upper can go into a vice without causing harm) to take the KX3 off. Well the Kx3 did not move, but the barrel itself instead came unscrewed from its collar and in the process twisted the gas tube half way around the barrel. Now the collar (the part with the notch that goes into the upper) is still in the upper and the barrel is loose. I tried to screw the barrel back onto the collar, but neither have any "flat" places (both round) to get a wrench onto (have no strap wrench). With a hand tighten the barrel is no longer timed correctly and the gas tube (had a spare cause the original twisted off) will no longer line up correctly. So now my Radical Firearms upper is junk-box-trash, all because I just wanted a different muzzle device. Between that and the badly out of spec rail, I don't think I will be getting any more uppers from Radical. I could just put on a new barrel, but the collar is not going to come out of the upper (without some heavy bigfoot or yeti brute force). So the upper itself becomes useless. Very bummed about this and I don't have much hope that if I contacted Radical about it that they would do much or anything. I'm not saying this will happen on all uppers from them, but there could be a chance.

Sir, I have no experience with Radical Firearms but... you need to get some proper tools, learn the correct names of the parts you are referencing, and learn how to correctly install a barrel. Your lack of specific AR knowledge mixed with your description how your problems came to fruition makes me think user error was a factor here. DannerTrax

The damage you caused was because you used the wrong tools. Why the rail may be their fault the rest is yours.

+1.

This doesn't sound like a manufacturer issue and certainly calling their product out here won't help you much.

If i were you i'd take some pics and contact whoever you bought the upper from or even Radical. My guess is their answer will be the same. You replaced the muzzle device twice and although you used a vice block i'm not sure exactly how you removed or installed them, it certainly doesn't seem to be in an approved way.

Good luck with your search

p.s. it sounds like your broke the barrel extension loose from the barrel itself. If so you must have applied some serious torque. What exactly were you trying to turn and using what?

+1
I'm wondering if the location pin is broken.

Bingo. Thats crazy shit... nevah been done befoe... I would guess.

I've heard more than one case of Radical Firearms barrels coming loose from the barrel extension.  Although you did use the wrong tool for installing muzzle devices, the extension should be torqued to 150 ft/lbs and should NOT come loose from unscrewing a muzzle device, unless it was tightened more than 150 ft/lbs.

Radical Firearms has admitted to meloniting the barrels with the extensions installed and then they claim to re-torque them afterwards, which doesn't seem to be working out very well for them (or they're forgetting to do it sometimes)

Contact them and they should replace or repair it.  Although when this happened to my friend they charged him $25 and they rocksetted the extension instead of replacing it

There are posts in the archives where someone was attempting to unscrew the muzzle device and didn't have the barrel itself secure.

The pin frequently rips out of the upper nose, or just falls out. It's not drilled into the threads, and is just tapped into place.

Remove the gas tube, unscrew the barrel nut threaded over the nose of the upper, and pull out the barrel assembly. Check to see if the pin is in the same alignment as the gas port. Once headspaced and pinned, then the port is drilled to match the vertical pin so the tube will go into the receiver. A half twist off and the headspace no longer exists correctly as the threads make it change length when turned.

Most barrel assemblies are shipped headspaced and the extension pinned with the gas port at vertical. It's the one thing that remains gunsmith level work on the AR - and it's still a lot easier than pressing a barrel into a receiver while getting the headspace at the same time.

There is a significant point to the subject in that the TM doesn't list a torque figure fpr the extension - because the armorer isn't authorized to do the work. Completed assemblies are the stock in trade so it's important to note that the TIM does specify how to hold the barrel properly for installing the flash hider because if you fail, the weapon is damaged.

Be careful that the torque figure mentioned in a lot of internet threads is based on one custom machinists explanation of how he custom fits each extension. IIRC it's been said that isn't how it's done when making thousands a week.

http://pdf.textfiles.com/manuals/MILITARY/Army%20M16A2%20and%20M4%20manual.pdf  for how to work on the M16. If it's too long a read to do it right, don't.

Replacing an extension is a giant hassle due to the timing issue with the gas port/TDC of the barrel, rocksetting it makes sense to me if you have the correct extension. Extensions are installed and then the ports are drilled is my understanding after having bought some barrels that were 100% assembled and then had their extensions removed. Hand tightening 200+ extensions to find 10 extensions that timed correctly.  Barrel index pins are just pressed into the extensions, they don't go into the barrel itself.

My point was more that radical definitely has some QC issues, and it seems that rocksetting and charging $25 is a pretty poor solution when they really should be replacing the barrels under warranty at no charge.

Ripe and full of fail, the reason why it unscrewed.  And you cannot re-torque afterwards as it's about 1 in 1000 chance of it lining back up correctly.

If you contact White Oak Armament they could put a new extension on for you for a minimum charge, ADCO might also offer this service.  You are not the first and won't be the last for this to happen.

Wow, the hate is strong in this thread



OP appears to have used an AR vice block and tried to remove his KX3 in the approved manner - or at least consistent with what Brownells advises:
http://bcove.me/jj6zrksk

I can't say how much torque he applied but given all the other comments about Radical having issues, it doesn't seem to me out of the realm of possibility that he did NOT overdo his removal attempt and instead the Radical barrel to extension connection was out of spec...

OP: I'd contact Radical first and see what they say - if you legitimately overtorqued it then expect to pay, but if not, I would expect a fix gratis myself.  It's not like changing flash hiders (sorry Mil-Spec bigots, "flash suppressor") is something that should be rocket-science and not to be attempted by a typical owner!

Just my $0.02,
Richard

Brownells can be wrong. You do not use a receiver block to remove a muzzle device. You use a barrel extension tool like the reaction rod or barrel vice blocks.

Bingo!  We have a winner.  Barrel vise pads are cheap off eBay.  Look for the nylon ones with a V-groove across the face.  They work like a champ, and there's no risk to your barrel pin.

That vid does not show or mention how upper was prepped in vice, may well be barrel extension tool in there, vid too low rez to tell.

- OS

Radical Firearms is getting a reputation for poor builds. I would spend a little extra and get quality workmanship.

Your barrel came loose from the barrel extension. Same thing happened to me. If you bought the upper new, call or email Radical as it's under warranty. They'll ask you who you bought it from and for an order number and they will just send you a new barrel.

I had mine fixed for $25 because I bought mine used. They lined up the barrel and extension index pin, rocksetted it in place, checked headspace and test fired it. It hasn't had any issues since getting it back. I'm happy with the response I got given I wasn't the first owner and how quickly they responded.

Also, someone mentioned breaking the index pin. You're not going to break the pin by breaking the barrel loose. The index pin is for indexing and isn't meant to help retain the barrel in place. It does contact the barrel threads but there is no hole or anything drilled into the barrel.

Well now that isn't way it is supposed to be done, not even close.  There is supposed to be 150ftlbs of torque and the above method is bullshit.

And now all these "fixed" AR's out there on public ranges. Makes me cringe at the thought!

Most people probably just get new barrels under warranty. I opted for this "fix" since they wouldn't replace the barrel as I was not the first owner. I wasn't too surprised though as it seems like most manufacturers don't warranty stuff not purchased though them or some authorized vendor. I was pretty disappointed at that, but didn't want to trash an otherwise good barrel.

You should have contacted the person you bought it from and had them send it in.

I tried to spin the muzzle device off to replace on my diamond back. The barrel moved so I reversed till I get the proper tools. The thing stills runs right so I guess I got lucky.
You shouldn't need to be an armorer the change out the flash hider.

This.

OP removed the oem fh, then installed the kx3.  How much torque did the op use to install the kx3?

I had to send back my upper to RF for some issues I found also. They fixed it for me though.

Oh I wouldn't be running that until it got properly checked and likely repaired needing a new extension.

A reaction rod still engages the locking lugs in the barrel extension, not the barrel itself.  It does prevent loading up the index pin against the aluminum receiver, but if the barrel extension isn't torqued to spec, the barrel will still spin with the muzzle device even with a reaction rod in place.  it sounds like that method would not have helped in the OP's case.  

Vice blocks are really the only way to grab onto the barrel itself, but it's not always easy.  Some handguards are a PITA to remove or have end caps that don't fit over the muzzle device, which can make it hard to get enough exposed barrel to sit in the vice.  

I've always thought it would be smart of barrel manufacturer's to mill some wrench flats onto the barrel itself, right behind the muzzle threads.  If that were common practice, we wouldn't have to worry about where to react the torque.