I just happened to notice, when looking at my PA "Black Friday" Radical Firearms midlength nitride barrel build, that the barrel spec engravings are at exactly top dead center. That's the preferred esthetic location for them. However, the engravings are ALSO nitride over. To my understanding... there is ZERO way to assure top dead center markings if engraved PRIOR to torqueing. Which means the entire, torqued B/E, barrel was submersed as complete (not separate as RF claims they switched to). Even if they loosened the B/E, submersed, then retorqued to spec... I suspect a 99% chance that the markings would NOT be TDC anymore.
So... I'm now 99% convinced that these barrels are part of the "nitride fiasco" that happened with RF. I haven't had any issues with mine (yet), but have also only assembled/worked on it once (to build).
So if I may... can those with these same barrels (PA "black Friday" RF nitride midlength barrel clearance sale) can please check their barrel spec engravings and report where they are located? I'm willing to bet they are ALL TDC. For those with these barrels... can you chime in please?

ETA: uh oh... just checked my PSA Ptac nitride middy too. I was always suspect that this was the same barrel (same profile, same finish, same EXACT engravings... in the same EXACT spot) and it, too, has them at TDC.

Oh don't tell me that, I have one that I was putting together as a budget build.

I have a Radical .308 BCG that has issues and one of these Black Friday barrels also waiting in the future builds box. Not a whole lot of confidence in Radical Firearms. In all honesty I bought
them through Primary Arms, ( a very respected vendor) otherwise I probably would have passed them up.

I am hopeful that any problems will be addressed and corrected, but with the falling prices of gun parts lately I find that  there are much better options available to throw my hard earned cash at.

I got the 16" SOCOM middy.

First and only range trip had poor accuracy and extraction issues.

Hurray......

I got rid of mine after two range trips. Accuracy akin to throwing rocks. Didn't give the barrel time to work loose.

Damn I bought one of those barrels for a cheap build. Haven't put it together yet, but now don't even want it. The only reason I bought it is because it was from PA, otherwise I would've never bought from a company with the word "radical" in its name...

I got a 10.5" on 11/17/2014. I'll take a look at the markings, but I haven't had any problems. I already planned on never swapping the muzzle device on it though, just in case.

I got one a few months back. Contacted Radical about installing an "A" style front sight since my local gunsmith says he won't touch Radical stuff.

Anyways, after several emails and a couple phone calls, never could I get someone to answer me if they could do it.

Barrel sits in my junk box. Faxon for me next time.

While I have only shoot mine 2 times, it has been adequate.  The accuracy had been good for a cheap $65 barrel.  But I am not extremely confident in the barrel because of all the issues that have been reported.  I may look into getting a different barrel for my build and never get a Radical again.

I've got one with 300 or so rounds through it. It's fine so far.  I've found a few kinds of cheap ammo that will shoot 1.75 to 2.5 moa. It does not like xm193 or Tula. I'm happy for $65. The more I shoot it, the better it seems to be getting. If the extension comes loose, I'll send it to Radical and see what they do. Either way, BFD.

My question was more of "where are your barrel spec engravings?". As that determines if your barrel was nitride post/prior B/E torque setting.
TDC= most definitely nitride POST assembly (bad).
Non TDC= perhaps torqued B/E AFTER nitride (good).

What if they engraved them after QPQing and put some black stuff in the marks?

My marks are darn close to centered on the gas port, black inside, and do not appear to have anything other than the nitriding to color them. I see what you're saying. It stands to reason that the barrels with centered, blackened engraving were assembled, engraved to match the index pin and gas port, and finally QPQed. At the same time, I've learned over time that "stands to reason" and "is" are two different things.

A little bit of Googling will show that various makers other than Radical have nitrided barrels with gas port centered, black engraving. Other makers have shiny engraving. Some makers' engraving encircles the barrel even. Your assumption that centered, blackened engraving always equals nitrided with the extension on might be flawed. If your assumption is correct, quite a few makers are nitriding after installing the extension. My guess is that your assumption is flawed.

From what I've read, if you nitride with the barrel assembled, it might stay tight or it might not.

At $65, I was taking a flier on this barrel just to see how a dirt cheap barrel compares to a good one. My lesson from the purchase was that whether cutting corners on a barrel makes sense depends on ammo prices. I don't really enjoy shooting rifles if they're shooting over 2.75 moa. A good barrel ($250-300) will put pretty much any ammo within that. If you have to pay an extra $.10-.25 per round or constantly be shopping around for just the right cheap ammo to make your gun fun to shoot, a cheap barrel might be a false economy. Right now, I'm getting ammo the Radical barrel likes for around an extra $.10 per round. At that price it makes sense. If the difference moves up to $.25, the cheap barrel becomes a false economy.

I checked last night and the engravings were on the TDC.  Everything seemed tight and good.  I have shoot many different types of ammo through it and a few hundred rounds, but I don't know how confident I feel about it.

I don't know, maybe you're right that they fill in the roll mark post nitride (sure doesn't look it, though). My PSA Freedom nitride also has TDC specs, but they are laser etched, which CAN be done post nitride (and that etching is not nitride looking, but actually yellow colored,). My Faxom nitride barrel was not roll marked, but rathe laser etched as well (white lettering).
So, I don't for sure... But I'm comfortable assuming a (nitride over) roll mark means nitride post assembly.

I am really not convinced that the nitride process is the actual cause of the loose extensions that have surfaced.  I am likely to lean towards shoddy assembly and not torquing to correct specifications to begin with, and it convinced me even more after seeing how their customer service team has attempted to repair barrel extensions when returned.

From www.northeastcoatings.com:

"The Melonite QPQ process is a multi step process that provides a very uniform consistent nitride layer on your components. The first step of the process is a preheat to raise the components surface temperature to about 700 - 800°F in air. The product is then transferred to the MEL 1/TF1 tank containing the liquid Melonite salt to begin the Nitrocarburizing process. The salt melt mainly consists of alkali cyanate and alkali carbonate. It is operated in a pot made from special material, and the pot is fitted with an aeration device. The active constituent in the MEL 1 / TF 1 bath is the alkali cyanate. The Nitrocarburizing process step is conducted in the MEL 1 / TF 1 bath at 896-1166°F, the standard temperature is usually 1076°F."

Those are higher temperatures than I would have guessed.

For what it's worth, I looked at three different nitrided barrels on Radical's website. All had black engravings centered with the gas block.

OP, I think a barrel maker could easily 1) drill the gas port; 2) engrave the barrel with engravings centered on the gas port; 3) put on a separately nitrided extension; and finally 4) install a nitrided index pin in the already installed extension that is centered with the gas port. Doing it this way gives you the advantage of nitriding the inside of the gas port too. I think you're assuming the gas port gets timed to the index pin. It could just as easily be the other way around. Maybe somebody on here knows for sure. If the index pin gets timed to the gas port, centered engravings wouldn't tell you anything about whether nitriding came before or after installation of the barrel extension.

Please don't give Radical Firearms anymore money.

I live in Houston where they are based out of. We see a lot of their stuff at local stores, gun shows and trade groups.

Here is my old thread:

http://www.ar15.com/forums/t_3_12/678751_Data_point___Radical_Firearms_barrel_untorqed_from_barrel_extension___Update__Bad_Customer_Service__.html

We have had 2 of their barrels untorque and 2 of their carriers have gas keys loosen. If you trust your rifle with your life, don't put a radical firearms part on it. It sickens me that they put this crap out.

I'm referring to the barrel extension, Not the gas port (which could be drilled out later). If the engravings are TDC, it means the barrel extension is already on (that's what determines the "top" of the barrel, until then, and the gas port, it is just a "blank"). As you probably know from barrel nuts... you cannot torque, loosen, and then torque again and get the same torque value in the same spot (you will go past prior position), thus my concern for the constant TDC engravings (which mean they are nitride post assembly, and either retorqued to a different value, or not at all).
Some may say that nitride has no effect on the torque values (when done as a complete assembly)... I'd have to disagree with that (given the heat range nitride puts the assembly though).

OP, you might be on to something here. I can't find anyone who sells a barrel extension without the hole for the index pin already drilled. I doubt many (if any) barrel makers machine their own extensions. Unless the maker fills the index pin hole and drills a new one, they have to drill the gas port after installing the barrel extension.

A lot of the nitrided barrels I see online appear to have nitrided engravings that are centered with the gas port and index pin. As far as I can figure, this opens a few possibilities:

1.A lot of barrel makers nitride after installing extensions, and LastRites is correct that installing the extension before nitriding is not the source of the problem;
2. Some barrel makers are plugging the index pin hole and drilling a new one timed to the gas port (if anyone can check for this, that would be cool);
3. There is a way to color the inside of the engravings black after the nitride has been applied that blends in with the nitride coloring; or
4. The engraving is not as deep as the nitriding (nitriding on 4140 seems to be able to go as deep as 1mm).

It's not just the index pin. Most extensions have m4 feed ramps that also have to be aligned

Castiel, that's a good point. It probably explains why the barrel extensions already have the index pin hole in them.