I just bought a Stag Model 3 upper, which has a 4140 barrel with 1-9 twist and chrome lining.  Specs aren't up to my PSA premium or CHF FN barrels, but I got a great deal on it to complete yet another AR build that I didn't really need.

Anyway, I shoot 55 grain FMJ ammo 99% of the time, so I think 1-9 is just fine.  Being a semi-auto, I think 4140 is no problem, either.  Chrome lining is a bonus.

What say Arfcom?  Anything wrong with that barrel?  It comes with a lifetime guarantee, as if I would ever shoot it enough to wear it out, anyway.  

I just couldn't pass on the nice Diamondhead rail and flip up sights that came with this upper.  I love the feel of that rail.  I also didn't want to fork over another 85 bucks for the plus package if the standard barrel is good enough for my needs.

For the average person that barrel will be more than enough.

This^^

Only if you want to be the best operating operator ever to operate!

It isn't up to the latest mallninja specs! To few cheeto dust particles and pixie dust farts per inch. How do you expect to save the mayor's nephew with such sub-par equipment!

You must send it to me for proper disposal.










I am kidding. The barrel is perfectly fine. Barrels have been made from that steel for years and will probably be made from it for years to come. The thing now is 4150 steel, but the 4140 will do you just fine.

Now go out and blast a couple mags for geko.

Inb4:

"We won 2 world wars with 4140 barrels."

I have a RRA with a 1:9 twist chrome lined 4140 barrel and it shoots great.  If you got a good deal, shoot it and enjoy.  If prices are equal, and the only difference is 4140 or 4150/CMV then I would choose 4150/CMV.

OP...you done good.


I have 10 AR's.  The second most accurate rifle I own sports a 1:9" barrel made from 4140 steel.

There is nothing wrong with 4140 and most of the rack grade rifles for sale in stores usually use this type of steel. It has been an industry standard seemingly forever. I personally prefer stainless steel barrels and only use chrome lined or rack grade barrels for blasting away. They get rode hard and put up wet. If and when they go south on me I'll upgrade to a SS model when I replace it.

For the record I own a 1981 AR-15 SP1 with a 1/12 twist original barrel that I have done mag dumps, hip shooting and other high volume grin worthy events and it still shoots around 1.5 to 2.0 groups at 100 yards with match grade ammo. I have never worn a barrel out to the point where it keyholes. I do clean them after every outing, even if I only shoot a few rounds through the tube. It will at least get several patches down the bore and the chamber cleaned.

Take care of your equipment and it will last a very long time.

I have a gun show 4140, non CL barrel that has seen thousands of rounds of FA fire. No keyholing and it stays on a standard NRA rifle target at 100 yards. I doubt you'll have a problem.

The difference between modern 4140 and 4150 steel is not the same as it used to be with the main difference between the steel being the 4150 has more Carbon(C).  The life difference between the two steel you probably could not actually draw a difference.  Non-CL or non-nitrided metal will wear faster of both types of steel but if they are CL or nitrided they will both have great life.
One advantage I will note is that 4150 steel can withstand slightly higher temps but if you are not doing lots of FA or bump fire this will not be a concern.

LMAO! 

I've a Stag 2H with 4140 CL barrel. It has hundreds of rounds down-range with zero malfs, and shoots 2~3 MOA with typical M193 stuff (and a little better with handloads). I'd not hesitate to take it into the fray, should the need arise. You shouldn't, either.

Thanks, everyone! I thought it would be fine, but didn't realize how close it really is.  I'm looking forward to shooting it!  I'll post pics when I complete the build.

Most of my barrels are 4140 and have done a lot of FA fire and are still shooting great. My YHM-47-TF will give still me under 1moa with Fiocchi 77gr. They are both very durable. I've got 4150's and notice no difference or problems so I could go either way and you are GTG.

I put the Stag Model 3 upper on a PSA lower I just put together, with a gray BCM Mod 3 grip and MFT Minimalist stock.  Unfortunately, the grays on the grip and stock don't match.  Oh well, I don't care, because I like the way they feel.  I can't wait to get it out to the range.  Maybe tomorrow.  I also attached a pic of the Diamondhead rail.  It isn't very light, but it looks thick and strong and I love the feel of it.  The sights are really nice, too.  Thanks again for the input on the 4140 barrel.  It appears to be a heavy barrel, so that's a bonus.  This gun will eventually get a Vortex UH-1, or possibly a low magnification scope.

Lol. I'm going to have to hold on to that one for a rainy day.

The sad thing is that your joke is a dead serious reply from some members around the forums. But, I guess that's what makes your comment amusing.

Barretts  .50 barrels are 4140. That 5.56 barrel will be just fine.

I have that exact spec upper too.  Bought it probably 10 years ago.  It's been great, no issues.  I passed it on to my son when he asked about it.

First thing my 13 year old son said when he saw it and handled it was, "Is it mine?"  Lol!  Maybe one day...