Barrel Opinions/Questions

[alamo5000]

I was able to stop by and handle a (for about 5 minutes) some SBRs yesterday...which has me thinking about my SBR build. I know it's been on the back burner for a while but it's still on the want list.

That said with the whole set of barrel choices out there what are the various opinions of chrome lined (aka RA Mountain Series type barrel) vs a Melonited or Nitrided barrel?

The idea for this one will be for hard use much more than pinpoint accuracy.

Given keep in mind that my idea of hard use isn't 'full auto' mainly because I can't afford that much ammo. [:D]

Long story short a stainless barrel might not be the way I want to go with an SBR for shooting a generic load with off the shelf cheap ammo.

[DutyUse]

10.5 or 11.5 would be my suggestion... With leaning more to the 11.5

[alamo5000]

10.5 or 11.5 would be my suggestion... With leaning more to the 11.5

Sorry my post got screwed up. I accidentally submitted before I was done posting.

My question isn't about length but rather about type... melonite vs nitride vs chrome lined...

[alamo5000]

Long story short I think it's pretty academic as I probably won't wear out a barrel but let's say if I was going to put those types of barrel on a machine gun... what would happen with those three? The only known would be the chrome lined... those are proven... I am just not sure about the others....

[GOST]

Long story short I think it's pretty academic as I probably won't wear out a barrel but let's say if I was going to put those types of barrel on a machine gun... what would happen with those three?

If you were using the barrel for full auto then accuracy isn't your main goal, and the benefit of the stainless bore having no growth from a process isn't needed. So for full auto I would just go with chrome lined since its proven.

Since barrel length affects velocity rather than accuracy. To me what I like about a SBR is that you can use a heavier profiled barrel that is very stiff without increasing the swing weight of the rifle as much. So if reach isn't what the rifle is intended for, a heavier profiled stainless could be very accurate.

[GOST]

This is the barrel I've got for my SBR I'm working on.

http://micromoa.com/12-5-midlength-fluted-5-56-nato-1-7-barrel/

[alamo5000]

If you were using the barrel for full auto then accuracy isn't your main goal, and the benefit of the stainless bore having no growth from a process isn't needed. So for full auto I would just go with chrome lined since its proven.

Since barrel length affects velocity rather than accuracy. To me what I like about a SBR is that you can use a heavier profiled barrel that is very stiff without increasing the swing weight of the rifle as much. So if reach isn't what the rifle is intended for, a heavier profiled stainless could be very accurate.

More or less the idea is to get to a really tough barrel that I can abuse a lot more than what I do to my stainless barrel. Yeah, it would be nice to have something that I could run full auto on. Who knows. I might put a slide fire on it and go. I just want something that I won't need to worry about. Of course I am huge into accuracy, but for the concept behind what I am talking about would not be built around pinpoint accuracy. It would however need to be more tough and have a longer life.

I am more or less curious how the melonited and nitrided barrels stack up in all this, because being honest I could probably live with something tougher than stainless but not quite machine gun level.

[GOST]

Another thing to consider is that if you can afford the amount of ammo it will take to shoot out any of the 3 options, then buying a new barrel every now and then isn't that bad. A properly treated stainless barrel is very durable. To me I wouldn't make the durability between those 3 options be the limiting factor on choosing a barrel for a SBR.

[alamo5000]

Basically with my AK I can really get at it and abuse the hell out of it. If I shot a case of ammo in an afternoon through it I really wouldn't be worried about it. I kind of want the same thing in an SBR... where I could realistically run the hell out of it.

I know there are a few of you (or more than a few) who are laughing going 'a case of ammo? in an afternoon?'... yeah point taken but that's the concept... to have a barrel that will last over time to being run hard.

[GOST]

A properly treated stainless can take a whole lot more abuse than you think.

[alamo5000]

Another thing to consider is that if you can afford the amount of ammo it will take to shoot out any of the 3 options, then buying a new barrel every now and then isn't that bad. A properly treated stainless barrel is very durable. To me I wouldn't make the durability between those 3 options be limiting factor on choosing a barrel for a SBR.

You nailed it on the cost of ammo... I am also not above buying a new barrel every now and then. That said if I can buy a barrel that will stand up from the get go that will be better. I might pay twice as much but then again I might get more than twice the life.

Also it's worth noting that I might not be the only person shooting and buying ammo. If I go out with the guys and tell them to bring a case of ammo each... I want to be able to run that sucker and not worry. The ammo costs might not all be mine.

[GOST]

Is this thing gonna be belt fed? If you have no concerns about accuracy then get a double chrome lined hammer forged FN barrel.

[alamo5000]

Is this thing gonna be belt fed? If you have no concerns about accuracy then get a double chrome lined hammer forged FN barrel.

No, no... nothing like that. I wish I could get a belt fed [:D]

That said though, just like I said above I might not (and probably won't be) the only shooter. We shoot and socialize and just basically have fun. It's not out of the ordinary to have 3 or 4 of us get together and shoot. If we run a case or two of ammo so be it. Basically I want to plan for and build a gun with those kinds of contingencies in mind.

The chrome lined is obviously proven, I am just not sure how other styles and types of barrels would hold up occasionally being run like that.

[DutyUse]

I agree with Gost. For what your wanting a good FN barrel like this 11.5 BCM BfH seems like a perfect candidate. And just like he said because there shorter you can get away with a thicker profile. This BCM is a hoss but still about the same weight as one of my 16" govt profiles.

http://images.tapatalk-cdn.com/15/11/22/a418adc941f4c7f51b3704713da5d87e.jpg

They can take a lot of abuse, and in my experience a good FN barrel will produce 1.5-2" groups. Maybe a touch tighter because of the short stiff nature of SBR barrels. More the adequate for good accuracy.

I am however very intrigued by those micromoa 12.5 middys

[BoilerUp]

I'm a melonite fan-boy. How about SS accuracy with more longevity than chrome lined? I wish Harrison made these in 10.5-11.5": http://www.ar15performance.com/inc/sdetail/11562/14399

[Dstrbdmedic167]

I'm a melonite fan-boy. How about SS accuracy with more longevity than chrome lined? I wish Harrison made these in 10.5-11.5": http://www.ar15performance.com/inc/sdetail/11562/14399

I have the 12.5" and I absolutely love it!

[Former11B]

I'm a melonite fan-boy. How about SS accuracy with more longevity than chrome lined? I wish Harrison made these in 10.5-11.5": http://www.ar15performance.com/inc/sdetail/11562/14399

Ask them if they would cut one down for you

[DeviantLogic]

In terms of longevity, chrome lined and nitrided barrels will both hold their own. I've seen some reports that chrome lined will last x% longer than nitrided or vise versa, however it always depends on a lot of variables (rate of fire, caliber, ammunition specs, temperatures reached, thickness of chrome lining, etc).

Broad strokes: For us mere mortals who aren't routinely performing mag dumps while shooting their 5.56 AR's, the nitrided barrels will generally last as long as, or longer than a chrome lined barrel. Start increasing the rate of fire and caliber used, and you'll start seeing that chrome lined barrels will have a higher longevity.

For clarity purposes, I'm considering Melonite, QPQ, Black Nitride, etc as "nitrided". They are all roughly the same thing.

[Stone]

A chrome-lined barrel cannot be manufactured to the same tolerances that a non-lined barrel can.
In other words, the bore must be drilled oversize, and the grooves cut deeper than normal etc., to allow for the thickness of the plating, in order to achieve a desired final dimension. Which may actually be a bit over or under spec, depending on how the plating process goes that day. Not to mention flaking, pitting and burrs in the bore associated with chrome lining. Also compare the corrosion resistance of chrome to FNC, FNC barrels are the clear winner. Think of your moms 1976 Buick's chrome bumper that has rusted out. Chrome lined barrels are almost extinct. The real enemy of any barrel is heat, a few mag dumps here and there aren't anything compared to shooting full auto.

[Stone]

I have been researching hard use barrels and have been looking into Nitrocarberizing a SS barrel. One, because of a stainless barrels legendary accuracy and two, because of the abuse a NC'd barrel can take. I recently had a conversation with Joel from V7. Since they are now a sponsor here I don't think he will mind me posting some of that conversation here.

> Body: Can you tell me if any of your customers who have bought a barrel from you have had it Nitrided? I think your barrels are amazing and would be looking to extend the service life if I purchased one. Would this void the warranty? I run my rifles pretty hard with an extended shooting schedule and am concerned with the longevity of a SS barrel. Thank you! XXXX

> I have not had anybody tell me about doing it so far. Here are a couple issues that can arise. The barrel extension should not be subjected to the 900-1050 degree bath because it will mess with the heat treat of the extensions 8620 alloy. The core of the extension is kept soft/tough and the surface is hardened to about a 20 thou depth for long wear life. Nitriding does mess with that, how bad? not bad but we never tested the long term effect, main issue would be the core hardness, to hard and it can crack. People have done it and I have never heard of any issues but not some thing we could warranty. The rest of the barrel would do great Nitrided as long as they knew it was 416R and did not let the nitride penetrate to deep. After testing maximum penetration with Nitride on a few different stainless steels to see how it preformed, we found chunks of rifling coming out of the barrel in less than 10K of hard fire. Thin Nitride good, thick bad at least for barrels that is. If you buy
> one of our medium barrels and it shoots out on ya I will replace it, if you buy a thin light barrel I can't make that deal, maybe that helps. We will add a Nitrided version of our barrels at some point when we get ahead, but it will be next year and we will make sure we get them Nitrided before the barrel extension goes on LOL. Take care and have a good one.

> Kindly, Joel~

>Thanks for the thorough response Joel! If I did buy one of your medium contour barrels what kind of round count can I expect out of one of them if it would be run pretty hard. Thank you XXXX


With hard full auto use I have seen really good accuracy for 5K and then the groups slowly open to over 1moa after 8-10K. With hard semi auto use good accuracy is had until about 7-10K depending how hot you get it over time. Then after 10K or so the groups slowly open up. Most good stainless barrels will still out shoot your average new chrome lined after even 10K.
Bullets will still stabilize and shoot under 2moa even at 15-20K then some where after that bullets start to tumble. This is general info and can change a bit depending on ammo used, if a suppressor is used, and many other factors.

Joel~

I think good quality SS barrels are tougher than we give them credit for. Stone

[mustangfreek]

Good info, thanks


OP for whatever it's worth my 10.5" RA stainless shoos very well.

[Joelski]

FWIW, my 10.5" is chrome-lined as well and I welcome the day I get to pick a new one, but only because I'm hoping honeycomb dimpling is sorted-out out by then. Also, the connotation of me shooting out that barrel would mean I've won the lottery at some point, since it's .300 BLK, and not cheap to shoot!

You shoot 3k-4k rounds in a session with your buddies? Hell, that sounds more like basic training than a Saturday afternoon! [:D]