BCG coatings/treatments

[7.62fmj 0]

Nickel Boron, Melonite, NP3, Nitride... list makes my head spin.

Who has experience with different BCG treatments, are they worth the extra cash over phosphate?

[MidwestPX 172]

Out of what you've listed, I think nickel boron is the best value as far as increased performance over a properly phosphated BCG.  Real nickel boron (not electroless nickel with a boron modifier) is very hard and has excellent corrosion resistance as well as self-lubricating.  It's also easier to clean, moreso than melonite, NP3, or nitriding.  That being said, my personal BCGs are all phosphated.  I offer nickel boron because customers want it and it's a good product but for my uses, I don't find it to be a must-have.  I also don't clean my guns so the big benefit of easier cleaning is lost on me.  I know, I'm a savage.

[High Exposure 5,670]

 That being said, my personal BCGs are all phosphated.  I offer nickel boron because customers want it and it's a good product but for my uses, I don't find it to be a must-have.  I also don't clean my guns so the big benefit of easier cleaning is lost on me.  I know, I'm a savage.

I like you. Let's be friends

 

What MWPX said!

[Jon 264]

I like you. Let's be friends

 

What MWPX said!

 

Ditto. This is why I buy things from Ty.

[MidwestPX 172]

Cleaning my guns is like the making the bed.  I'm just gonna mess it up again soon, why bother??  And I'm lazy...  

[High Exposure 5,670]

Quick off topic statement. Apologies to the OP.

 

MidwestPX, you constantly offer excellent advice and product knowledge. As I am sure you, and many others here, can tell, I am very picky about what I buy and who I buy from. As the resident "gear nut" and "training junky" amongst my friends and co-workers I am asked often about good gear and shop choices by guys that will be betting their lives on the gear they buy, as such I am even more picky when it comes to who I recomend to others that they buy from. I just wanted to let you know that I am impressed and will be placing future orders to your store and will be recommending that others do the same. It is refreshing to see a shop owner that is as knowledgable as you are and has the integrity to not carry crap gear or to recommend unnecessary items just to make a quick buck.

 

Again, apologies to the OP, I just needed to say that.

 

Back on topic: you do not need any fancy coatings on BCGs, you will be much better served spending that extra dough on ammo and a training class.

Edited October 21, 2013 by High Exposure

[MidwestPX 172]

Quick off topic statement. Apologies to the OP.

 

MidwestPX, you constantly offer excellent advice and product knowledge. As I am sure you, and many others here, can tell, I am very picky about what I buy and who I buy from. As the resident "gear nut" I am asked often about good gear and shop choices by guys that will be betting their lives on the gear they buy, as such I am even more picky when it comes to who I recomend to others that they buy from. I just wanted to let you know that I am impressed and will be placing future orders to your store and will be recommending that others do the same. It is refreshing to see a shop owner that is as knowledgable as you are and has the integrity to not carry crap gear or to recommend unnecessary items just to make a quick buck.

 

Again, apologies to the OP, I just needed to say that.

Thanks, I appreciate that.  I try to be genuine in my advice, both public and private, because I believe in maximizing the value of a hard-earned dollar.  If I don't carry what best fits someone's needs, odds are that I know someone who does and have no problem sending someone to a competitor because the owner of the other shop is likely a personal friend of mine.  You wouldn't believe how friendly most of us owners are with one another and how much we help each other behind the scenes.  It's an aspect of the industry that I'm really proud to be a part of...that network of owners who can co-exist and be helpful to one another yet be able to build thriving businesses.

 

People tell me I'm a terrible salesperson because I'll tell someone to buy $30 MOE handguards for their first AR and spend what they would have spent on a Centurion rail on ammo to practice...ammo that I don't even sell.  But I believe it comes full circle and when the customer is ready for that rail, they'll come back to pick my brain for an honest recommendation and ultimately buy it from me because I offer good service and pricing.

[raz-0 1,259]

IMO there's only three coatings to consider. 

 

1) standard phosphate with appropriately chromed bits. Decent and cheap. Corrosion resistant and a known quantity that works. 

 

2) nickel boron. It's hard, slick, and doesn't flake like regular chrome. The only question I haven't found an answer to is if it is subject to the risk of hydrogen embrittlement like a normal chrome plating process. Even if it is, there doesn't seem to be rampant issues with chrome plated bolts so I don't worry about it to much. It's not magic though, as baked on carbon will stick to it almost as much as it will to chrome, and you still need tools to clean the chrome lined bit of the BCG if you leave it long enough. Same applies here from many first hand accounts. It also can discolor under heat similar to stainless steels that get that blue and pink sheen, but slightly different. normal chrome doesn't seem to do that. 

 

3) melonite or melonite QPQ over a properly polished surface prep on NON-stainless ferrous metal. In this situation it cleans easier than phosphate, is very hard, and on non stainless steels it provides corrosion resistance. It also has no dimensional change because it si a chemical reaction that alters the surface rather than a deposited coating. Biggest risk would be on AR bolt lugs as any defects that could cause stress cracks will be exacerbated by the high temp treatment. 

 

As for other processes

 

1) NP3. this is a nickel chrome coating modified with teflon. PTFE + the temps in a rifle (in the barrel, BCG and DI gas system) strike me as a bad combo for the PTFE not burning off or breaking down as max operating temp for PTFE is 525F. In fact, outside of treating bits of trigger groups with it, I can't find an appropriate application for this stuff. I've encountered it on magazines and slides as well, and it's just too damn slick for things where fumbling due to poor grip is ever a concern. Once the coating fails, it tends to start flaking, much like normal chrome plating. 

 

2) Nitride. That's a VERY broad term. Melonite is a molten salt nitriding process, as is tennifer. Ion bond Diamond Black is a PVD low temp nitriding process. It is very hard and like all the ones in the above section, if the coating is breeched, it doesn't tend to flake and spread the breech. It also provides no corrosion resistence as it is essentially a sputtered coating, and really doesn't offer ocntinuous coverage. However, due to this, it DOES seem to hold lubricants pretty well provided they don't evaporate easily. The Gold TiN finish is a similar process. For other molten salt processes, you have to look at the tmeperature of the bath, and the nature of the salts and chemical reaction with the substrate. The only real concern in common with them is that molten salt baths are hot, and any part that is thin can become brittle due to the bath effectively over hardening it via heat treatment (for example Melonite usually involves a pre heat to about 800F and the bath is about 1100F). IMO nothing on a BCG is something to be concerned about for this. The various PVD nitride processes are IMO a waste of money. The only thing they bring to the table is if they are used to treat a polished finish, they wil help preserve the smoothness as long as the underlying metal isn't too soft. Other than that, they look pretty while doing no harm. 

 

3) Hard chrome. It can flake, and it can induce hydrogen embrittlement. There is a recipe to deal with that which involves a post plating baking session, which the AR bolt and carrier are good candidates for it being easy to do. Like I said, I haven't seen a spate of failures on chrome bolts, so I'm assuming the makers are doing this. It can flake if you manage to damage the coating, and thus the damage spreads. The flaking can cause the rifle to suffer operational malfunctions. Quite a while ago there aws a batch of DPMS chromed BCG with this issue. 

 

My personal opinion is I'd consider nickel born and melonite on the carrier, and stick to phosphate on the bolt. 

[7.62fmj 0]

Thanks for all the feedback y'all. Build is going smoothly, there's just so many options out there it's hard to see through the manufacturer hype, hence all my questions here.

[RUTGERS95 890]

do they salt bath nitride bcgs like barrels?

 

op, just get a psa enhanced bcg for 100 and be done.  It's got everything you need at a fraction of the cost and you'll never know the difference.  In my rifles I have the full gambit and there is no such thing as the bcg not needing the same cleaning.  The only bcgs I own that truly only require a wipe down are my lwrcs but they are pistons.

[raz-0 1,259]

do they salt bath nitride bcgs like barrels?

 

op, just get a psa enhanced bcg for 100 and be done.  It's got everything you need at a fraction of the cost and you'll never know the difference.  In my rifles I have the full gambit and there is no such thing as the bcg not needing the same cleaning.  The only bcgs I own that truly only require a wipe down are my lwrcs but they are pistons.

 

Yes, I have a PWS DI carrier. IT cleans up REALLY easily, I was actually surprised as that was not one of the reason I gave it a try. Ice arms is in theory coming out with a melonited whole BCG soon. 

[NickySantoro 211]

I carried an M16A1 in conditions that were conducive to rust an corrosion. By staying on top of maintenance, I never had a problem. In my most non-expert opinion, these special coatings are a solution in search of a problem.

FWIW
YMMV

[raz-0 1,259]

I carried an M16A1 in conditions that were conducive to rust an corrosion. By staying on top of maintenance, I never had a problem. In my most non-expert opinion, these special coatings are a solution in search of a problem.

FWIW

YMMV

 

Yes and no. I think alternative coatings are not likely to bring much to the table in terms of basic performance and reliability. The internally chromed and externally phosphated mil-spec design works well and are not plagued by inherent shortcomings. That being said, I think they bring a benefit in terms of manufacturing. The more viable options that don't trade away any of the pluses of the mil-spec phosphated carrier mean there's more total manufacturing capacity, more vendors, and less choke points in the production pipeline. Additionally it seems to provide more flexibility to creative manufacturers who want to try something different with BCGs like different profiles for piston system carriers (many of them are polished and melonited). IMO those thing benefit the consumer, although not in the form of brand X or technology Y is clearly superior. 

 

Also my pws melonited carrier cost all of $10 more than what I could find a phosphated one for at the time. That's not a lot of ammo or training, and I figured I could see if it was a good approach from an end user perspective. It works fine, and seems to meet or exceed the mil-spec part in performance. It wasn't my first or only AR, so taking that chance wasn't that big a deal. 

[7.62fmj 0]

Appreciate all the answers guys, not looking to pick up a whole bcg since the 6.8 ones are more expensive. I've found it'd be cheaper to buy a stripped carrier then a 6.8 bolt. But the info on treatments has been real informative.

[RUTGERS95 890]

oh nice...6.8 is the caliber that make the AR what the AR was supposed to be....