Chrome vs phosphate bolts

[Spooky1]

You've got to remember that there is a difference between treating the metal like QPQ does, and coating the metal like NP3 or chrome. I understand this is a simplification, but the point still stands, they are two different things.


I would also like to point out that different treatments can work very well for different applications. Chrome and various other carrier treatments aren't known to have issues, while those same treatments can create issues on the bolt.

Gotcha, I sorta been looking at them all as a "Coating" not 2 different things, and to be honest I really never thought about any more than that. Now I can start to understand this better. Thanks.

[1168]

I actually agree with mark on phosphate being an ideal coating; because it really holds onto lube. I have always felt like the phosphate BCG's absorbed some of the lube and then sweat it out when i actually get the gun hot. Whether or not this effect is simply my perception or an actual feature is another matter for debate.

I’ve witnessed this effect. It also happens with filthy BCGs regardless of coating type. Seems to happen more with some lubes than others. Looking at the ejection port while being the timer-bearer, it almost looks like the carbon is getting melty or something, even though thats obviously not happening.

Shipping parts from Massachusetts to Los Angles and back, as well as the cost of the proprietary finish was high. Colt suggested that local platers could plate just the critical areas with industrial hard chrome cheaper and faster.

Reading about some of the decisions Colt (and the gummint) made back in the day reminds me of the average AR buyer that has no idea how they should be made. I like to joke about this when people ask about my 605 clone. I’m certain they knew more than I’m giving them credit for; thats just how it looks to me as an outside observer reading about things older than I. Its amusing in retrospect.

How does Melonite or the dozen other names company's use for Melonite hold up?

I have 2 AR's with Chrome linined barrels, they are the 2 Colts that were my Dad's, all my other AR's have Melonite, or a type of Melonite coating on the bore. Some of my B.C.G's have Chrome lining and some don't, I also don't have any Chromed B.C.G's there either Melonite or Phosphate coated.

I have never been in the Military & was never a LEO I am just a dude that loves to shoot cool Firearms, it doesn't matter if the firearm was $125 or $12,000 I like what is cool to me. I do take my family's and myself safety seriously so I do quite a bit of training and I love to take S.D classes. I reckon I have been lucky or whatever but the only problems I have had in classes were either ammo & or mag related, or not enough lube. Like I said I am no ways a expert, & why I try take as many classes as possible, I have dang sure not seen it all so I am asking because I just want to learn.

Thank you..

If you are asking about melonited barrel useful lifespan, check with Criterion. They are held in high esteem and sell both chromed and nitrided barrels. They have some data on the website, perhaps in the FAQ.

I’ve posted my own anecdotes on this topic in the recent past on this forum. I could probably find those threads and PM you the link, if you like.

[JediGuy]

SIONICS Np3 BCG is my lone exception.

Yep.
Forward Controls Design would be included in that as well, if more expensive.

[AAMP84]

I’ve been buying phosphate bcgs and sending the cam pin, firing pin, and bolt sans the extractor out to be DLC coated. From what I read, DLC coated phosphate bolts will still retain oil similar to an uncoated phosphate bolt.

[Spooky1]

I’ve witnessed this effect. It also happens with filthy BCGs regardless of coating type. Seems to happen more with some lubes than others. Looking at the ejection port while being the timer-bearer, it almost looks like the carbon is getting melty or something, even though thats obviously not happening.

Reading about some of the decisions Colt (and the gummint) made back in the day reminds me of the average AR buyer that has no idea how they should be made. I like to joke about this when people ask about my 605 clone. I’m certain they knew more than I’m giving them credit for; thats just how it looks to me as an outside observer reading about things older than I. Its amusing in retrospect.



If you are asking about melonited barrel useful lifespan, check with Criterion. They are held in high esteem and sell both chromed and nitrided barrels. They have some data on the website, perhaps in the FAQ.

I’ve posted my own anecdotes on this topic in the recent past on this forum. I could probably find those threads and PM you the link, if you like.

If you don't mind I would appreciate that information you have. I will also check with Criterion.

Thanks!

[The_War_Wagon]

NOW you've got me second-guessing my Young National Match (chrome) BCG!!!

And bad reports on them over the years?

[lysander]

Shipping parts from Massachusetts to Los Angles and back, as well as the cost of the proprietary finish was high. Colt suggested that local platers could plate just the critical areas with industrial hard chrome cheaper and faster.

Reading about some of the decisions Colt (and the gummint) made back in the day reminds me of the average AR buyer that has no idea how they should be made. I like to joke about this when people ask about my 605 clone. I’m certain they knew more than I’m giving them credit for; thats just how it looks to me as an outside observer reading about things older than I. Its amusing in retrospect.

You have to remember, Armalite was based in Hollywood, so, shipping a batch of bolts, carriers, and a few other parts literally just 9 miles down the road to Los Angeles was no big deal. When Colt took over production, the distance increase a bit.

The one major advantage of a Electrolized bolt has over a phosphated bolt is corrosion resistance. And one of the big contributors to lug failure is a corrosion pit being the initiation point for a fatigue crack.

[MegademiC]

Got it. So you saw a sample of one.

As far as the grain structure is concerned - That is one of the reasons NiB has a lower coefficient of friction (not a greater one and certainly not 'abrasive'). When there is less metal touching between two surfaces you get - Less friction.

Yes, a sample of one. That's why I said "seem", it's not definitive by any means.

As for wear:
https://www.google.com/url?sa=t&sour...OwClZiu3JvrykB

[lysander]

Yes, a sample of one. That's why I said "seem", it's not definitive by any means.

As for wear:
https://www.google.com/url?sa=t&sour...OwClZiu3JvrykB

Yes, a sample of one, and some research data that seems to back up the assertion . . . .

[1168]

If you don't mind I would appreciate that information you have. I will also check with Criterion.

Thanks!

https://www.m4carbine.net/showthread...563&highlight=

You have to remember, Armalite was based in Hollywood, so, shipping a batch of bolts, carriers, and a few other parts literally just 9 miles down the road to Los Angeles was no big deal. When Colt took over production, the distance increase a bit.

The one major advantage of a Electrolized bolt has over a phosphated bolt is corrosion resistance. And one of the big contributors to lug failure is a corrosion pit being the initiation point for a fatigue crack.

Yes, it just amuses me to apply the retrospect-scope.