5.56 Barrel

[MegademiC]

Having machined a Faxon barrel before, I can personally attest to their nitride being top notch. The problem is that to achieve the hard, rust proof types of nitride, it has to be done at extremely high temperature, and I can't imagine that's good for the barrel. It's like 1200 degrees for hours on end that these barrels get dunked in.

Now think of this. It's the heat that kills barrels, not the friction of the bullet going down the pipe. In a zero heat environment, a barrel could last indefinitely. Pistol barrels almost do, especially something like .45 ACP. Any finishing done to a pistol barrel is solely to prevent corrosion and make it look nice.

On a rifle barrel, though, the biggest factor in longevity is heat over time. And there are thresholds where you go much above a certain temperature and it's going to dramatically reduce lifespan, and obviously those thresholds are well below 1200 degrees.

Theres more to unpack here than im getting into, but thats not how metallurgy works.

At a high level, erosion and temper are not the same thing.

[1168]

Theres more to unpack here than im getting into, but thats not how metallurgy works.

At a high level, erosion and temper are not the same thing.

I’d like to hear more, when you get a chance.

[MegademiC]

I’d like to hear more, when you get a chance.

Ok, have some time - see below.

Having machined a Faxon barrel before, I can personally attest to their nitride being top notch. The problem is that to achieve the hard, rust proof types of nitride, it has to be done at extremely high temperature, and I can't imagine that's good for the barrel. It's like 1200 degrees for hours on end that these barrels get dunked in.

Now think of this. It's the heat that kills barrels,
Not exactly - it's wear and erosion.

not the friction of the bullet going down the pipe. In a zero heat environment, a barrel could last indefinitely. Pistol barrels almost do, especially something like .45 ACP.

And a barrel below it's melting point will last indefinitely. You need the heat, AND the stuff going down the barrel to wear it out.
What happens inside a pistol barrel is much different than a rifle barrel.
Pressure: 20ksi vs 55ksi
Speed: 900fps vs 2800fps+
You have a hotter, higher pressure environment with solids (powder) impacting the surface at a higher velocity. All 3 lead to the faster wear than pistols.
This is also why 22-250 has a shorter life than 223, even if the entire barrel never gets very hot: 65ksi, 4,000fps, and 50% more powder going down the tube.
The hotter the barrel, the more susceptible it is to wear and erosion.


Any finishing done to a pistol barrel is solely to prevent corrosion and make it look nice.

On a rifle barrel, though, the biggest factor in longevity is heat over time. And there are thresholds where you go much above a certain temperature and it's going to dramatically reduce lifespan, and obviously those thresholds are well below 1200 degrees.

1200F? Thats the sub-critical annealing temp for 416. Since the barrels are almost certainly annealed, taking them back to that temp wont change the wear characteristics at all. That said, if they cool it improperly, they could introduce stresses into the barrel that affect accuracy.

[DG23]

FIFY

Do you really think it's a coincidence that nitride on centerfire barrels is exclusively a phenomenon of the commercial firearms market?

The brake rotors on my truck are Nitrocarburized.

Very, very similar to the Nitride you are talking about granting a slightly different process...


Between the resistance to heat damage and the corrosion resistance they are superior to 'regular' run of the mill / cheap rotors. Zero warpage so far after almost 30k of abuse. Look and 'feel' like brand new rotors still.

[Bellycrawl]

As to Faxon barrels, the company states,

"We stand behind everyone one of our products. Bottom line, if at any time you feel a barrel is not up to expectations, the team here is ready, willing, and enthusiastic to earn your trust and satisfaction."

I've had to send Faxon items back and their CS was top notch. I've also had great accuracy out of competitively priced barrels. Specifically, it was a 6.5 CM, fluted match barrel, but it was a .6 moa barrel with several match ammo selections. I've also had one 5.56 barrel, zero issues with that one and it shot well.

Hope this helps with confidence.

Blessings,