We’ve been bombarded with a variety of coatings and platings over the past few years, most of which are called “proprietary” and given a cool name. In reality, there aren’t a whole lot of finishes or metal treatments out there. Many are just variations on a theme, such as all the derivatives of nitrocarburization and nickel plating.
Nickel boron is related to electroless nickel plating and electroless nickel with teflon (also known as Robar’s NP3) with regard to the plating process. Nickel boron is reported to provide “permanent dry lubricity”. In other words, less friction amongst the reciprocating parts, as well as where they interface with static components.
It didn’t really occur to me that this might lead to lower operating temperatures. In fact, when I noticed a discrepancy between a rifle with a nickel boron BCG and a similar rifle with a standard, phosphate finished BCG, I wasn’t sure what to think. They used different rail systems and gas system lengths. Initially, I chalked it up to those minor differences. Then, I decided to use a standard BCG in the rifle that was originally equipped with the NiB BCG, using the same test protocol. After that, I repeated the test, twice, with each BCG, allowing the weapon to cool to ambient temperature between strings of fire.
The test was performed by firing 80 rounds of centerfire ammunition as quickly as possible through the AR-15 pictured below:
No malfunctions were experienced during any of the 5 strings of fire.
I then measured the temperature of the gas block, chamber, bolt face, and handguard (in four locations) immediately after firing and at two minute intervals out to 10 minutes.
For the sake of comparison, I have included the temperature of an M4 type carbine equipped with a KAC M4 RAS handguard. The rifle above was equipped with a Daniel Defense OmegaX 9.0. None of the rails had any covers during the testing.
Gas block temperature profiles were nearly identical for all weapons.
The same goes for chamber temperatures.
Bolt face temperatures, however, were another story.
The bolt face of the nickel boron plated BCG stayed, at its peak, 13 degrees cooler than the same weapon with the standard BCG, and 17 degrees cooler than the M4 carbine with the KAC M4 RAS.
Here is the nickel boron BCG compared with the POF RDIK and POF P-415 uppers, which underwent the same test (again, we’re talking bolt face temp here):
As always, I’m not a scientist and this was not a scientific test, but I do feel fairly confident in the results, given that I double and triple-checked the numbers and nothing was outside of a small margin of error. The above numbers are the average of said tests and retests.
I do realize that this was a sample size of one and that the limited testing doesn’t definitively prove anything. I do think that it is an interesting result that I would like to follow up on after I get more ammo and possibly more nickel boron plated BCGs.