Stx Coatings

Can you tell me any other part that takes more abuse than a BCG inside an AR-15? They are in many ways the heart of your AR. So, there's a lot of bolt carrier groups out there ranging from under $100 all the way up to $500. And it can be hard to know w Add in the fact that there are a lot of acronyms Shopping for a bolt carrier group can be a tad bit overwhelming. So, I'm CJ with AT3 Tactical and I wanted to help answer these overwhelming questions. So, for t So, with that in mind let's go through some common materials that are used in most BCGs. Before we talk about specific materials it's important to remember that some BCGs mix and match materials for certain components such as the bolt and the carrier for example. T So, the first material we're going to break down is Carpenter 158 and t S. military by a company called Carpenter Technologies hence the name. Now there's a lot of material science going on here so I want to try to keep t And typically it has a chemical phosphate coating on it to enhance resistance to wear and corrosion but we'll talk more about coatings later on in the video. What's great about C158 is that it's common, it's easy to work with and it's durable so it's going to be one of the most affordable options out there in terms of materials for BCGs. It also comes in with a super strong rating of 1690 mPa. What does that even mean? Well let's break it down really quickly. Tensile strength or how strong a material is when it's being pulled apart is often measured in somet One megapascal or mPa is roughly equal to 145 pounds per square inch or psi. So when we talk about tensile strength we're looking into how much force a material can handle before it breaks. For example mild steel can handle about 36,000 pounds per square inch while stronger materials Next we're going to look at 9310 steel and it has an mPa of about 930 to 1200 and it's known for its Now 9310 steel is also the best choice for applications Now because of the advantages of t Next we have 8620 steel and it has an mPa of 620 to 880 w Now t If it is used for the bolt itself I would recommend avoiding t Really in the end no matter what material you go with the locking lugs tend to be the thing that breaks first so high grade materials will resist wear better so don't skimp on reliable stuff here especially for components The next the coefficient of friction or the COF is a simple way to measure how slippery or grippy two surfaces are when they touch. It's just a n For example t 1 meaning it'super slippery. T On the other hand rubber tires on dry pavement have a much 8 to 1. 0 w So the first coating that we're going to talk about is phosphate and that has a COF range of about 0. 3 to 0. 4. Now phosphate also known as parkourizing coatings provides a moderate friction resistance w Fossfate coating finish should still have a chrome lining on the inside of the gas key and inside the carrier where the gas rings ride to make sure that the rotation of the bolt is still smooth. Even though these are old and still the mill spec standard some people The roughness of the phosphate finish will eventually wear down to become a much smoother finish on high wear parts and areas And what's really good about phosphate is it's the most economical of all the finishes so if you're looking for the cheapest most available coating for an occasional range use gun I would say go with t Next we have nitrite and t 2 to 0. 3 making it a slight bit more slick than something Nitrite coatings offer a lower fritc People really It's easier to clean and since the coating is much smoother it doesn't require a chrome lining on the inside of the carrier or the gas key since it's already smooth enough inside. Now it's going to cost more than your standard phosphate coating due to t Honestly though these are really subtle differences if you don't shoot often so if that's not you can probably just stay with the normal phosphate coating but if you want somet Nickel boron has a coefficient of friction of about 0. 120. 2. Now nickel boron coatings are buttery smooth offering one of the lowest coefficients of friction among any of the coatings. T Again it's ultra sleek and it's easy to clean similar to nitrite but it's popular in the mid to One t For t It is super rare but it is something that does happen occasionally so I thought it's important for Next up is DLC and no I'm not talking about downloadable content. T 05 to 0. 1 w DLC coatings have an extremely low coefficient of friction offering the slickest surface of any of the coatings listed here. Known for its hardness and wear resistance DLC reduces the friction dramatically making it ideal for Huge bonus of this coating especially for me Get your wallet ready because these are of course going to be the most expensive ones that we're talking about today. I do have to include titani 2 to 0. 6. Titani Again just One of the last the M4 or M16 BCGs have more material in the back of the BCG making them heavier reducing wear and slowing the action down better for reliability for faster rates of fire You can get M4 or M16 rated BCGs even if your gun is an AR-15 and for that matter most modern day bolts are going to be rated as M4 or M16 bolts just to say that they are designed for The next set of features we want to look at are enhanced designs. I'm talking about features that don't come with stock BCGs that manufacturers throw into spice t For example, Sharp's XPB have angled lugs for smoother cycling and reduced lug stress hopefully preventing them from breaking over time. Landtack also has specialized cam pins to reduce wear and friction especially in over gassed systems. There are also super light weight BCGs that are milled down to reduce excess material and therefore reduce the weight of for example a competition gun but you'll also want to invest in an adjustable gas block and buffer to tune the whole system in just the right way to get that felt recoil impulse as low as possible. And when you're looking for a BCG and you see somet So let's look at those just real fast. So first of all MPI stands for Magnetic Particle Inspection and t So when something says that it's certified MPI tested That doesn't mean that this is foolproof or that cracks won't form later on but The next testing protocol is HPT or How the Now the next t A lot of gas keys are going to look What a properly staked gas key prevents is the screws from backing out w So what you want to do here is when you take it out of the box look carefully at those screws and make sure that there's proper interference with the screws from the gas key being staked. That way those screws aren't going to back out on you at all. Now that we've covered all the materials, coatings, features and testing protocols that BCGs can come with t Again I'll ask you are you building a budget range plinker or a rifle that you trust your life to? T Now I hope I've been able to help you understand the cost of BCGs but if you still want to know more about the fundamentals of BCGs, how they work and their unique parts go check out t