Hello, On my ongoing AR15 build the complete upper I purchased came with a stock BCG. I purchased one of the custom M16 BCGs from Spikes Tactical and it seems to function just fine -but- I'm reading I need to pull the extractor and check the rifle with a set of go / no go headspace gauges now. Is this true? Is it something that has to be done every time you replace part of or the entire BCG?
Is it absolutely necessary? No. With this day and age of CNC Machining and tighter tolerances, you are PROBABLY fine. That said, in our shop, we do a Go/No Go headspace check for free - it takes about 2 minutes and then you know you are good to go. Safety first is always the best practice in my mind. Some have suggested using a dummy round from a previous batch of ammo you had successfully fired. Actually, someone suggested first using a live round, then later a dummy round. You can do that, it's not for me personally - but I suppose it would work in a pinch. I don't believe you have any old ammo that you successfully fired through the weapon, since it's a new build, so a headspace guage would be worth the limited investment if you like to tinker and perhaps build a few more yourself. You can get the basic one from Brownells for about $20 shipped to your door. Or you can get the set, which is about $40 to $50 depending on where you shop. If you are going to build/tinker one or two rifles, and leave them alone, it's probably not worth the money. However, if you plan on doing some major kind of work, or building a gun for someone else, it might be worth it to you. I would own one as part of my standard range kit, but we have them in the shop that I can use for free. JD
If you don't have access to headspace gauges and it shoots fine, continue to shoot & have fun. Ars are designed to accept all same standard dimentions bolt carrier/bolt interchangability, and do not require timing. If it's radically different or different sized, then it would be good idea to check headspace.
