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Posted: 1/20/2008 5:39:14 PM EDT
| I am a little confused, can somebody explain to me in laymens terms, what we should look for in a good quality bolt? I have seen charts with different items on them and how various brands compare, but I honestly do not know what most of it means, like MPI bolts, shotpeened, something being tacked? Anyone? |
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MPI = Magnetic Particle Inspection, Used to test for weakness BEFORE it causes you problems Shotpeened = Just that, small steel shot pellets impacting the bolt to improve (make more durable) the surface crystalline structure of the bolt (similar to forged) Tacked = Likely meant "Staked" = The bolt carrier key is attached with two bolts to the bolt carrier itself. Some metal from the key is "staked" by impressing material into the bolt head to prevent it from loosening. Some manufacturers don't stake, or stake improperly. Search other threads for more information and company specifics. |
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I don't know what you mean by "tacked" (unless you are asking for this thread to be tacked by the mods), but one of the things you see discussed a lot when it comes to BCGs is the "staking" of the gas key screws. "Staking" refers to how well the two screws that hold the gas key on to the bolt carrier are fastened by the manufacturer. These two screws coming loose over time is the root cause of a lot of functional reliability problems with the AR-15 system. Unfortunately, too many manufacturers skimp on their gas key staking these days. I don't have a picture of this on my hard drive, but there are other threads on the site that talk about this where you can see pictures - try a key word search for "gas key." How do you solve the problem? I just keep a few spare BCGs on hand. If the gas key screws ever do shoot loose on you, it is possible to loctite them back down, but the most desireable situation is to never have them come loose at all. |
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