FNG questions on preventive maintenance

[User Name]

After reading many posts for several days it seems that preventive maintenance is something like the following: new bolt 5k, recoil spring 3-5k, hammer spring 10k, extractor 2-3k, barrel 10-15k. Like a pilot with an airplane I believe replacing parts before they fail. Am I on track with this? Thanks ahead of time for any advice.

[Robb Jensen]

After reading many posts for several days it seems that preventive maintenance is something like the following: new bolt 5k, recoil spring 3-5k, hammer spring 10k, extractor 2-3k, barrel 10-15k. Like a pilot with an airplane I believe replacing parts before they fail. Am I on track with this? Thanks ahead of time for any advice.

Bolts I wouldn't change until the rifle isn't headspacing anymore (closing on a NO-GO and FIELD gauge). More than likely a new bolt won't fix it, this usually requires a new barrel and bolt. I shoot bolts to bolt failure, or when replacing the barrel. New barrel always gets a new bolt (just the way I do it) All springs have a 'service life' and all springs will shorten with use. Buffer springs should be checked for length every couple of thousand rounds and when they approach the small end of the spec. they then should be replaced.

I replace the extractor, cam pin, gas rings, extractor pin, extractor spring, ext. buffer and Crane O-ring & FPRP every 3K rounds. I check the firing pin protrusion, buffer spring length, headspace every 3K (I also started keeping a log of the throat erosion in my own ARs). I'm anal and that's just me. 10K round for a hammer spring isn't a bad idea, they're cheap. If replacing the hammer spring at 10K you might as well also replace the disconnector and trigger spring. Mag catch and bolt catch springs I don't see worn out much but 10-15K rounds wouldn't be a bad idea to swap out too.