AR spare parts kit

[breakingtime91]

I do not shoot a high round count through my AR but it is starting to slowly get up there. What spare parts should I have on hand and what does the maintenance schedule look like?

[Jay Cunningham]

I'd have a complete bolt assembly at a minimum.

[ASH556]

Anything can happen, but assuming you're shooting a quality AR15 from BCM, DD, etc, then I would start with a few of the McFarland 1PC gas rings. That's the best bang for the buck in terms of what really wears on AR's. The check is whether or not the bolt will support of the carrier when stood on its head. My experience is around 2,500-5,000 depending on firing schedule and how over-gassed the rifle is.

As Jay mentioned, a complete bolt is also a safe bet. That covers gas rings, extractor spring, extractor, the bolt itself. You might add a firing pin to that as well. Other than that, shoot, lube, repeat until around 10,000. Then (again depending on firing schedule) begin to check the barrel for loss of accuracy.

Oh, and an action spring. That's another relatively cheap spare (less than $10) to have on-hand. I had to replace one at 1500 rounds, but it was a little short from the factory.

[Kyle Reese]

Spare extractor, bolt, gas rings and firing pin at a bare minimum.

[ReverendMeat]

Safety selector springs+detents, takedown pin springs+detents, buffer retainer+spring. Even if you will never need them, might be you'll have a buddy who tried pulling something off his lower without paying attention to all the junk that came falling out with it.

[breakingtime91]

thanks guys. slowly getting this stuff together! I'm finding that convincing other people that stuff like this is important is really difficult...

[pdb]

I'd suggest also having spare cam pins and firing pin retaining cotter pins. Losing things during disassembly for cleaning is more common in my limited experience than actual breakages.

I do have a spare bolt, spare extractors and extractor springs, and spare firing pins in my range bag.

[Wayne Dobbs]

A spare bolt assembly and ideally an entire BCG is very desirable since the majority of problems you encounter with the system start there. The ability to simply drop in a known quality/performance, lubed BCG on the gun and keep shooting is very nice. And, if that move works, you know exactly where to start your repair efforts. Get a Colt or BCM BCG and you're very good to go.

Failing that, I suggest to my armorer class students that they have on hand the items to completely overhaul a bolt/BCG: complete extractor assembly, bolt rings and cam pin. An ejector assembly is OK too, as is the firing pin, but those hardly ever become necessary. Firing pin retaining pins should also be kept for those times you lose them. I strongly suggest the bolt be overhauled with the above parts every 5K rounds, as it stays ahead of most parts failure incidents by doing so.

[Wayne Dobbs]

Anything can happen, but assuming you're shooting a quality AR15 from BCM, DD, etc, then I would start with a few of the McFarland 1PC gas rings. That's the best bang for the buck in terms of what really wears on AR's. The check is whether or not the bolt will support of the carrier when stood on its head. My experience is around 2,500-5,000 depending on firing schedule and how over-gassed the rifle is.

As Jay mentioned, a complete bolt is also a safe bet. That covers gas rings, extractor spring, extractor, the bolt itself. You might add a firing pin to that as well. Other than that, shoot, lube, repeat until around 10,000. Then (again depending on firing schedule) begin to check the barrel for loss of accuracy.

Oh, and an action spring. That's another relatively cheap spare (less than $10) to have on-hand. I had to replace one at 1500 rounds, but it was a little short from the factory.

That McFarland is great in concept, but I've now seen enough of them be undersized and fail gas ring tests, that I've decided the GI rings are the best place to be. If they work in your carbines/rifles, that's good, but not as a mass recommendation.

[Josh Runkle]

For myself, I've found that it is far more useful to ensure that I have things like the appropriate tools to fix optics, mounts, lights, etc, before I have spare parts. I always have a spare bolt/bcg as well. If this is obvious to the OP, then please disregard.