AR15: What wears out first?

I'm looking to get a kit put together so when my AR breaks, I will have a replacement part to fix it. Problem is, I have next to zero experience with ar's (first kit was ordered today) and I don't know what will break first. I realize that I probably won't break a part before I wear out the barrel but there's nothing wrong with being prepared, right?

I find that satisfaction with the round wears out first.
uh!
just kidding.
Keep the gas tubes clean and stuff. mm
I'd say... extractors/ejector maybe

A spare bolt is handy because bolts not only have wear issues of their own; but many common areas (extractor, ejector, springs, gas rings) can also be fixed quickly with a new bolt.

I have several AR's, some I have had for quite a few years and so far the only thing I have had to replace is ammo. I wouldn't get in too much of a hurry stocking up on spare parts. I would spend my money stocking up on ammo.

If you keep it clean and lubed you'll seldom (if ever) need to replace any parts. The highest wear item on an AR15 is the bolt head and extractor. As previously stated, keeping a spare bolt is pretty much the cheapest insurance.

With the spare bolt, do you just need to check headspace with a go/no go headspace gauge?

probably not. I mean, a bolt of the same manufacture should be identical in characteristics. Its not a bolt action anyhow, so headspace gets a tiny bit of play without devastation.

AR15: What wears out first?

I would think you stash of ammo would be the first thing to go :evil:

I keep a spare bolt. I check the headspace (USGI FIELD gage) on that bolt in both our ARs every year. The bolt and barrel extension together determine headspace.

The TM advises against changing bolts without checking headspace. Given the marginal quality of some AR part suppliers, it's cheap insurance.

BSW

With the spare bolt, do you just need to check headspace with a go/no go headspace gauge?

Generally headspace on an AR is set when the barrel extension is installed. IF the barrel extension was installed correctly and IF the bolt is in-spec, then you do not need to check headspace.

Having said that, I've seen (once in about 15 years) a new bolt in a new barrel fail a headspace check. My personal practice is to check the spare with the barrel in question when I first buy it. After that I do not worry about it as long as the bolt has not been used long-term in another rifle.

The reason the military warns against swapping bolts in ARs is that if you take AR #1 with unknown number of rounds and no log book documenting wear and then put that bolt in AR #2 with unknown number of rounds and no log book documenting wear, it is a lot easier to get an excess headspace situation. They are less worried about a new bolt in an older rifle than they are about armorers mixing and matching used parts.

i beat the living crap out of mine while on tour and spit out well over a thousand rounds without choking (thanks to mill-comm). they VERY RARELY break down. the only thing i can recommend is an extractor spring, or gas rings, those are the only things ive seen need replacing in the past 10 years of handling those weapons.

I replace the gas rings and extractor and its pin at 2K rounds just on principle. I also run a D-fender as mine is an M4gery carbine. Will probably invest in a set of headspace gauges and a spare MPI'd bolt carrier group down the road--but that is probably overdoing it a bit.

Until something in the BCG breaks.

I've been shooting & buying guns for more than 20 years and I have yet to wear one out...I say worry about your ammo budget wearing out before your guns :cool:

Mine wears out my trigger finger & my ammo budget faster than anything else. It's also worn-out several local coyotes. Past that?

Gas Rings...like Dienekes said.

Parts most likely to wear out are the gas rings, firing pin retaining pin, extractor spring, extractor,firing pin, ejector spring, and eventual bolt failure in that order.
The disconnector, hammer and trigger springs are the next most likely failure parts.
You can minimize wear by installing upgraded parts such as a McFarland one piece gas ring, and chrome silicone ejector and extractor springs and will allow these parts to last as long as the service life of the bolt.
Chrome silicone hammer group springs increase serviceable life to these parts also.
There will still be the risk of the extractor chipping out.
Not using the firing pin as an improvised pin punch will also increase the life of this part.
The firing pin retaining pin usually fails because it bocomes distorted from repeated diassembly and installation to the point it will no longer fully seat in the through hole.

Because there is no heat transfer to the action spring,(buffer spring), these tend to last for tens of thousands of cycles.
In other words, they very rarely wear out unless they break for some reason.

The firing pin retaining pin (looks like a cotter pin) has shown the most rapid wear of any part on all the AR's I've operated.

Fortunately, they only cost a buck (or less). So there is no excuse for running a worn out retaining pin.

My plan (still in implementation phase) is to keep a spare bolt in the MIAD grip of each lower I have. That way, no matter what happens I will have a spare bolt on hand.

Right now I have one MIAD grip, one spare bolt, and no core to keep it in. But I'm getting around to it. :)

Mike

I'd keep a spare bolt, cam pin, firing pin retaining pin, buffer spring, set of gas rings, extractor spring and o/ring, and a spare bolt in a parts kit. Should cover just about everything.

Excelent answers. The question was asked to me by a friend of mine that is as new to ar's as I am (very) and I figured you guys would have a good answer, which you did. The question was asked more as a "just incase" scenario, not necesarily as a "I'm worried about it breaking" sort of thing. I get the feeling that a spare bolt is the best way to be prepared in the unlikely event that something does fail when a spare part is needed yesterday.

I would think you stash of ammo would be the first thing to go
My dillon will be worn down to sheet metal before that happens ;)

So when do these parts wear out and break? I'm close to 10K, with minimal cleaning, and no breakage of anything yet.

Under the kind of shooting us normal guys will do you shouldn't have anything wear out for many years.

I think more people lose parts than wear them out on AR's

I keep a couple of extra pins to hold the extractor and a few extra springs form the lower. I've never had to use any of them.

yeah really. i mean, i don't know why my local dealership has 6 full-time mechanics. MY truck has 20,000 miles on it and nothing's broken on it. all i've done is an oil change. heck, you don't even need a warranty.

Here's a pretty informative thread over at AR15.com about AR-15 parts breakage, with lots of input from Pat Rogers: http://www.ar15.com/forums/topic.html?b=3&f=118&t=360169

Keep the gas tubes clean and stuff. mm

You do not need to clean the gas tube of an AR-15. Putting solvents, oils or pipe cleaners into the gas tube will cause more problems than it will solve.


Some feel free to chime in if they have ever experienced a malfunction because of a dirty gas tube.

Just keep an entire spare BCG on hand; it contains just about every part that could possibly break and be easily field repairable, except possibly the charging handle, which I've heard reports of breaking from time to time.

If its going to be a range gun, honestly, I wouldn't even worry about it. The chances of a quality part just breaking within several thousand rounds is very low.

Dirty ammo and grimy crappy gas tubes are bad, no?
I didn't say use a solvent to uberclean the thing.
just run a little fuzzy pipe cleaner down the thing every once and a while
to make sure it's clear. they are fairly small compared to more
durable rifles like the sks.
You will find that ammo like wolf, that often burns extremely dirty is like high a cholesterol diet for someone with narrow arteries.
All you have to do is give it a looksee to make sure it's not getting too dirty.

Common wisdom goes that the 20,000 psi entering the gas tube is going to clear out any blockage a lot more effectively than a pipe cleaner. The AR gas tube is self-cleaning.

The last time I cleaned an AR gas tube was with about 100 rounds through my first AR. I then received the advice above, haven't cleaned one since, and never had a problem so far.

hey, thanks for posting that link, dirkster.

Stag Arms as a spares kit for $32 that you might look at.

http://store.stagarms.com/catalog/product_info.php?cPath=26&products_id=52&osCsid=d0dcec556bac033ef16a755aae64e80d

I'm not a high speed guy, but I'm definately not a "normal" shooter. I've had several 1K plus days. I don't clean it often, just keep it lubed. I've never put anything in the gas tube. The gun runs fine anyways. I really don't believe you need to swap any part every 2K rounds. I do believe the bolt will be the first thing to break, but I figured it would have went by now. I think some people get a little too worked up over maintenance that isn't needed for a long time.

What wears out first? Your ammo, and your patience with rising gun prices.

Your billfold!:D

Good thread Dirkster. Thanks for sharing it.

Dirty ammo and grimy crappy gas tubes are bad, no?
I didn't say use a solvent to uberclean the thing.
just run a little fuzzy pipe cleaner down the thing every once and a while

I've been told more than once that the gas tube is self cleaning (the rest of the rifle is most certainly not, though), and that shoving a pipe cleaner down the tube is more likely to result in a broken pipe cleaner blocking the tube. That will take the rifle out of action...

Hey, Bartholomew, can you add this thread to the rifle reading library?

Hey, Bartholomew, can you add this thread to the rifle reading library?

Good suggestion. I have always agreed with the common wisdom ny32182 suggests. I have never personally seen a rifle malfunction from a dirty gas tube; but I have seen rifles with pipecleaners or q-tips jammed in the gas tube.

On firing pin retaining pins, they do get bent out of shape sometimes and I agree they are a handy thing to keep around, particularly if you use an unshrouded bolt carrier. On the shrouded carriers they rarely need replacement; but the part does get lost.

barrel

extractor spring
extractor