What are the fastest wearing parts on an AR?

[CanPopper]

Hi,
Let's say I'm trying to build an AR whose parts can last a long time without breaking. What are the parts I would need to focus on to ensure it maintains its function?

Also, what would be the expected life of:
1. Regular extractor vs chromed extractor or TiNi coated extractor
2. Regular bolt head vs JP Enhanced bolt
3. Bolt Carrier Group

 

[JTinIN]

Re: What are the fastest wearing parts on an AR?

Been shooting full auto with friends for since well before the last AWB and tend to see the carrier key come loose every so often on factory Colt bolt carriers (half dozen cases of ammo or more), but have not had one come loose that I re-staked, but have been shooting the belt guns more the last several years.

For the guys shooting 9mm in the pre ramped bolt days use to go through hammer pins until switched to the stainless steel 9mm ones, which I run all the time.

Even shooting Wolf ammo the extractors tend to last a long time and typically change one or two sets of rings before the extractor (again a dozen or two dozen cases between changes and I take them out before they fail).

Always take with me an extra extractor, extractor spring, plug, #60 o-ring and firing pin to a shoot, typically installed in a complete bolt carrier (which is in turn in the extra upper ;-).

 

[7.62gunr]

Re: What are the fastest wearing parts on an AR?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: JTinIN</div><div class="ubbcode-body">Been shooting full auto with friends for since well before the last AWB and tend to see the carrier key come loose every so often on factory Colt bolt carriers (half dozen cases of ammo or more), but have not had one come loose that I re-staked, but have been shooting the belt guns more the last several years.

For the guys shooting 9mm in the pre ramped bolt days use to go through hammer pins until switched to the stainless steel 9mm ones, which I run all the time.

Even shooting Wolf ammo the extractors tend to last a long time and typically change one or two sets of rings before the extractor (again a dozen or two dozen cases between changes and I take them out before they fail).

Always take with me an extra extractor, extractor spring, plug, #60 o-ring and firing pin to a shoot, typically installed in a complete bolt carrier (which is in turn in the extra upper ;-). </div></div>

Good Lord......that's somebody who goes thru alot of rounds.

 

[harbinger]

Re: What are the fastest wearing parts on an AR?

If you want one to last the longest, go wit milspec parts. It may not be the smoothest or fanciest but they will last for many thousands of rounds without breakage. The gas key mentioned earlier is the part I see fail the most often. If it is not properly staked it will work loose and cause malfunctions, or shear the bolts that hold it in place.

The basic design was built to last and has proven itself time and again for longevity. If I had to plan on parts to wear the most it would probably be gas rings and gas tube, not that I've seen them fail, but they are scheduled maintenance after 8000 or so rounds.

 

[Shooter45]

Re: What are the fastest wearing parts on an AR?

I shoot full auto M4's very often with work and we see the carrier key work loose often on the 10.5" Colts. Never see it with the 14.5" or anything else but the 10.5". I believe it is a staking problem done by the armorers and not a factory problem but it is obviously a staking problem of not being secure enough.
I was just looking yesterday at must have parts in preparation for any type of new regulations that would stop the use or availability of new parts. The only things I realized I needed were:

Gas rings
extra firing pins
extrators with O-ring
Spare trigger group(s)
retainer pin for carrier

These are the only things that I have seen go down in M4's and AR's alike. I shot thousand upon thousands of rounds through my work guns and have never had problems with anything other than the gas rings wearing in. Earlier this year my gas rings were shot and showed now resistance when the bolt carier group was out of the weapons but when shooting, it worked fine for around 1,000 rds before I changed it.
That list would be my recommendations for extra repair parts for anyone and everyone with an AR. Just remember, if you change the bolt you have to headspace it therefore you'll need go and no go gauges. I've never seen the splins sheer off or break on an M4 although I have seen them cracked before but who knows how many thousands of rounds were shot before that happened or the cause.

 

[BCP]

Re: What are the fastest wearing parts on an AR?

Any small part attached to the bolt. Extractor spring o rings etc.

 

[HD1911]

Re: What are the fastest wearing parts on an AR?

USGI Buffer springs tend to go quick for me. Like others have said, a spare extractor, extractor spring/polymer insert/crane o-ring, ejector and ejector spring, firing pin, and may even a spare bolt, are good things to have on hand, for a rainy day.

 

[Shooter45]

Re: What are the fastest wearing parts on an AR?

It's cheaper and more effective to buy a full bolt kit than buying the individual parts. You save a few dollars and get more parts with the complete bolt, if you can find anywhere that has them. Just my recommendation. If a part goes down you use the spare bolt for whatever parts needed, or swap the entire bolt if you have a head space gauge.

 

[stel67]

Re: What are the fastest wearing parts on an AR?

with the price of ammo and the limited availability of said ammo I do not see me wearing out any parts on my guns!

 

[JTinIN]

Re: What are the fastest wearing parts on an AR?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: stel</div><div class="ubbcode-body">with the price of ammo and the limited availability of said ammo I do not see me wearing out any parts on my guns!</div></div>

However, the inverse is also now true during these crazy times, if you wished to replace a bolt carrier now days, there are none around except on the secondary market (i.e. one each from private sales where you find them for what price is being asked).

Would recommend when the crazy times return to normal, that everyone has an extra complete bolt group, however, they tend to then gather an extra upper, which in turn gets an extra lower parts kit, about which time you toss in a lower and a take off stock and darn all your spare parts are now another rifle, thus needing you to start over again ;-)

Checking back and have also see a hammer J spring pop out and a few match type triggers start to misbehave in semi ARs. Thus when going to a larger shoot, in particular out of state and/or for several days, I take the repair bag (tool bag that use to always carry ;-) which includes a smaller nylon bag with a lower parts kit, bolt rebuilt kit with extra new Colt bolt head and head space gauges ... plus an extra upper (really hate being down ;-).

 

[jmtgsx]

Re: What are the fastest wearing parts on an AR?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: JTinIN</div><div class="ubbcode-body">

Would recommend when the crazy times return to normal, that everyone has an extra complete bolt group, however, they tend to then gather an extra upper, which in turn gets an extra lower parts kit, about which time you toss in a lower and a take off stock and darn all your spare parts are now another rifle, thus needing you to start over again ;-)
</div></div>

This has happenned to me recently!
Damn the luck!

 

[Greg Langelius *]

Re: What are the fastest wearing parts on an AR?

I recommend one of these when things slow back down, along with this, and this/

Remember, things don't just wear, some things also get lost.

Greg