AR Preventive Maintenance

[D.Hayden]

How often do you (not should you), replace parts before they break?

• Bolt gas rings
  
• Extractor Spring
  
• Ejector Spring
  
• Firing Pin Retainer Pin
  
• Others?
  

I have parts (gas rings, extractor spring) on hand, ordered just for this purpose.

I know I should, but since it's running 100% - should I do it anyway?

Thanks... "Causing more harm than good" .. Dave

[Dan Sierpina]

I'm a proponent of if it ain't broke, don't fix it. My firing pin retainer was bent, and it was old. That got changed. If you have extraction and ejection problems, change those parts. If not, why change them? Clean and lube it, and fix if broken.

[Scout454]

As a rule of thumb:

* Bolt gas rings When the bolt begins to move easily in the carrier (i.e., little or no tension). I prefer McFarland 1 piece rings

* Extractor Spring When it looks noticabally shorter - or I have extraction problems. I do use a D ring too.

* Ejector Spring Same as the extractor spring sans d Ring

* Firing Pin Retainer Pin When it's obviously worn. They're cheap.

* Others?

[TRUBL]

Clean it once a year.....whether it needs it or not!!! Kinda like bath time.

Actually.....everytime you do clean the bolt assy(which should be way more than once a year) inspect all the parts....visual is fine for the most part, and replace as needed. The part you may (key word...may) replace the most is the cotter key that holds the firing pin in place. On the military weapons, there is a rumor that somewhere around 6000 rounds the bolt and key should be replaced as they tend to micro fracture....but that is on a full auto weapon, not a semi. Ejector and Extractor springs would probably be the next most replaced part. But, typically, you'll get 1000's of rounds out of the parts before any real attention is needed. As cheap as they are.....I'd consider having a back up bolt, some springs, cotter pins, maybe a firing pin if you are really concerned, or heck, you may even want to consider a complete bolt carrier assy. I hate takin apart a rifle completely apart at a match as if anything is NOT going to go back together right, it will be THAT day.

FYI......bent retaining pins (cotter pin) can be bent straight too, done that. BUT again they are cheap enough to have spares, if you are so inclined.

Tim

[Merlin Orr]

Per the way I was taught by my AR mentor.....After every match my gun gets the full house clean and inspect. Chamber brushing and clean and decopper barrel. Complete bolt assembly, carbon cleaning/scraping inside bolt carrier, tear down bolt and extractor assembly to check spring and for pieces of copper inside assembly. Oil and reassemble. When the bolt moves easily inside the carrier its new rings... A new gas tube every few thousand rounds..needed or not.

Overkill... Maybe. My gun has never once - not one time - failed to go bang when I pulled the trigger.

[Dan Sierpina]

Per the way I was taught by my AR mentor.....After every match my gun gets the full house clean and inspect. Chamber brushing and clean and decopper barrel. Complete bolt assembly, carbon cleaning/scraping inside bolt carrier, tear down bolt and extractor assembly to check spring and for pieces of copper inside assembly. Oil and reassemble. When the bolt moves easily inside the carrier its new rings... A new gas tube every few thousand rounds..needed or not.

Overkill... Maybe. My gun has never once - not one time - failed to go bang when I pulled the trigger.

You just jinxed it!

[fastshooter03]

Thread drift--It's been stated before but you need to be careful when using McFarland 1 pc rings. I had an issue of gas bleeding past the ring last year with a Les Baer bolt and Young carrier before I decided to do a full dimensional inspection of the rings and the bolt carriers.

The rings can vary in diameter from .498-.503" !

Bolt carriers I've measured are .500-.503"

So if you're unlucky enough to get a small ring in a large carrier, you'll probably have problems like I was.

Everything is better now that I matched them up but if you don't have access to gage pins or small hole measuring equipment, you'd better be using the biggest diameter ring you can find which may mean buying a lot more than one. Or just use the original 3-pc rings which I've seen at least 2 different variations of design.

How often you change your small parts depends on how many rounds you go through and how hot those rounds are.

After every time you go the range and use it(except for prematch sight-in and match time), the chamber and barrel should be cleaned and decoppered. The bolt and carrier should be at least inspected for bits of brass and crap that can get into the ejector and extractor and cam area. Check for extactor tension while you're there. I don't think I've changed anything but rings and extractor springs in years.

Nick

[mpeltier]

+1 Merlin. Thats what I do except the gas tube replacement. I probably should change that out though. Its probably more important for those of us shooting adjustable gas. The only gas tube I have witnessed a gas tube failure on was a friend of mine whose gas tube broke where the adjustment screw enters the tube in the gas block. My theory is that a minute amount of flame cutting may take place where the gas is restricted and eventually a failure can occur. or maybe it was just a freek occurance.

[uscbigdawg]

Dave,

On those small parts, I keep extras in the bag, but every year is not a bad thing, even if it doesn't need it. All of those together is less than $20-30 and it's cheap insurance.

Some preferences are standard gas rings over the 1 piece and on the extractor spring, I get mine from Specialized Armament. They have a beefed up spring that will hold up forever (that I still replace every year).

Rich

[NC Shooter]

$.02 opinion from a Highpower shooter. Do not use one piece bolt rings! I got this from a Marine Corp armorer. He also said, that with the bolt extended as if you were about to install it in the rifle, stand your bolt/carrier assembly upright on the bolt face on a flat surface there should be no slippage. If the bolt slips into the carrier from just the weight of the carrier standing above it, it is time to replace the rings.

Ken

[kurtm]

Stand the bolt on end?? Oh I get it! Now would that test be valid for an aluminum carrier? Titanium? Lightened Stainless? I would be interested in what the Marine Corp would say about those , I know what the High Power guys say!!

[M118LR]

I take my AR apart after about 500 rounds and I do a good cleaning of the chamber, barrel and bolt. I also make a good check of all the parts in the bolt and bolt carrier. Then lube everything and put back togther. Replace parts when needed.

[bigbrowndog]

Kurt, it means your gas rings will last longer with a lighter carrier, yet another benefit of lighter carriers.

I do recall that being the standard, when all carriers were standard, though.

Trapr

[Revopop]

I know I've read to stand the bolt carrier on end to check the rings in an article written by our own Patrick Sweeney.

[NC Shooter]

Stand the bolt on end?? Oh I get it! Now would that test be valid for an aluminum carrier? Titanium? Lightened Stainless? I would be interested in what the Marine Corp would say about those , I know what the High Power guys say!!

Sure, the test is still valid. All you need to do is stack a few wheel weights on top to approximate the weight of a standard carrier. Better yet silver solder the extra weight to your titanium carrier.

Edited May 19, 2008 by NC Shooter