AR Sponsor
Posted: 4/14/2009 6:26:00 PM EDT
| The ole girl is getting up in age and I have already had to replace the buffer spring, and am now wondering what else needs to be replaced soon. Anyone have a tentative mileage maintenance list for springs all around the gun a la a car manual? If I recall correctly, there is a .mil armorer's book on service life on springs and other parts. |
|
Quoted:
Quoted:
I've never seen a schedule based off round count, only off condition. Do you happen to have that floating around? Check the -23&P. http://www.ar15.com/content/manuals/TM9-1005-319-23.pdf |
|
AR-15 CS Ejector and Extractor springs
Also, on page 89 of the "Black Rifle II" is a chart titled "Malfunctions and Unserviceable Parts Permitted in 6,000 Rounds" that lists the Minimum Life Rounds for the ejector spring as 3,000 and 2,000 Minimum Life Rounds for the Extractor spring |
|
Spring weaken with the number of times they are cycled, the length of time they are compressed or if they suffer damage, i.e. kinking/bending/surface gouges, nicks/corrosion.
In application other than firearms, the only true test of a spring I am aware of, is too measure it in a tool that measures the force to compress the spring. You look for the force gradient and the force to compress it to distances it will operate at. Even then, depending on application, if it passes the test, if there are signs of damage that might later cause the spring to fail, its replaced. I'm NOT an expert on the TM, obviously it is wise to do the test in the TM, replace the springs if they fail tests in TM. But I've seen more than one reference in the TM that is a little subjective, replace a weak or broken spring. What determines if its weak? Obviously, if a function of the weapon that is directly effected by the spring is slower or malfunctioning, its weak. Do you have to wait until your weapon malfunctions before replacing a spring? The tools to properly test the various springs would cost more than all the springs total, many times over. If someone is so inclined to replace springs based on a round count, I really don't think there is anything wrong with that, as long as they understand they may be throwing out a spring that has half its life left in it, if they are willing to spend the money and time to do it, to make sure their weapon is in tip top shape, that's their choice. At the same time, there is nothing wrong with someone that doesn't want to waste the time and money, they don't mind having a few malfunctions on the range, to discover the weak spring, order the part and fix it, there is nothing wrong with that either. Its the same debate about the oil change intervals in cars. Yes, people changing oil every 3k miles, half the time are throwing out oil that is only half way through its life. The people changing oil every 6k miles, half the time are running on worn out oil. Yes, that's a simplification, you have to factor conditions and usage, etc, but its an example to make a point. Doing oil analysis will cost as much as an oil change for most passenger cars, not much of a mediation measure, unless you have a big truck with a 15 gallon oil pan. Like owning spring testing tools, unless you have hundreds of AR's to test. You have to decide if you want to do overkill for preventative maintenance, or the absolute minimum or somewhere in between; as well, if it is worth the extra cost and effort OR NOT. It will vary from person to person. |
AR Sponsor