2,500 rounds:
- Inspect the extractor spring and insert, and replace as necessary,
5,000 rounds:
- Replace extractor spring
- Replace extractor insert
- Replace Crane O-ring (if present)
- Replace gas rings
- Replace buffer spring
I use springs from Sprinco. https://sprinco.com/. They have a selection of AR-specific springs.
10,000 rounds:
- Replace bolt
15,000 rounds:
- Replace barrel
The “Replace” intervals are automatic. Even if the part looks decent, I replace it. Of course, I inspect all these parts anytime I clean or have the weapon apart; if a part needs replaced earlier, I do so.
During cleaning, check the following:
- Extractor, especially the groove, for wear or cracking, edge should be sharp
- Bolt lugs for peening and chips
- Gas key is straight and opening for the gas tube is round and smooth. It is tight and screws aren’t loose. If you have a reverse torque wrench, you can check the screws at 20 and then 30 inch/lbs, but no further.
- Check bolt carrier body for cracks, especially around the cam pin hole.
- Firing pin tip should be smooth and rounded; no dents, chips, or weirdness.
- Gas rings are whole and not broken. To test for wear, grab your assembled BCG. Pull the bolt out of the carrier as far as it will go. Stand the bolt and carrier up on a flat surface, with the bolt face down. If the carrier doesn’t start to slip down, you’re good to go. If it does, your gas rings are worn. Get some new ones. If you have a McFarland-style gas ring, this test won’t work.
- Look down in your lower and make sure that no debris, like metal shavings or primers, have fallen in there and gotten lodged.
- Inspect buffer for peening; it should be smooth. Wipe the crud out of your receiver extension tube (“buffer tube”), lots of folks don’t do that. If the “sproing” bothers you, wipe some grease in the tube and on the outside of the buffer spring.
- Check your magazines to make sure they aren’t full of sand, dirt, and general crud. If you use metal magazines, check the feed lips to see if they’re starting to spread. On all magazines, regardless of material, check the backs of the feed lips for cracking.
- Check to ensure that optics, lights, BUIS, muzzle devices, sling mounts, etc., are gut und tight. Can’t count how many times during a class that a student has had accessories fall of their weapon.
-O-rings and seals. Inspect them for tears. Wipe them clean. Grit bearing against the O-rings when tightening or loosening a part will wear and tear them up. Lube lightly with a silicon-based, non-petroleum lube. Super Lube makes a product called O-Ring Silicone Lubricant that is perfect. Where will you find O-rings in your weapon systems? Lights, optics, and any device that uses batteries. Why lube the seals? Helps maintain the integrity of O-rings and other rubber seals. Helps keep moisture out. Moisture can corrode batteries, contacts, and other internal parts.
Semper Fi!
- Inspect the extractor spring and insert, and replace as necessary,
5,000 rounds:
- Replace extractor spring
- Replace extractor insert
- Replace Crane O-ring (if present)
- Replace gas rings
- Replace buffer spring
I use springs from Sprinco. https://sprinco.com/. They have a selection of AR-specific springs.
10,000 rounds:
- Replace bolt
15,000 rounds:
- Replace barrel
The “Replace” intervals are automatic. Even if the part looks decent, I replace it. Of course, I inspect all these parts anytime I clean or have the weapon apart; if a part needs replaced earlier, I do so.
During cleaning, check the following:
- Extractor, especially the groove, for wear or cracking, edge should be sharp
- Bolt lugs for peening and chips
- Gas key is straight and opening for the gas tube is round and smooth. It is tight and screws aren’t loose. If you have a reverse torque wrench, you can check the screws at 20 and then 30 inch/lbs, but no further.
- Check bolt carrier body for cracks, especially around the cam pin hole.
- Firing pin tip should be smooth and rounded; no dents, chips, or weirdness.
- Gas rings are whole and not broken. To test for wear, grab your assembled BCG. Pull the bolt out of the carrier as far as it will go. Stand the bolt and carrier up on a flat surface, with the bolt face down. If the carrier doesn’t start to slip down, you’re good to go. If it does, your gas rings are worn. Get some new ones. If you have a McFarland-style gas ring, this test won’t work.
- Look down in your lower and make sure that no debris, like metal shavings or primers, have fallen in there and gotten lodged.
- Inspect buffer for peening; it should be smooth. Wipe the crud out of your receiver extension tube (“buffer tube”), lots of folks don’t do that. If the “sproing” bothers you, wipe some grease in the tube and on the outside of the buffer spring.
- Check your magazines to make sure they aren’t full of sand, dirt, and general crud. If you use metal magazines, check the feed lips to see if they’re starting to spread. On all magazines, regardless of material, check the backs of the feed lips for cracking.
- Check to ensure that optics, lights, BUIS, muzzle devices, sling mounts, etc., are gut und tight. Can’t count how many times during a class that a student has had accessories fall of their weapon.
-O-rings and seals. Inspect them for tears. Wipe them clean. Grit bearing against the O-rings when tightening or loosening a part will wear and tear them up. Lube lightly with a silicon-based, non-petroleum lube. Super Lube makes a product called O-Ring Silicone Lubricant that is perfect. Where will you find O-rings in your weapon systems? Lights, optics, and any device that uses batteries. Why lube the seals? Helps maintain the integrity of O-rings and other rubber seals. Helps keep moisture out. Moisture can corrode batteries, contacts, and other internal parts.
Semper Fi!
