Daniel Defense Carbine Buffer Spring

Product Description

The Daniel Defense Carbine Buffer Spring is a 1.6 oz replacement buffer spring for use in M4-type receiver extension tubes, measuring 0.93 in. outside diameter and 10.25 in. overall length.

The buffer spring is the cheapest part in an AR’s recoil system and the one most often left in place for the life of the rifle. It works on every shot, and over thousands of rounds it takes a permanent set. A shortened, tired spring returns the carrier to battery with less authority, which shows up as the last two rounds not feeding cleanly or a bolt that stops just short of lockup when the gun is dirty.

Length is the fitment fact that matters. At 10.25 in. this is a carbine spring, cut to work in the carbine-length tube behind a collapsible stock. A rifle-length spring in a carbine tube coil-binds; a carbine spring in a rifle tube is too short to do its job.

Key Facts

• Brand: Daniel Defense
• Model: Carbine Buffer Spring
• Manufacturer Part Number / SKU: 15-024-16146
• Outside diameter: 0.93 in.
• Overall length: 10.25 in.
• Weight: 1.6 oz
• Fitment: for use in M4-type receiver extension tubes

When to change a buffer spring

Pull the spring, lay it next to a tape and compare it against 10.25 in. If it has lost length, replace it. It is also worth fitting a fresh spring whenever you change buffer weight, because a tired spring will make a heavier buffer look like the wrong choice when the real problem was the spring all along. Related parts are in our buffers and buffer tube kits and lower parts sections, and the rest of the line is under Daniel Defense products.

Ordering from Western Sport in Roanoke, TX

Western Sport, Roanoke, Texas – licensed FFL/SOT since 2007 and a Daniel Defense master dealer. Springs are on backorder; call 817-393-4000 and we will get one on order for you, and our on-site gunsmith will happily measure your old spring against a new one if you bring the rifle in.

Frequently Asked Questions

Q: What are the spring’s dimensions?

A: Outside diameter is 0.93 in. and overall length is 10.25 in., at a weight of 1.6 oz. Those two dimensions are what decide whether a spring belongs in a carbine tube: a rifle-length spring is considerably longer and will not compress correctly in a carbine receiver extension.

Q: Which receiver extensions does it fit?

A: It is for use in M4-type receiver extension tubes, the standard carbine-length buffer tube on most AR-15 and M4-pattern rifles and pistols. If your rifle has a fixed A2 stock over a rifle-length extension, this is the wrong spring – that tube needs a longer rifle spring.

Q: How do I know my buffer spring is worn out?

A: Measure it. A carbine spring that has taken on a permanent set will be noticeably shorter than the 10.25 in. it started at, and a short spring shows up as sluggish return to battery, failures to feed the last rounds, or a bolt that will not quite lock up on a dirty gun.

Q: Will it work with an H or H3 buffer?

A: A carbine buffer spring and a carbine buffer are a matched pair by length, so a standard, H or H3 carbine buffer all run on a carbine spring. What changes with a heavier buffer is total reciprocating mass, not spring length.

Q: Should I replace the spring at the same time as the buffer?

A: If the rifle has a lot of rounds on it and you have never touched the spring, yes – it is the cheapest part in the recoil system and it has been working on every shot. If you are tuning a cycling problem, change the buffer first and the spring second so you can isolate the effect.

Q: Is this a flat-wire or a coiled spring?

A: We publish the dimensions and weight we can verify for this part number – 0.93 in. outside diameter, 10.25 in. long, 1.6 oz – and we will not characterise the wire form beyond that. Call 817-393-4000 if the spring type matters for your build and we will confirm it.

Additional information