Buffers...I’m confused

[HanzMcFeely]

The LR308 build I finished up came with a Bushmaster 6 position carbine length tube/buffer/spring. Can’t seem to find any info on what this stock buffer weighs.

I picked up an odinworks adjustable buffer to install to help mitigate recoil. Now I’m second guessing it. Will it work and what should I set the starting weight at? Their chart on the website makes it even more confusing...

[HanzMcFeely]

Digging deeper:

Pulled buffer/spring back out and measured. It looks like it may be a bushmaster AR15 carbine set that CDNN included with this build kit.

Buffer measures 3.25”, spring measures 28/29 coils @ 11.5”, and the tube is 7.25”. If I can find a scale I’ll weigh the buffer

Looks like I may need to order a longer buffer tube and/or spring to go with the odinworks. And more weights.

The problem I’m finding is that with an empty mag inserted, the bolt will lock up on the back of the mag instead of at the bolt catch. Mag out and it locks up fine.

[Emptymag]

Longer buffer tube? Is that a real thing?

I don't know dick about 308 ARs, but thought they used the same tube as an AR15.

[HanzMcFeely]

Longer buffer tube? Is that a real thing?

I don't know dick about 308 ARs, but thought they used the same tube as an AR15.

Digging around online, from what I’ve read the armalite ar10 tube is longer.

[RRHemi]

DPMS platform LR 308's use a standard AR 15 buffer tube. I believe the buffer is shorter to accommodate a longer BCG. I just use those Buffers and tune with an adjustable gas block if needed. The spare springs I have bought are 308 specific.

[P89]

I ended up switching out springs and focusing less on the buffer weight (h3) to get the .458 to run right.
https://stratusarmament.com/product/...uffer-springs/

[HanzMcFeely]

DPMS platform LR 308's use a standard AR 15 buffer tube. I believe the buffer is shorter to accommodate a longer BCG. I just use those Buffers and tune with an adjustable gas block if needed. The spare springs I have bought are 308 specific.

That’s what I’m reading, and that the spring is 308 specific as well.

According to the chart at heavybuffers.com though, I may actually have an AR15 buffer.

[RRHemi]

That*s what I*m reading, and that the spring is 308 specific as well.

According to the chart at heavybuffers.com though, I may actually have an AR15 buffer.

My 308 Buffers are def shorter.

[HanzMcFeely]

My 308 Buffers are def shorter.

Researching it, the 308 buffer is supposed to be something like 1/2” shorter than the AR15 buffer.

I’m wondering if CDNN just packaged this kit with the wrong buffer. I may be able to get away with throwing the odinworks one in with this spring, but will probably need more weights from them. Everything I’m reading online suggests that anything lighter than an H3 buffer in 308 is a bad thing and the standard odinworks kit is something like 4.65 oz vs H3 buffer at 5.4 oz. lighter buffer will increase recoil, correct?

The chart at heavybuffers recommends 6.5oz for most 308 carbine length setups

Edit: weight of the carbine buffer that came in at 3.803oz, which matches up with H carbine style listed

[RRHemi]

Researching it, the 308 buffer is supposed to be something like 1/2* shorter than the AR15 buffer.

I*m wondering if CDNN just packaged this kit with the wrong buffer. I may be able to get away with throwing the odinworks one in with this spring, but will probably need more weights from them. Everything I*m reading online suggests that anything lighter than an H3 buffer in 308 is a bad thing and the standard odinworks kit is something like 4.65 oz vs H3 buffer at 5.4 oz. lighter buffer will increase recoil, correct?

The chart at heavybuffers recommends 6.5oz for most 308 carbine length setups

Edit: weight of the carbine buffer that came in at 3.803oz, which matches up with H carbine style listed

Sounds like CDNN did exactly what you suggest. That big BCG bottoming out could be an issue!