Another dead horse, AR tuning.

[VargmatII]

I know, its been talked to death. But I am still curious.

I have a AR build with a lot of Mk12 flavour, with 18" barrel, rifle lenght gas and an AEM5 suppressor.
So far I have used a standard carbin spring and a H2 buffer.

But last week I got myself a Schmeisser multi wire buffer spring, which is a bit like the Geissele mg42 but with 2 strands of wire and compatible with regular mil-spec type buffers. The multi wire spring is a bit stiffer than the carbin spring. Some say that a stiffer spring with a light buffer is better for function. Others seems to prefer to add weight with a heavier than normal buffer. I did some testing the other day at the range.

I tried the multi wire wring with a carbin buffer, recoil was light but also snappy, at least that is how I would describe it. Ejection pattern was at 14-14:30.

Then I switched over to the H2 buffer and multi wire spring, a bit more recoil was felt but it also felt more controlled, more of a push. Ejection pattern was at 15:00.

What would you run?
I have thought about getting a H3 buffer but I am not sure it is worth the money.
I am not switching to an adjustable gas block.

 

[Clayman]

Vltor A5H2 or H3 with a springco green is what I run on almost everything.

I've found it to be the smoothest and most consistent set up.

I have or had Geissele, jp scs, tubbs, milspec, etc

 

[keenedge]

^Same. Tried many combinations, but now this is the easy button setup I use in all rifles, including 5.56 and 6.5G.

 

[Cascade Hemi]

AGB or spec port with carbine buffer and +10% spring.

 

[RTH1800]

You ruled out the best option to tune your rifle. Difficult to help you.

 

[hlee]

Just buy all of the buffers and all of the springs. Mix and match until you find the best combination for your setup. Shouldn’t take more that a few sessions and a couple of cases of ammo.

Or get an adjustable gas block, and spend 10 minutes at the range with about a box of ammo.

Both methods will work.

 

[TonyAngel]

Man, lots of guys get all wrapped up in the ejection pattern. Assuming that your extractor, ejector and related springs and inserts are in spec, the ejection pattern is supposed to be indicative of your closed bolt lock time.

Buffer weight is the easiest way to tune for closed bolt lock time, but going with a heavier spring has little to no effect on the closed bolt lock time, although it does alter the ejection pattern.

The only reason to use a heavier spring is for increased reliability of feeding when the rifle gets dirty and starts to dry out.

Assuming that you aren't running an adjustable gas block and that you're getting something around a 3:00 ejection pattern with the heavier spring and H2 buffer, id leave it at that.

The H2 buffer is usually a good weight providing sufficient closed bolt lock time and the slightly heavier spring will help to ensure feeding in adverse conditions.

Not to be presumptuous, but for those that don't know, when a rifle is referred to as being overgassed, what is usually meant is that the rifle is exhibiting signs of having an insufficient closed bolt lock time. Increasing buffer weight increases closed bolt lock time. Spring rate affects bolt velocity.

 

[thedude824]

In my DI 556 guns without AGB or suppressor I would run the Vltor A5H3 and Sprinco green. As others mentioned.. easy as it gets.