Heavier spring or heavier buffer: which is better?

[dorchester]

My BCM 14.5 carbine length upper functions with .223 pressure ammo either with a standard strength blue CS action spring and an H1 buffer OR with a Tubbs flat wire CS spring and a carbine weight buffer. I'm trying to determine if there is an inherent advantage to either combination. They both work with a wide range of ammo as far as my subjective testing goes, so which should I set as the standard configuration for this carbine? Without real instrumentation, I'm at the coin toss point. Unless someone can give me an insight to the two combinations I might be missing. Thanks.

[Robb Jensen]

The BCM with a standard rate spring and a H buffer will run just fine. If you'll be shooting lots of 5.56mm NATO pressure ammo and/or suppressed a lot I'd recommend a H2 buffer for use with a CAR gas gun.

I don't see the need for extra power springs but then again I'm just weird.

[dorchester]

Hey, I've learned a lot from your posts (mostly weird stuff, though). Seriously, I like the point that the Tubbs spring is supposed to act more like the longer rifle spring rather than that it is stronger than normal. I just don't know if it's true or even significant. This carbine will not be suppressed and I would like it to be tolerant of 75gr 5.56 through 55gr .223 loads. All this while being as soft shooting as possible while running the 75gr 5.56. I know, I don't want much.

[LonghunterCO]

Could I ask the same question? On the buffer anyway, for a Midlength gas 16" upper (BCM of course).

[BufordTJustice]

I have a buddy who just purchased a BCM 14.5" carbine (w/ A2x FH). He runs an H3 w/ Springco Blue std power buffer spring. However, he uses a well worn BCG (the bearing surfaces are pretty smooth) and he also uses a Fail Zero coated hammer (to further reduce friction). His gun runs great.

W/ a normal buffer spring, an H2 should be great for you if you run lots of milspec ammo, as GotM4 stated.

In my 16" BCM middy, I run a Fail Zero (Spike's version) BCG, and trigger group, FSC556, Red Springco XP CS buffer spring, and H3 buffer.

Gun runs like stink even after 200 rds of tula .223.

Unless you're running a coated BCG and hammer to reduce friction, an H2 and std power buffer spring would work well in a 16" middy.

The Tubbs, which I also have used in this setup...feels much more like the std buffer spring than it does the springco red spring. Both worked well for me.

Bottom line, every gun is different and if you're willing to tinker (i.e. buy thing you may never use), going with the heaviest buffer and spring setup that your gun will run (i.e. properly function and lock back on empty) seems to be beneficial. Mine runs amazing....but YMMV.

[The_Hammer_Man]

I have a similar setup, 14.5" BCM w/FSC556, and it eats pretty much anything I give it as long as its reasonably close to MILSPEC.

I have two different spring/buffer setups,

One for light/less than milspec pressure loads,

Second for heavy bullet/high pressure loads like milspec 77grainers.


Normal/light= CS Blue Carbine Spring w/ H-buffer

Heavy= Tubbs w/either a normal buffer or one of the H's depending on bullet weight and pressure charge. Some will cycle with one but not the other.

As the previous poster stated.. tinker.

[Sparky5019]

From my experience and knowledge of physics (admittedly limited); if I wanted to prolong the recoil impulse or keep the breech locked closed for a longer time, I would use an extra power spring (like a Tactical Springs Red) rather than add to the reciprocating mass in the action...but like Robb, I'm weird in my own way too!

Sparky

[dorchester]

As a couple of posters have noted: tinker. Which I have, quite a lot, the carbine works well with either combo and with the wide range of cartridges I desire. It looks like there is no "book" answer to this one. Heads or tails, the lady or the tiger.

[markm]

Those junky aftermarket springs have no place in any of my guns. Definitely dial the weapon in with the buffer, NOT the spring.

[ucrt]

Those junky aftermarket springs have no place in any of my guns. Definitely dial the weapon in with the buffer, NOT the spring.

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MarkM,
That's my understanding.

A quality AR maker's rep told me this past Wednesday, that the slower the BCG moves the better, (Which is still going to be pretty fast) and the Buffer controls the speed. He said a heavy spring has no place in a functioning gun, especially a factory "tuned" one.

He told me they got a gun back last month under warranty that the guy claimed wasn't reliable. Once the gun is in the shop, they see a heavier spring was installed. They call and confront the guy and he says, "It is a "better" spring than the one that was in the gun!" They asked him if the gun worked with the original spring and tells them, "Yes, it worked fine but this is a better spring!". Oh well...

I couldn't do that job. I'd have to say, "Well then go ahead and use the "better" spring but just get used to your gun failing...stupid!"

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