It seems that over the past decade some people and companies provide their rifles with H-Buffer as a standard. Considering that H-Buffer origin came from the need of reliable cycling of 14.5" bbl with carbine gas on full auto, why is it the default recommendation for semi auto, often 16" bbl with mid gas vs standard carbine buffer ?

H2 w/ Tubbs?

Pie plate sized GP diameters and Chicrap action springs brought much of it about.

Overgassed barrels, that where the recommendation comes from around here.

Barrel profile also plays a role in the equation.
The heavier the barrel the heavier the buffer (for full auto use)

On semi auto I’ve never had an issue with the standard carbine buffer & I didn’t notice any advantage with heavier buffers on a properly gassed barrel

A fresh carbine spring and a standard buffer fixes almost every properly gassed barrel equipped rifle out there.
Seen so many rifles with a "Super Extra Orange Power Recoil Spring" and some gimmick "Pneumonic" buffer that wouldn't feed, fire, or eject until the this junk was removed.
Now with these "new breed" of barrels "tuned" to fire the crappiest, dirtiest, cheapest steel case crap you can make via "bath tub manufacture" this "junk" has made a comeback.
I am shocked nobody has marketed a buffer/spring combination with a dial on it, with "Wolf" on one end and "Black Hills" on the other.

There are only a couple of brands (DD, Colt, BCM, Triac, BRT, BA's Hanson, PA's line) or individual lines of brands that are gassed properly, so other 80-90% of the market needs them.

95% of buffer recommendation threads are pure bullshit anyway.

OP posts "I have a 16 in barrel with a carbine stock, what buffer should I use?"

Followed by recommendation after recommendation. Most will say H someone who thinks they are cleverer then the rest will say Vltor A5.

Then someone with some knowledge will ask a few simple questions like gas port location, or barrel brand (an attempt to at least get at the reputation for gassing level from the manufacturer if not gas port size).  

Most will assume caliber (which is probably fair), few will ask what type of ammo they run, if they run suppressed.

Someone will chime in with their magical spring/buffer combo knowledge.

Almost nobody will ever ask what they are tuning for (max reliability of softest impulse) Bolt carrier weight (most are full m16 carriers now, but Law folders change the weight).

Few understand things like barrel profile, temperature range, elevation over sea level can have an effect.

Nobody can really know the best buffer weight for somebody else's set up as there are way to many factors.

The OP's in the end just wanted a quick answer and will probably never test it at the edges of the operational envelope anyway.

The real answer, for most reliability, is probably carbine weight.  It is unlikely that your gun is configured in such a way that the gun will beat itself apart with a carbine buffer.  That doesn't mean you get the best performance with carbine weight.

The real practical answer is the heaviest weight that will lock your bolt back on your weakest ammo in your most adverse conditions.  But that requires the OP buying more then one buffer, which they are unlikely to do.

The ar15 is more forgiving then most people give it credit for, if your ejection pattern is 10 degrees different from your buddies it isn't a reason to panic.  If you are trying to squeeze maximum performance, you are going to have to experiment instead of ask on the forum.  While forgiving, there are also many many factors that play into performance and nobody can possibly know the answer.

From my experience, extensive military, and now as a SOT, I have come to the conclusion that most factory built guns come with a carbine buffer just due to cost. Most weapons will benefit from a heavier buffer. I say that because very few barrels are gassed appropriately. Most barrels are over gassed to force cycling. There are a few that gassed correctly, but they are vastly outnumbered by barrels with massive gas ports. More than a heavier buffer, I recommend to people BRT gas tubes that actually cure the issue instead of treating the symptoms

Read every word, and glad I did.

All of that.  

In a semi-auto with an even half assed reasonable port size the buffer almost doesn’t matter.

In a world full of 12.5” mid lengths, they’re going to have to starting making buffers out of carbon fiber at this point.

Have multiple buffers and use the one that still functions with cheap ammo or in the cold. We all want a soft shooting rifle but my trunk gun is a carbine with an H buffer because I know it will still function in the cold and/or with shitty ammo. Not all barrels are created equal, nor are needs of the user. It’s on YOU to make sure your rifle does what it needs to. The buffer just happens to usually be the easiest way to guarantee that.

I don't know about other Colt rifles but my 6933 shipped with an H buffer and I kept it when I swapped out the FSB barrel for a stripped 6933 barrel and MK4 federal handguard. It runs pretty close to perfect.

Too light and it’ll short stroke too. The gas only pushes the carrier back about 1/4” and after that it’s all momentum.

Funny you mention short middies....

I had been eyeing an aero m4e1 in either 12.5 or 14.5, which are middies in which MANY folks have mixed feeling about.... I think its mostly in theory but seems some EARLY BCMS were finicky until the fixed the GP size.

I notice the 14.5 is becoming very popular but many say it being in "Middie" form can make it finicky with ammo and proper cycling compared to the proper carbine gas setup 14.5
(gas block location/dwell time, etc)

Assuming the 12.5 wpuld be prone to more issues in middie form opposed to 14.5 unless the GB location is different (which I doubt)

Why didnt they just use carbine, as its tested and proven???

Would probably be Xtac 55-62 used if gotten, and would prefer whatever can be treated the most similar to 16" as far as ammo, spring/buffer, etc... In a fan of using H but not sure if that would be an issue....

I will note, the Aero springs feel awfully light, my buddy has a 16" standard Aero build and directly out of the box, the spring compression was night and day compared to a Spikes factory spring I suggested him throw in being a spare.

The Spikes felt like an XP spring in comparison.... SUPER stiff and if takes some extra finger strength to fully compress, while the Aero spring compresses without any notable resistance when charging it.

Using the bolt release, that SS Spikes spring slammed home and sounded like it was gonna break the platform. LOL

The Aero even doing a loud PING when dry firing, unless that just now Nitride Carriers do. Kind of turned me off tbh...

Even compared the springs to my Damage Industries CS spring and the Aero was a tad lighter feeling (and the CS spring already feels light but I chalk that to it having a wider diameter and not snaking up in the tube)
yet that Spikes spring was twice as strong (feeling), not sure if they act the same during live fire but the Aero one feels Cheap IMO.

My case and point here is how it was mmentioned that different setups varying per company and parts used. (Specs aswell)

Spikes factory spring feeling like XP spring while Aero springs feel as if they compress with little effort shows things arent the same across the board... Both being factory springs.

Iffy on whether Aeros quality is great for the price similar to the MP sport out there which are said to be awesome; OR if Aero is closer to PSA stuff (hit and miss depending the build)

To me if the questioner has a good barrel then I say keep it standard.  If they have a low end(likely overgassed)  then maybe an H. Finally I use an H2 because I am a lefty and run a can. Try to keep as much gas out of my face as I can.

I always try to run an H2 with a tubs spring and step down from there until it can cycle PMC Bronze 223 55g unsuppressed

I assigned my son a 10.5 to shoot steel case ammo, that is that guns sole purpose in life.

It's a PSA 10.5 A2 upper, Aero M4E1 lower, SOLGW BCG,  Super 42 with H2 buffer, and a YHM Turbo T2.

He and his buddies shoot the piss out of that damn thing, I wish they would break it already since they wont maintain it. They squirt oil in it occasionally and the can is perma-locked.

The lower came with an H buffer, I emailed Aero and asked if that would be the preferred weight and received a reply of "well we had to put something in it."

When BCM became big in the scene over a decade ago, they used to advertise the use of a H buffer with their mid length gas system barrels. Since they have changed the format of their website, they don't seem to have that little blurb in the verbage on the mid length barrels that they sell. When I bought my first BCM 14.5 inch mid length complete upper back in 2010, I ordered a H buffer due to that recommendation on the page that I hit add to cart. All my ARs prior to that were regular carbine gas system and ran standard buffers. But a majority of the people posting on this topic are correct. There are many of different barrel manufacturers with different specs on their products, biggest one being gas port size. I run mostly H buffers in my guns now, especially since I've added a suppressor. Some of the shorter variants with carbine gas length run better with H2 buffers, that's just what I have discovered from my experience and experimentation. I have played around with hydraulic buffers and different weight buffers in competition rifles and have seen the ups and downs of both. At the end of the day, it's what the user finds what is right for them for their "perfect setup".

This.  It seems a lot of people post with out actually shooting the guns in my opinion.  The great thing about the AR system is that you can tune it to your liking - if you like over gassed - have at it, if you want something more balanced, you can do it.  I recently caught a shit ton of flack on the KAC sub-forum or suggesting that an SR15 Mod 1 that I had some issues with could be improved by changes to the buffer and spring (grain of salt with that - they are more rabid than they HK people) but I hope you get the point.  Tune the gun for what works for you.

Because I run short barrels in full auto with suppressors.

Go be poor somewhere else.

Way to bring the class

/thread


I prefer the A5 system for a few reasons:

- more LOP adjustment range and has longer than A2 LOP at max extension.
- uses rifle spring that the AR was designed around
- A5H2 is same weight as rifle buffer and allows 2 weight steps up and 2 weight steps down for tuning IF your barrel isn't properly gassed.

So the H buffer cycled best in a BCM 14.5 Middie?

Was the carbine one just more gassy amd the H tamed it, or did it need an H to actually "function/cycle" better?

Due to the longer dwell time, I figured you may only want to go to H if standard is gassy.

I'm the tyoe to use H automatically btw but so much info on 14.5s being finicky, unless that was in the early days of BCM befire the gas port was (I think) .78

?

Mike Pannone wrote that article about making a DI M4 stupid reliable and part of that was using a heavy buffer. I still do that at times. I also have carbine buffers in several guns. I don't care nearly as much as I used to. I build everything from the ground up now so if I want to control the bolt speed I just use an AGB. YMMV.

I used to put BCM extractor springs, H2 buffers, Sprinco action springs in everything. I never had any issues doing that but I also haven't really had issues without doing it either. I'm kind of at the stage in my AR ownership where I don't really give a fuck about anything except what has been shown to work in my own experience.

@nighttrainnc:

I still use the H buffer with both my BCM mid length 14.5 and 16 inch uppers. I have a 13.7 inch mid length and a 10.3 carbine that I run the H buffer as well. For my 11.5 and one of my other 10.3 I run H2 buffers. In my experience with my guns, the H buffer works best in my mid length gas guns. My carbine length gas guns run better with the H2 and both gas length variants are almost always run suppressed with a Surefire RC2 5.56.

Real simple. Experience, trial and error. Most of these guns are much more alike than not. In the world of mass-produced parts from across the globe, the gp size is but one small consideration. I my experience, with a decent inventory of assorted ARs, I find the H3 to benefit each one. Softens the blow which quickens recovery time for additional shots for the average joe.

Sample size of one, but my 13.9" Hanson does appear to be perfectly gassed.

Isnt Hanson the same as "Ballistic Advantage", which come on the Aero stuff?

Ir is it a certain model of Barrel from them?

If so, I didnt know they made a 13.9, unless indeed a diff company as Ive never seen Aero market a 13.9.....?

Yes, Hanson is a barrel profile that Ballistic Advantage sells. Ballistic Advantage is owned by Aero Precision.

https://www.ballisticadvantage.com/13-9-5-56-ba-hanson-midlength-ar-15-barrel-w-lo-pro-performance-series.html

The H buffer was developed in the mid 1990s. It’s been a thing since then.

SOLGW says that a heavier buffer helps drive the action, assuming you have enough gas drive to get it started, the weight helps feed another round into the chamber reliably. I believe they also say the H3 is too much weight and hard on the gas rings? May be mistaken on that, but swear I heard it from them.

Seems as the quality manufacturers install a H buffer in most situations. I usually install an upgraded spring for the reliability, -longer spring life. Like mentioned in another post, the 20” rifles had a heavier buffer system, and is ridiculously reliable.

Companies installing carbine buffers most likely do it for the cost savings.

Wouldn't doubt they said that. There's others who swear in a normally configured, OTS, AR, H3s destroy the gun. I have zillions of rounds through a number of ARs, all with H3s and 2 with a bit heavier. Never an issue.

Remember that it’s either weight or spring strength or both that’s overcoming the drag of loading and filth in the action on the forward stroke.

ANYONE here ever used a "Spikes Tactical" recoil (stainless steel electro politished 17-7)  spring?

Could use some advice here:

They claim its factory spec (not all factories are equal though) and it feels 2x stronger/ stiffer than an "Aero recoil spring" which feels like a broken in used spring when new.

Wondering if putting a heavier buffer (Like an H) with a light Aero (feeling) spring, does a sprong need to be stronger for an H Buffer?
(This is for a future build plan due to spare small parts)

I HAD an untested H2 installed with a "Damage industries" CS spring in a 16" carbine (with Semi Auto BCG)
THEN put the Spikes Tungsten powder 4.2oz buffer ( halfway between and H and H2 weight wise)
to step it down a tad from a full H2 to not risk short stroking with 223 Bronze.

***Although***
Even though the Damage Industries CS spring has NO XP properties, it DOES have a larger diameter spring that doesn't snake up in the tube and helps prevent bolt bounce,

***
I'm assuming it would be dumb to use an "Anti bolt bounce recoil spring"
with
a "Known for Bolt Bounce- Spikes Buffer"... Yea?

If so, I'll Swap and put H2 back in the gassy carbine with Chrome silicone "Anti Bolt Bounce- large diameter Spring!

THEN

Take the 4.2 oz Spikes (tungsten powder Buffer) and pair it with the stiff ass Spikes spring, for a 16" Spikes Middie and hope that the extra 0.4oz above an H hopefully isnt too heavy for the 16" Spikes middie!

Hell, they may work best together, the bolt probably cannot bounce too much with a standard spring that's so strong!!! (Spikes spring)

My concern just is the 4.2oz Spikes buffer being too heavy for the Middie, just no reciprocating weights in Spikes buffer, could always ditch the Spikes buffer if bolt bounce is very bad and the extra .03...

Mostly would use X-tac 55-62 but may need to make sure things lock back with "Bronze"

How does this sound in theory (as far as them being fully functional having the 2 setups before tested?

Huh. I can’t say I’ve actually used one, but I do have a couple of them, and if anything they’re a bit softer than a normal carbine spring.  In my testing they were comparable to a Sprinco yellow (reduced power). Wire diameter seemed a bit undersized compared to normal too, I figured perhaps as a result of the polishing.

Maybe they’ve changed the specs since the time I bought them?

When in doubt, order a Colt, LMT, or BCM carbine spring and a standard H or H2 buffer and go in peace.

I like the feel of the H buffer with 55gr ammo and H2 with 62-77.

USGI spring /H1 will run reliably in most everything.  

H or H2 in carbine, standard or H in mid length, standard in rifle is where i have stayed. Dependent upon gas port size, ammo, and if you're suppressed. The only time I've personally had a problem likely contributed to by a buffer was one of the Spikes T2 buffers in a mid length, using PMC Bronze and in cold temps. It simply was too sluggish to cycle. Swapped to a carbine buffer and no further issues, T2 ran fine in a barrel with a large gas port. No more proprietary stuff here for springs or buffers.

ETA: buy yourself some buffer weights and you can just order carbine buffers then tune from there.

Benefit in what way?

Over gassed barrels can cause wear faster, give the shooter more gas in the face, if you end up suppressing, extreme amounts of gas in the face, have more recoil and have a higher probability of malfunction and broken parts

Most of my suppressed carbines run an H2 and are reliable and soft shooting. They also shoot well unsuppressed.

I'm also running a BA Hanson 11.3" with an VLTOR A5 receiver extension and A5-2 buffer and JP spring suppressed and it is amazing. So amazing that I may switch all my guns to an A5 setup.

Really? With the "Spikes- Electro Polish 17-7 spring"?

I love forums as this really adds to things as mine feels too strong, as yours too weak.... Hmmm

The coils on mine look thicker than a lot of factory springs also, its probably the most beefy spring I have by far....

Most importantly, Do you remember what year or time frame that you bought it in?

I did in approx 2013-2015 I THINK but if yours is way prior, makes me wonder if they were too weak and if they overcompensated when upgrading....

OR

if yours is from a later period than mine, that means the exact opposite and means they were originally too strong.

I know springs can have inconsistencies Lot to Lot BUT when you mention thin coils, this one is Beefy so makes me think that one of ours is a revised version....

Were they both like that?

The way you described it is how I feel about the Aero spring!

They likely do the job but have never encountered factory recoil springs that compress so lightly when new. They even "creak" when new like an old mattress.

The "Spikes" actually gives heavy resistance wive never encountered before on the final half and especially 1/3rd.... If going slow, it'll almost stop as if fighting to fly forward like an XP spring!

Damn thing has like a 2 seconds vibration after it slams home HARD!  Loud as hell! Rattles the entire rifle.

Has me VERY confused as to if the Spikes is closer to proper spec or if the Aero is, but both feel as if stronger & lighter than standard (the standard being an M&P spring for me)

I MAY have gotten a spare one in the past year or so as an add-on to meet a "Free Shipping quota", I cant remember if I kept it in the cart but if I have it, I'll be comparing it tomorrow! After 5+ years, it'll either be the same, very similar, or VERY different and like yours.

Also, many companies Ive asked (well, Spikes and Aero) say "Our springs are factory spec" but that can mean their own proprietary spec unless their supposed to use milspec standards... IDK

Which companies use a milspec spring (or very common strength) that one can consider the "proper AR recoil spring strength"?

Id like to order one to know how a "standard" Springs SHOULD feel when new, to have a proper conparison as many parts kits springs vary so much ive noticed, and being I like to tune buffers, I dont like that as it can change things big time if indeed too light it too weak compared to most brands...

Try that upper on one of the carbine lowers and see how it shoots.

What about the A5 do you find amazing? I had five uppers last year with A5 and carbine lowers doing some magazine testing and out of 5 or 6 very experienced AR shooters pretty much everyone thought the H was the most controllable with the A5 and H2 being mostly indistinguishable.  Heavier A5 buffers A5-3 and -4 made the gun more difficult to control during recoil.  

We pinned down the feed issue to the A5 and got rid of it.

Yes, Spike’s P/N SLA501S

On mine the wire is just slightly thinner than normal, say .070” versus .071”. Not something you’d notice by eye.

Not really, but if I had to guess I’d say 2017–2019

Last one I bought was from BCM, but there are lots of places that sell them.  Look for mil-spec stainless.

As a sanity check, this morning I compared the strength of a bunch of springs, using a different approach than I had years back when I just had gotten the Spike’s.  Using a kitchen scale, I estimated the force required to compress the spring to where the face of the buffer is even with the lip of the buffer tube, as when the bolt is forward and locked.  Take these numbers with a grain of salt because my set-up isn’t very stable, but here’s what I got:

BCM: ~6.3 lb.  Various other basic carbine springs were similar, ranging from say 6.2 to 6.6.

Sprinco blue (extra power) ~7.8 lb

Sprinco(?) yellow (reduced power) ~5.7 lb

Spike’s ~5.8 lb

These results are reasonably consistent with what I had observed previously by a completely different technique.

ETA:  I re-read your post and noticed that you have a Damage Industries chrome-silicon spring. Mine measured about the same as the BCM, say 6.3 lb

I've always read the discussions on buffers/springs with mild interest.  I've never given a lot of thought to them for my rifles.  I'm running 1 rifle length gas with carbine stock/buffer/spring, 4 mid length gas (1 rifle length stock/tube, 3 carbine) one carbine gas with carbine stock and an 8.5" pistol.  

I couldn't tell you what weight buffer I have on any of them.   They all are very reliable and shoot fine, so I've taken an "if it ain't broke, don't fix it" perspective on that stuff. I use the money to buy more ammo.

Now that you mention it, the actual overall diameter of the Spikes spring indeed seems like a slimmer profile, and would make me think it snaking up in the tube more would make it seems as if stronger when compressed, although if yours is lighter, then im going to conpare to a newer one.

Maybe the older ones we're heavier than milspec and they changed it to where the newer are lighter on accident. Will see!

Also, the guy who makes the Tubbs spring did a video showing a bunch of springs at rest, and while compressed, and the differences were dramatically different.

I think "consistency" was the key but their were spme other factors involved.

He has a setup for weight and the side cut out of a buffer tube, but often doesnt mention brand except his own, but still very educational!

Who would have known springs were so different on the market!

In the day and age that we live in with most FSB's have gone to the wayside and a market flooded with adjustable gas blocks, why would you use anything other than a standard rifle or standard carbine buffer?

If you have a fixed gas system you are forced to play with buffer springs, BCG weights, and buffer weights.

Buy a superlative arms adjustable gas block and be done with it.

I’m using a BRT on a couple of rifles, they’re great. I always have them configured to use H or H2 buffers, that way I can drop a carbine buffer in if reliability becomes a concern.

I don’t know how big of a difference that might make, but it seems logical.