View Full Version : A5 buffer ??
If I want to an Ar buffer tube, from all the reading I have done it seems everyone seems to settle on A5H4 and green sprinco spring. or A5H3.
If I want the lower to be as friendly as possible to most uppers AND any suppressed uppers would have an adjustable gas block, which buffer would serve be best?
A5H3 or A5H4?
14" carbine
16" mid
9" 300BLK suppressed
11.5" suppressed or not
Is there one A5 buffer that would suit any / all of those?
I'm still not real clear on exactly what the buffer is solving or preventing.
The standard A5H2 is a great option.
Just because a given upper will run an H3/4, does not mean that is automatically the optimal choice.
Overly heavy buffers can increase nose diving on return to battery.
The standard A5H2 is a great option.
Just because a given upper will run an H3/4, does not mean that is automatically the optimal choice.
Overly heavy buffers can increase nose diving on return to battery.
Well that over complicates things. I thought you just wanted to find the heaviest buffer that will still cycle the gun.
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It would be overly simplistic to as a rule that a certain mass buffer would be the prefered choice for whatever "x" options are on the table.
An A5 can have a wider span of operation, that doesn't mean a certain mass will work with all of the options all the time. If the base system can barely run a 3 ounce buffer, how can that relate in proper buffer mass to one that could be 4 ounces heavier?
If you are going in blind, the A5H2 could be a preference without a can. More mass can be added with a can, or less mass could used in other circumstances.
An adjustable gas block can only reduce gas in its own increments. If it's on a under gassed barrel, it will never reach the potential it could have been without opening the port up.
It would be overly simplistic to as a rule that a certain mass buffer would be the prefered choice for whatever "x" options are on the table.
An A5 can have a wider span of operation, that doesn't mean a certain mass will work with all of the options all the time. If the base system can barely run a 3 ounce buffer, how can that relate in proper buffer mass to one that could be 4 ounces heavier?
If you are going in blind, the A5H2 could be a preference without a can. More mass can be added with a can, or less mass could used in other circumstances.
An adjustable gas block can only reduce gas in its own increments. If it's on a under gassed barrel, it will never reach the potential it could have been without opening the port up.
You touched on a good point about gassing. It's hard to pick just one buffer and spring for ALL guns when there are such wide variances in gas port size, bore size, gas length, and suppressor use on the OP's 4 guns, especially if some have short dwell time.
So do most people that use the A5 simply gather a few different buffers for different purposes. Like I said, I honestly don't understand what the more or lass mass is actually solving/improving/etc... I don't understand it's purpose. For instance I would never have thought about the larger mass returning to rest and causing a nose dive... now that's I've heard it, it makes sense.
But then you read... just went with an A5 and it cured everything including baldness.
So should I read that as... the length and design of the A5 is a nice setup, but you still have to tailor your buffer weight to the rest of the system?
I'm kinda lost in the "don't over think it" and trying to understand why it's not a cure all if used improperly.
I get the point about the system that could barely cycle a 3 oz buffer obviously can't have a heavier buffer. That makes sense. No, I'm not looking for heaviest that works for all..
I suppose what I was asking was there a 'sweet spot' that should work for everything and perhaps some go up or down looking for perfection.
But it sounds like what you all are saying is simply expect to buy and use an assortment of buffers as needed.
So if I were to start off with 2 buffers would the A5H2 and A5H4 be good choices. I guess I'm trying to figure out where my money would be best spent to start with. A5H2 and A5H3? Maybe that would be most practical?
I can't tell you what A5 weight works as I've not used that system yet, but based on your uppers collection I think what would be ideal is one lower for the 14" and 16" since their dwell times are the same, and a second lower setup for the short barreled suppressed uppers. That seems easier than trying to keep track of which upper likes which buffer and constantly swapping buffers out.
From what I have gathered from the threads and feedback from users on here it appears as though there are a lot of variables to consider. For example, if my rifle is set up with a 16" mid gas system, compensator or brake of some kind, I may not want all the reciprocating mass of the A5H4.
When the heavy buffer returns forward with the additional mass, it may cause an already soft shooting carbine to nose dive a little between shots. Its like an over-sprung 1911. The nose diving may be reduced by using a standard power action spring in this situation I would imagine.
I am still trying to wrap my mind around the spring and buffer combination and effects it will have on different systems. I currently am putting together a carbine with a Colt 14.5" barrel, LMT E-BCG, and Surefire Warcomp. I know the Warcomp does nothing for recoil, minimal as it may be with 5.56.
For this type of a set up I would assume the A5H3 or H4 with a strong spring such as the green springco spring may be the best choice. Then again, this brings up the concern of nose diving being exaggerated by the heavier mass buffer, heavy spring, and a directional push from the Warcomp.
The only way to find out what works best is to try it I guess. I will be buying an A5H3 and A5H4 buffer here shortly to try out and keep for different carbines in the future.
I would start out with a regular A5 and see how it runs.
I've never had an issue using a standard H2 buffer with stock spring on a stock full-auto 10.3" Colt (suppressed and un) to a 14.5" Colt and BCM carbine, 14.5" and 16" BCM mid, to an 18" and 20" BCM rifle.
The whole point of the A5 in the original HUGE thread, is that it will run on a wide range of uppers without having to swap springs and buffers. Then everyone talks about all the different buffers and spring combos they use.
The gas ports on those barrels is going to be the factor that dictates what buffer will run right. If they're all Colt and BCM barrels, then they'll all do fine with a standard A5 or carbine H2. If you have a gasser it'll likely run with everything you can put behind it.
Like others here, my bcm 11.5 chf runs on a A5H4 with green springco spring and lmt enhanced carrier
Without going over too many basics, let us say we do a compare and contrast. An H2 carbine action in a properly gassed system would have a certain operating range or span of use. An A5H2 in a properly gassed system would have a certain operating range or span of use. How do those compare? Would, or could a wider range of operation be judged as a possible negative in shoot ability? Some systems may shoot smoother, some may not depending on what is actually going on. When you study the system in operation, some things can become clearer. Timing of events can be crucial to understand how the two systems contrast.
Different things can do different things but in what ways they are different depends on the differences of the specific differences and how they effectively differ from each other.
If you take a narrow selection of the carbine H2 operation that only includes the system barely bottoming out the action spring, then, that system may be considered more shootable than another in use. That does not mean that it would be better or best overall, that would be a possible selection of that system.
An A5, in reference may have a wider degree in gassing range to operate, that doesn't mean that it automatically has the most preferred felt recoil in function. It depends on how you could compare the two. It may, or may not feel as good in function. The system still can have the ability to operate within its own range, comparing recoil between the two depends on their own reference point. So yes, different things can do different things, it just depends.
If you took a sample of operation of an H2 carbine and superimposed that to a possible A5H2, how could those compare and contrast? You could note that the centerlines do not align, that would seem to result from differences in time that either operate in.
What possible span of operation would be preferable to most? The wider span, or the shorter one? Sure, different things can be different. That does not mean a wider span of operation isn't available, or a negative determined by "feel". That would or could be short sighted, just depends on how on how things can turn out.
So change one variable and all variables change. I think I get the basic situation now. No way I could ever perfectly fine tune things nor one size fits all. It would always be subjective for me. If I can just get in a safe subjective range I will be ok. I'm thinking h2+h4 would serve any need I might ever have.
This shit is getting too sciencey for me. I'm just gonna keep mine at the heaviest it will run between H1-H3. If I notice a lot of reciprocating mass, maybe I'll drop the weight, but so far my wife's BCM has worked well between the H2 and H3 and about 1,500 rounds. My new Noveske is definitely getting one too, that thing has more recoil even though its got a dedicated brake vs the BCM comp.
So change one variable and all variables change. I think I get the basic situation now. No way I could ever perfectly fine tune things nor one size fits all. It would always be subjective for me. If I can just get in a safe subjective range I will be ok. I'm thinking h2+h4 would serve any need I might ever have.
Tom is tripping me out. A5h2 is 5.3 oz I think, making it heavier than a regular h3 but will run a 14.5 mid length and tula where the h3 proves to be too heavy. Riddle me that Tom!
Anyways, wider operation span with a5, don't throw it out the window with an a5h4. An a5h2 will run all your uppers while minimizing the abuse on parts with a regular h2. I would start with a5h2 or a5h3.
I think vltor named the buffers based on what carbine buffers they'd replace. If your uppers ran best w an h3, than use a5h3. If it ran best w a sprinco blue and h2, run adh2 w a sprimco green.
A5H0=3.8
A5H1=4.56
A5H2=5.33
A5H3=6.08
A5H4=6.83
H=3.8
H2=4.6
H3=5.4
HSS?=6.5
I stand to be corrected on those...
Seems like A5 is 'longer spring and one step up'
Not sure what that means other than I would expect slower overall response for equal values.
Tom is tripping me out. A5h2 is 5.3 oz I think, making it heavier than a regular h3 but will run a 14.5 mid length and tula where the h3 proves to be too heavy. Riddle me that Tom!
Anyways, wider operation span with a5, don't throw it out the window with an a5h4. An a5h2 will run all your uppers while minimizing the abuse on parts with a regular h2. I would start with a5h2 or a5h3.
I think vltor named the buffers based on what carbine buffers they'd replace. If your uppers ran best w an h3, than use a5h3. If it ran best w a sprinco blue and h2, run adh2 w a sprimco green.
An A5 will run with a heavier buffer than a carbine system because the spring on an A5 is a lot lighter.
I think the A5 is a great system, and a better mousetrap overall that the carbine system. But in all reality, with a properly gassed barrel, it doesn't do anything significantly different than a carbine system.
I'd get rid of an over-gassed barrel long before I swapped the receiver extension, spring, and buffer to optimize functionion with a sub-optimal barrel. Even if it was an over-gassed Noveske or Daniel Defense.
I wouldn't say that a rifle spring is a lot lighter, compare the Colt rifle and carbine springs in a simplistic fashion of L1 vs L2. If that basic comparison is made, sure more mass is possible, but there's more going on. The timing between the two can become more of a thing to look at. If you don't use up extra work to overcome tensions and stresses, that extra mass can go towards function. More mass options happen.
It is true that a barrel that is closer to the proper amount of gas to drive through better porting and gas system lengths could be the in system to be more important in span of use than a more timed base action system. That alternate could also be argued, depending on where they are in operation for either.
Knowing that both can have specific advantages that are not mutually exclusive overall, can mean the potential of a wide span or spans of operation may be had in conjunction within a balance.
I know this whole thing sounds vague, but there's no way for me post all the preface for this now. I'm running on limited sleep, so call me out if you want, I'll try to respond later on things.
For what it is, good, bad, or indifferent. The system as we know it now, cannot be the ultimate pinnacle of what it can be. Nor can it be the pinnacle of what may be without alterations to the base system that could make that happen.
I still have limited sleep, so work with me here on this.
Let us say we have a Colt 6921 as a baseline for this example. Using a carbine H2 with 5.56 pressure ammo can have a wide span of function.
When an A5 or rifle like action system is added, the increased buffer mass can increase in that same span of function. The question maybe is why? Sure some is mechanically attributed to the spring alone, from a simple spring an mass balance, but that doesn't cover the rest of the mass. Where does that come from or why?
Let us look at some basic things. Both travel the same distance in operation, but they do so in different amounts of time. The carbine completes the cycle of the action in a shorter duration of time than the rifle like action.
Initially, when the carrier receives enough work to begin movement in its free cam length passage it does so. The action system is dumb, it just does the work that it is given work to do so. The rifle like action system can take more time to complete the distance in the free length of cam passage. That difference in time makes the required work to initiate the rotational different between the 2 systems in the rapidly depressurizing barrel. Less work is less stresses, that is a AR carbine issue.
During the bolt caming on unlocking, the relationship is about the same as above. The carbine does it with more stress and work than the rifle like action. Again, less work is needed to unlock, that results in a higher mass in the spring vs mass variable.
During exhausting, through the ports before the key disengages tube, more gas can be released from a system that completes that event during a longer duration. Exhausting fouling out of the gun instead of into it is a general plus.
The increased time duration can reduce the hammer effects on the FCG and the lower, not saying that is major, but it does happen. Think about that registered lower users.
The rifle like action system spends more time in BCG over travel of the bolt stop than a carbine type. Many presume that magazine function in time is instant, it is not. Many things can help magazine function, reducing the available time isn't one of those.
This post isn't intended to be totally comprehensive at all. There is a lot going on.
Feel free to call me out, running 16 hours on 4 off is draining, so I'm sure I made some errors in just typing. Spell check is not friendly to me either.
Auto-X Fil
12-01-15, 18:43
In my experience, the longer travel of the A5 system makes it less affected by buffer weight. I can run H0 to H4 in my gun with no problems. I don't think the standard carbine setup would do that, but maybe they would on this gun.
The biggest differences for me are in recoil control. The A5 is so much softer-feeing.
They both travel the same distance. The difference is in time of the duration.
Auto-X Fil
12-01-15, 18:59
Oh, it hadn't occurred to me that the length increase of the A5 buffer and tube are the same, and cancel out. But of course that's what happens. Thanks.
There is only limited space in the system to do work.
Within these confines, some things can work together better than others potentially.
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