A5 Questions

[Iraqgunz]

Since no one bothers to use the search feature that has A LOT of information about the A5 going back several years and across multiple configurations the real benefits are the ability to use multiple uppers with one configured lower. That also means suppressed, etc...

Generally speaking, an A5 lower with a USGI or Sprinco green spring and A5H2 will work with a wide variety of uppers and ammunition types.

[0uTkAsT]

Let me give it a shot:

- in my opinion A5 would probably work better (i.e. in a wider range of uppers and ammo variance) vs Geissele Super 42. Will you see a difference - probably not as much as you expect to be honest.

Thanks, this is exactly the kind of feedback I was looking for.

1. Personally, I wouldn't switch to an A5 in your case since you say your 11.5" already runs like a top. If you're happy with it, don't mess with it. I put an A5 in all of my NEW builds. I don't bother switching old systems over if they run well. If money is no object though, then by all means, plug and play. You can always switch back.

2. Ive never messed with mixing weights, so I cant comment on that.

3. Not knowing the exact gas port sizes on my rifles, (and having one of every A5 buffer weights), I start with the A5H4 and do one round lock back tests. If it fails to lock to the rear on an empty mag, I drop to the A5H3, test that the same way, and repeat until the rifle locks back every time.

4. You will be the ultimate Instagoogletweetface!

Solid advice. The gun in question runs great, but it's a suppressed carbine-length DI with a slightly oversized port so needless to say, there's room for improvement. I keep being told over and over that an A5 would smooth out the system as a whole, but if it will only do that to a degree that's barely appreciable, I'm probably going to do as you suggest and just try it on a new gun down the road.

my .02 cents

-yes "i" believe it's an upgrade , even to a gun that's running fine. it should smooth out the recoil impulse some and help the gun run better with different ammo/conditions

-you can switch around weights but i believe the h4 is different as in there is a spring in the weight stack to always keep them biased

-just get an h4 and maybe an h3 to test with , with a suppressed only gun you won't need any of the lighter weight buffers. slash makes heavier buffers for the a5 system but they don't use the spring loaded weight stack i don't beleive

-i think your more likely to gain instagram followers with the geissele gear


i run a super 42 setup in a 12" lmt piston upper and it's nice. i believe it's benefits are no spring noise and longevity. it does seem a little stiffer than a regular carbine spring.

i run an a5 setup on a kac cqb upper , i think i'm using an h4 in it but i'd have to look. the cqb barrel's are supposed to have a .70 gas port. if i swap upper's around by my "seat of the pants feel" i think the a5 has a smoother recoil impulse that the super 42 but YMMV as recoil is subjective.

i have a centurion 11.5" barrel with a .065 gas port and the recoil impulse is much more noticeable with that setup than either the lmt or kac. if i move that upper between the super 42 and the a5 setup the difference is very noticeable to me , super smooth.

if your barrel has a gas port of .073 and you run it suppressed all the time i think you would get more juice from the squeeze by choking down the gas port with a brt gas port instead of buffer setup's.

Well noted, thank you for your input and sharing the info about the spring loaded weight stack... I'd never heard of that before.

I'm in perfect agreeance with you on the Super 42 as well.

Sounds like my best place to start would be with an A5H4 and work down if I do go this route, but I'm not going to mess with the gas on this BCM. I do eventually want to build a Sionics rifle with a properly sized port from the get-go, however. Maybe I just need to keep feeding this gun and stop worrying about fine-tuning it, and look into putting a Sionics together sooner rather than later and work on getting that one dialed in perfectly. Sounds like that is a better foundation for the sweet-shooting dream carbine I've always wanted anyways.

Do you have more than one rifle? It sounds like it. Installing an A5 buffer system won’t tear a hole in the space-time continuum. You will just learn what the difference is between your carbine setup and the A5. I use them on my new builds and I pulled some carbine buffer systems off existing “running like a top” AR’s and guess what?

They all kept running. Like the proverbial top. I for one believe there is a difference. Since I ran both on the same rifles. I’d like to think I own up to my own bad ideas and don’t feel the need to justify a purchase. Certainly if it brought zero value to the table I doubt I would had purchased 20+ A5 type systems to date. (Mine and builds I’ve done for others all use an A5.)

If you decide to give it a shot, I believe I used an A5H3 and green Sprinco on my 11.5, that was a Daniel Defense barrel. (I’m also pretty sure I ran that same in my Centurion Arms 12.5, I’ll have to check my config book.) My 11.5 ran extremely well. Perfect I would say. I’ve also got an A5 on a 8.3(300BLK) 10.3, 12.5, two 14.5’s and a 16” (no longer have) as well as my Mega/LMT MWS 16” AR-10. (UBR Gen 2) I ran it on and 18” 308 as well. Of course I did not use an A5 buffer on the 308’s, but a KAK heavy on the precision rig m and a H2 carbine buffer on my LMT.

If this was you’re only rifle....well I might tell you to go for it anyway, but definitely if you own more than one AR, it’s a low risk move. If you don’t like it, I’m sure you can sell it. I’ve bought several on the E&E. I don’t believe in magic or a talisman. I believe in quality, purpose driven builds and in my opinion the A5/intermediate buffer system has a specific role in that mentality. It’s all I use, barring specific tubes on my PDW stocks. There are quite a few threads on the A5 here at M4C and some opines differ than mine, but I believe they are all worth a search and a read through.

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There is a crapload of good info here, thank you Robert. I'm trying to digest all of that right now.

Since no one bothers to use the search feature that has A LOT of information about the A5 going back several years and across multiple configurations the real benefits are the ability to use multiple uppers with one configured lower. That also means suppressed, etc...

Generally speaking, an A5 lower with a USGI or Sprinco green spring and A5H2 will work with a wide variety of uppers and ammunition types.

I don't want to be seen as "that guy" who didn't try to find the info before asking, but I also didn't want to be "that guy" necroposting in a long-dead thread to ask something specific I wasn't able to find either.

Since I see you work at Sionics, might I ask if you guys would ever sell stripped lowers or ones with an A5 tube vs. the carbine tube? And do you have a storefront in Tucson or is everything done online?

[17K]

Buffers are for reducing carrier bounce to reduce the chance of a light strike during high rates of fire. If your rifle is showing symptoms of being over gassed then reduce the gas flow and delay bolt unlock. We call it over gassed not under buffered for a reason.

This guy gets it.

In semi-auto lowers the buffer almost doesn't matter. It's an easy thing to tinker with and the aftermarket responds with plenty of 'options / upgrades' that people buy and then proclaim that they've found the perfect recipe to improve the function of an already functioning gun.

[SteveL]

Since I see you work at Sionics, might I ask if you guys would ever sell stripped lowers or ones with an A5 tube vs. the carbine tube? And do you have a storefront in Tucson or is everything done online?

Obviously I'm not IG, but I can tell you that at one time Sionics did offer their lowers with the A5 system installed at the factory as an optional upgrade. I know because I bought one. However, they eliminated that option quite a while ago. When I inquired about it they told me it was because it was too difficult/troublesome keeping the A5 components in stock, which is a shame IMO. Perhaps IG can offer additional insight.

I've always thought it was odd that when the A5 system was originally developed by Vltor, the kit included the A5H2 buffer by default. The founder of Vltor is now employed by BCM. As I recall BCM lowers or complete rifles are available with the A5 system installed, but they include the A5H0 buffer as the default. I'd like to know why they use the lighter buffer. I have two 11.5" BCM uppers on lowers with A5 systems. One has an A5H2 and the other has an A5H3 and they both run fine with any ammo, suppressed or unsuppressed, so I don't see where the lighter buffer would be beneficial.

[Wake27]

Obviously I'm not IG, but I can tell you that at one time Sionics did offer their lowers with the A5 system installed at the factory as an optional upgrade. I know because I bought one. However, they eliminated that option a quite while ago. When I inquired about it they told me it was because it was too difficult/troublesome keeping the A5 components in stock, which is a shame IMO. Perhaps IG can offer additional insight.

I've always thought it was odd that when the A5 system was originally developed by Vltor, the kit included the A5H2 buffer by default. The founder of Vltor is now employed by BCM. As I recall BCM lowers or complete rifles are available with the A5 system installed, but they include the A5H0 buffer as the default. I'd like to know why they use the lighter buffer. I have two 11.5" BCM uppers on lowers with A5 systems. One has an A5H2 and the other has an A5H3 and they both run fine with any ammo, suppressed or unsuppressed, so I don't see where the lighter buffer would be beneficial.

That’s come up before, I think a BCM rep said it was the ideal weight or some other weird answer. I have a pinned 14.5 from them that has used a springco green an -3 for years.


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[Iraqgunz]

We do not use the A5 tubes any longer as the supply was never consistent and it caused us to have to wait extended periods before we were able to deliver. There were also issues with buffer supply as well.

Thanks, this is exactly the kind of feedback I was looking for.


Solid advice. The gun in question runs great, but it's a suppressed carbine-length DI with a slightly oversized port so needless to say, there's room for improvement. I keep being told over and over that an A5 would smooth out the system as a whole, but if it will only do that to a degree that's barely appreciable, I'm probably going to do as you suggest and just try it on a new gun down the road.
Well noted, thank you for your input and sharing the info about the spring loaded weight stack... I'd never heard of that before.

I'm in perfect agreeance with you on the Super 42 as well.

Sounds like my best place to start would be with an A5H4 and work down if I do go this route, but I'm not going to mess with the gas on this BCM. I do eventually want to build a Sionics rifle with a properly sized port from the get-go, however. Maybe I just need to keep feeding this gun and stop worrying about fine-tuning it, and look into putting a Sionics together sooner rather than later and work on getting that one dialed in perfectly. Sounds like that is a better foundation for the sweet-shooting dream carbine I've always wanted anyways.


There is a crapload of good info here, thank you Robert. I'm trying to digest all of that right now.


I don't want to be seen as "that guy" who didn't try to find the info before asking, but I also didn't want to be "that guy" necroposting in a long-dead thread to ask something specific I wasn't able to find either.

Since I see you work at Sionics, might I ask if you guys would ever sell stripped lowers or ones with an A5 tube vs. the carbine tube? And do you have a storefront in Tucson or is everything done online?

[prepare]

What’s up with the supply issue? When your product is in demand why not just make
more?

[17K]

What’s up with the supply issue? When your product is in demand why not just make
more?

It's been out for over a decade and hasn't gotten that much traction. Outside of this forum they're not that popular.

[Short_barrel_daddy]

It's been out for over a decade and hasn't gotten that much traction. Outside of this forum they're not that popular.

I’d say that is changing, or at least starting to, with companies like solgw using them on complete builds and vltor stating they are increasing production this year.

[0uTkAsT]

With BCM making their own A5 receiver extension and the original Vltor guy now working for them, I'm surprised that there aren't any factory BCM rifles or lower assemblies sporting them (besides the Mk12). I know G&R sells a complete lower with the A5 extension, but it seems to be an exclusive sort of deal because I haven't seen them anywhere else outside of that. Who knows, but the supply issues are odd considering the overall lack of prevalence in the current market.