A5 Buffer System on Grendel

[Londerko]

[10esmus]

I run A5 tubes with A5-0 buffers on my 20" and 12" Grendels* and all my .223s. They work.

* The 20" Grendel has an adjustable gas block, and the 12" Grendel uses a Bootleg adjustable gas carrier, to that isn't exactly apples and/or oranges.

The A5 tube with a SBA3 stock comes out to 13" LOP, so it comes in under the ATF max LOP for pistols (13.2? 13.5?)

[rebby]

I run the A5 on 3 of my guns. I have the standard weight buffer (H2) in my 18” LaRue upper (non-adjustable GB). I run an H3 in a 20” and a 16” (both non-adjustable GB as well).

Personally, I love the A5 system and it’s all I run with the gen2 UBRs. I run my gen1 UBRs out one notch anyway so I actually prefer the little bit of extra length.

[Londerko]

[98Z]

Thanks for the responses guys.
I actually am using a UBR 2 on my grendel and am currently using the included spacer and a carbine buffer and spring that I already had. But since the stock is setup to use the A5 system I was thinking about giving it a try
Is the “standard weight” the H0 or H1?
My barrel is an 18” RLGS with a non adjustable gas block. With the carbine buffer and spring the brass ejects and hits the deflector then throws it to about 4 o’clock.... just trying to decide what weight buffer would be best for my setup.
Also, are you guys using standard cheap A2 style Rifle Buffer Springs? Or anyone using the JP polished or the Tubbs (it’s supposed to work on carbine and rifle lengths).
Rebby: what length gas system does your 18” Larue barrel have?
Thanks for the help guys
Sorry for all the questions

I'm a firm believer in the A5 system on a Grendel. I'm currently at 4 Grendels, and 3 are running the A5 system.

18" RLGS is the VLTOR A5 H1
16" CLGS is the VLTOR A5 H1
18" MLGS is the only one that doesn't have the A5 system, just an AR15 recoil system, and it's running an H buffer. It should have a VLTOR H1 or H2 in it, and I'll change that entire recoil system up in the future.
12.5" CLGS is the VLTOR A5 H0, but that gun has the LAW Tactical folding stock adapter, with a heavy addition to the BCG body.

They all run flawlessly - but I'll get that 18" MLGS gun into an A5 setup.

Right now, I'm working on Grendel #5, a Mk12 Mod H build with 16" MLGS, and it's already got the A5 H2 in it.

Grendel #6 is possibly in the works, with a 10.5" barrel. I'm ironing that out...

Before too long, Sprinco will announce their "adjustable buffer kit," and they made an A5-lengthed buffer body. It's an adjustable setup that allows you to tailor the buffer weight to what you want or need. If you're going to make alot of little Grendels, one of these would be perfect, no matter what gun setup/config you end up with. Tailor that barrel and gas system to what works perfect for you - then get that closest A5 buffer. Save the kit for the next one...

EDIT - Spring answer. I've never used the VLTOR A5 spring. I've used two Armalite AR15 Rifle springs, and 1 DSG Arms AR15 rifle spring. The current Mod H build-in-progress has the DSG AR15 rifle spring. The previous 3 run flawlessly with those springs (Armalite or DSG AR15 rifle springs).

[rebby]

Thanks for the responses guys.
I actually am using a UBR 2 on my grendel and am currently using the included spacer and a carbine buffer and spring that I already had. But since the stock is setup to use the A5 system I was thinking about giving it a try
Is the “standard weight” the H0 or H1?
My barrel is an 18” RLGS with a non adjustable gas block. With the carbine buffer and spring the brass ejects and hits the deflector then throws it to about 4 o’clock.... just trying to decide what weight buffer would be best for my setup.
Also, are you guys using standard cheap A2 style Rifle Buffer Springs? Or anyone using the JP polished or the Tubbs (it’s supposed to work on carbine and rifle lengths).
Rebby: what length gas system does your 18” Larue barrel have?
Thanks for the help guys
Sorry for all the questions

Per Vltor the “standard” weight buffer system is the A5H2 (5.3oz). I actually had to edit my post above, my heavier buffer is the H3 (6.08oz). I’m using the Vltor “kit” spring w/the A5H3 and a quality chrome silicone rifle length spring w/the A5H2.

The LaRue Grendel barrels are mid-length gas.

The A5 buffers are just as configurable as a basic carbine buffer. Actually a little more so, if you crack one open you’ll find 4 weights in an A5 to the 3 in a carbine buffer. The catch on an A5 buffer is that one of the weights is recessed for a small spring to keep the weights forward when firing. This still gives you 3 weights to swap around though. Depending on what your existing carbine buffer is, I’d order whatever A5 will give you the correct configuration of weights so that you could go lightest (3 steel) to heaviest (3 tungsten). I think the A5H4 actually replaces the recessed steel weight with a tungsten one as well. For a spring, go with good quality rifle length spring and you should be just fine. I don’t obsess too much about springs anymore and have had good luck with quite a few, the only issues that I’ve experienced is when I come across a “basement bargain” spring.

Good luck!

[Londerko]

[98Z]

You guys are awesome.
Thank you so much for the responses.
I appreciate you taking the time to help me out.

98Z:
On your 18” RLGS did you try any heavier of a buffer than an H1? Or, what made you decide on the H1 vs H2 etc?

A5 parts were scarce when I built that gun, and the heaviest A5 buffer I could find in stock at the time was the A5 H1. That gun is the Ballistic Advantage 18" SPR-profiled barrel, almost a heavy barrel, and I'm running the VG6 300BLK 2-port brake on it, with the VG6 CAGE device - so that cuts a little felt-recoil from it. I do have that A5 H2 buffer now, for the next build, so I'll try it out in this 18" gun and get feedback in here. I'm supposed to shoot on Sunday, but the weather says "nothing but rain" all day. I'll keep this updated. I'm positive that the A5 H2 will be even better in that gun - depends on your ammo, as well. You'll have to shoot something "Hornady Black 123 ELD-M" or more in it, for a comparable result.

[Lastrites]

You guys are awesome.
Thank you so much for the responses.
I appreciate you taking the time to help me out.


Rebby:
I am currently using a standard carbine buffer. Just to be clear, are you saying that i could take weights out of the carbine buffer and swap them out with the weights in the A5 buffer? For example, turning an A5-H2 into and A5-H1 by removing a tungsten weight from the A5 and replacing it with a steel weight from the carbine buffer?

Yes, the weights in the buffer can be swapped around to change the total weight of the buffer, KAK sells a kit and individual weights if needed.

[Londerko]

[rebby]

98z
That is the exact same barrel I am using.
I would be very curious to see if it prefers the H1 or H2 buffer. I would imagine that either one is an upgrade from the standard carbine buffer setup I’m running in my UBR2.

Lastrites:
Thanks for clarifying that for me.
I’ve never opened up a buffer. Seems simply enough if your able build your own AR.
Good to see KAK sells the individual weights. Easy to get it just right without breaking the bank

Yep, what he said. The buffer opens up pretty easy, just drift the pin out and it comes right apart. If you do take the buffer apart just make sure to orient all the parts in the same manner when you put them back in. In the A5, the weight with the spring is in the back and, if I remember correctly, the spring it oriented toward the back (the buffer pad is in the back, I’m referring to “back” as toward your shoulder when you’re shoooting). It’s a lot easier than it sounds, basically take it apart swap out steel for tungsten or vice versa and put it back together in the same way that it came apart.

[Londerko]

Thank you
Did you guys that switched from a carbine buffer setup to an A5 notice a pretty significant difference?
Softer recoil? More reliable cycling?

[rebby]

Thank you
Did you guys that switched from a carbine buffer setup to an A5 notice a pretty significant difference?
Softer recoil? More reliable cycling?

To be totally honest, not really. I run an A5 on my UBR2's but don't feel like I'm at a disadvantage on my Carbine and/or rifle system equipped guns. That said, I do like the A5 system better, I haven't put a ton of rounds through them to see if it lives up to the claims of less wear and/or more reliability over time though.

When I'm building lowers that support the A5 system, I run with it but I don't lose any sleep about installing a traditional carbine system either. I have built a few guns for customers where they've opted against the A5 system even though their buffer system would support them though (more interchangeability). I've also had a few that have insisted on installing an A5 system. Tune them right and either one will run just fine, just remember that it's just one piece of a bigger overall system.

[Bowfisher]

Good info and to add to the questions, I'm thinking about trying an CTS hydraulic buffer on a Tubbs flat wire spring. Anyone ever gone that route?

[Londerko]

I do have that A5 H2 buffer now, for the next build, so I'll try it out in this 18" gun and get feedback in here. I'm supposed to shoot on Sunday, but the weather says "nothing but rain" all day. I'll keep this updated. I'm positive that the A5 H2 will be even better in that gun.