Ive been using the A5 RE since it was released years ago. During that time I have Used every type of upper under the sun on it and it functioned amazingly well with all of them .
I was most surprised to achieve reliable function with the following four uppers:
20" BCM A4 Upper with 5.56mm and .223
10.3" Small gas port (.068) upper with 5.56mm ammo unsuppressed and LMT E Carrier
9" AAC 300BLK with subsonic Gemtech ammo unsuppressed
12.5" BCM Suppressed Using 5.56mm
It appears to me that not only do all common AR platform uppers function with this buffer, they do so reliably. Given that, are we safe to recommend the A5 RE in every situation where a collapsible stock is wanted?
I’m obviously biased because i have not yet encountered a setup that didn’t run with the A5 system…but I’m going to say that, yes, the categorical recommendation of the A5 system is not only acceptable…It’s preferred.
I also have an SR15E3 and an A5 stock, but with the stock A5 spring. Weak .223 is sluggish, but runs fine. The A5 also works flawlessly on my BCM 11.5", Colt 6920, and BCM 16" midlength. I can’t think of any issues I’ve had that the A5 was responsible for.
When you find out, let me know. Personally I haven’t come across anything yet. I install them on all of my own personal rifles, at least everything assembled in the last couple of years or so.
As far as function, no. I see no reason to not use the A5 type action system properly sprung and and weighted for the application over other action systems.
The few exemptions include, but not limited to are samples that require a balance in terms of items regarding OAL. For example, with an OAL concern, what is better? A 10.5" with an A5, or a 11.5" with a conventional H2, both properly gassed obviously? Another that comes to mind is 9mm blowback AR’s, but that’s a different topic to discuss.
Most configurations will run with just an H buffer.
However, the A5 will not only run, but it is extremely consistent with different loads.
Whereas with standard buffers you will see the ejection change and feel the cycle change with hotter and weaker loads, with the A5 it seems much less sensitive to this and seems to cycle about the same no matter what.
Let’s say I’m playing devils advocate, as I know the A5 has a wider array of function. The H2 carbine can induce less wobble and 100% reliability or an intended load that runs 100% for an intended use.
What would the A5 offer?
Does the margin of reliability counter the reduction in wobble that the carbine action system could offer? The argument has been made that the that the carbine H2 would be the choice for faster engagements over the A5 type of system. Not saying that proper “follow through” was done incorrect.
Ive been thinking about using the Vltor A5 system on a 14.5 inch carbine gassed setup (bcm upper). I see that most people are saying the A5 is good to go on most all properly configured uppers, but I feel compelled to ask, can anyone anticipate any issues with the aforementioned setup? Not at all new to the AR platform, but Im totally new to the A5 system. What is the difference between the RE-A5 and the RE-10/A5SR? one is six position and one is 7 position, but beyond that, is there any functional difference between the two? To further complicate things, I was perusing bcm’s website and I noticed they are selling the BCM intermediate receiver extension. It looks like its just a vltor A5, but it is an 8 position receiver extension. What is that? Is there a functional difference between the bcm/vltor intermediate RE (8 position) and the vltor 7 position A5? I did use the search function, but I didn’t see anything addressing this. Thanks for any help!
My BCM 20" rifle and 14.5" middy both run great with green Sprinco and standard A5H2 buffer. I’ve run my 14.5" middy upper on that lower enough to trust it. It cycles fine and locks back every time. The weakest ammo I use is brass .223. This morning was a mix of Fed XM855, Fed XM193 and Fed American Eagle .223. Flawless through both uppers. Honestly, the 20" upper felt more sluggish with the .223 than did the “ultra-picky-ammo-sensitive-finicky-unreliable” 14.5" middy. Anyway, my small sample of two.
ETA: My buddy’s BCM 14.5" carbine upper ran great on my A5 lower also.
That’s kinda what I’m getting at. IMO, the A5 does make a lot of sense and is a better mousetrap theoretically.
But in reality, I’ve seen a BUNCH of ARs from 10.3-20" all run fine on carbine springs and H-H3 buffers. When a gun doesn’t run, it’s almost NEVER fixed with a rifle spring and buffer. Unless you’re playing with some bottom-end junker.
I do run them like many of you. But I decided to try and not completely rebuild a wonderfully built LMT 10.5. Just changed h buffers to heavy. We all do overkill to build a better mousetrap. It’s part of the deal, but the A5 is good kit for sure.