The Vltor A5: My journey to...and away, from it.

[Unobtanium]

About a year ago, I began experimenting with the Vltor A5 system. My rifle is a 16.1" DDM4 midlength gas, and I used the A5H2 buffer and mil-spec action spring that came with it. Both suppressed, and unsuppressed, with a variety of ammunition, I felt that the function was very smooth. Follow-up shots were honestly faster, and recoil was perceived as less.

The first carbine course, however, that I took the rifle to, I began to get malfunctions once the magazines got dirty. Specifically, the BCG would fail to fully strip a round from the magazine on reloads, or the BCG would fail to fully seat having stripped a round. It was never an issue that presented during live fire, but only on reloads. Still, it irked me.

Today, I cleaned my rifle, and lubricated it lightly with Weapon Shield. The BCG is a Fathom Arms QPQ'ed BCG with a Colt ejector spring and a Ken Elmore "Green" extractor spring (of note, some failures at the course I attended involved the round not fully leaving the magazine, removing "over-spring ejector/extractor" from the equation as the culprit).

I brought two lowers with me. One is a factory DDM4 lower with a Sprinco Blue spring and H buffer, and one is the factory DDM4 lower using a Vltor A5 with H2 buffer and mil-spec spring. After I got home, I measured the spring. It is exactly 12.5" long, which is directly in the middle of the specification for a M16 action spring. It has roughly 2,000 rounds on it, and had less than 1,000 when I first began having issues.

During my testing, I had 3 failures with the Vltor A5 system to fully strip and seat the first round in the magazine. Two of these are seen in slow motion in the videos to follow. Using the Sprinco Blue spring, and H buffer, shot-to-shot was a bit more "bouncy", and there was more muzzle-dip upon dropping the bolt on a fresh magazine. Of note, all initial shots show the bolt-release being depressed (fully and swiftly), and the magazines are fully loaded G2 PMAG's. I will let the following videos speak for themselves, as I use IMI MK262, PMC Bronze .223, and Wolf 55gr Polyformance to demonstrate how each performs with each action system, both suppressed (Surefire 556-212) and unsuppressed (-212 FH).

Wolf Polyformance 55gr .223 w/ Vltor A5:


Wolf Polyformance 55gr .223 w/H buffer and Sprinco Blue:


PMC Bronze .223 55gr w/ Vltor A5:


PMC Bronze .223 55gr w/H buffer and Sprinco Blue:


IMI MK262 w/ Vltor A5:


IMI MK262 w/H buffer and Sprinco Blue:


Vltor A5 failure to chamber fully:

[Unobtanium]

I called Sprinco: "Everyone at Vltor runs our green spring in their A5's. It is about 3-5% stronger than mil-spec."
I called Vltor: "Don't run anything but a mil-spec rifle spring. It will cause problems. I will look further into this and call you back."
I measured my Vltor spring against a brand new Vltor spring I have laying around. They are literally identical in length.
I'm going to be a rebel and buy a Sprinco Green spring...

[ReverendMeat]

I have heard that using the sprinco green with the A5 tends to cause short stroking, interested to see how it works for you as the only AR I have left has an A5.

[rob_s]

I know this monkeying with buffers, springs, extractors, gas ports, etc. has become quite popular in the last few years. I never have really understood the fascination. Fixing what ain't broke, I guess? I hear guys show up to matches talking all about their secret recipe of fiddle-fart only to see them come in five spots below me with my iron-sighted, fixed-stock rifle. I couldn't tell you what spring, buffer, or gas port were used in the gun.

[Failure2Stop]

I couldn't tell you what spring, buffer, or gas port were used in the gun.

Obviously an Ultra-Spring Green/Red/candystripe with blue polkadots and a 9mm buffer with the last weight replaced with a white charm and a rifle length port at shoe size divided by pi applied to a 3/4 laffer curve.

[littlejerry]

I agree with this sentiment, although don't think it really applies to the A5. The A5 is a standard rifle spring with a short buffer that fits into a shorter buffer tube. It's cinematically identical to a rifle system, but more efficient with the space it uses.

[Unobtanium]

Technically, the A5 should be a better mousetrap. I just think it needs a bit more spring. Of course, I think everything needs more spring. I had the same issues with another rifle using a H buffer and Carbine spring like it came with until I switched it to a Sprinco. The mil-spec spring does not do well when the magazine feed lips are dirty/grimy from shooting suppressed. Causes cases to stick a bit, and prevents bolt-drop from working 100%.

[orionz06]

I agree with this sentiment, although don't think it really applies to the A5. The A5 is a standard rifle spring with a short buffer that fits into a shorter buffer tube. It's cinematically identical to a rifle system, but more efficient with the space it uses.

Technically, the A5 should be a better mousetrap. I just think it needs a bit more spring. Of course, I think everything needs more spring. I had the same issues with another rifle using a H buffer and Carbine spring like it came with until I switched it to a Sprinco. The mil-spec spring does not do well when the magazine feed lips are dirty/grimy from shooting suppressed. Causes cases to stick a bit, and prevents bolt-drop from working 100%.

Yup to both. That's what really pisses people off about the A5, it's not fiddlefuckery, it's just known good parts compacted down.

[littlejerry]

I agree with this sentiment, although don't think it really applies to the A5. The A5 is a standard rifle spring with a short buffer that fits into a shorter buffer tube. It's cinematically identical to a rifle system, but more efficient with the space it uses.

Autocorrect.... Kinenmatically, not "cinematically"

[BWT]

I had a moment today with my Sionics Complete Lower Receiver with the A5 System (there was a sale and it was $40 or so more expensive than the regular carbin extension a year or so ago; I thought I'd give it a try) that this thread came rushing to my mind.

I took my Midlength BCM Upper that I've never had a malfunction that is attributable to the gun (3 magazine issues and one 1 stuck case); I've owned it since about 2009. It probably has in the ball park of 8,000-10,000 rounds through the gun.

I ended up testing the Sionics lower with the BCM Upper pretty much without issue except I had one failure to extract. There's a lot of variables involved, I forgot lubricant and both the SBR and Mid Length had not been cleaned since shooting steel cased at my last match/outing; they were also pretty dry from not being used for probably 6-8 months. I was also shooting various ammo; specifically 20 of independence 55 gr 5.56mm (I've since heard reports of inconsistency with velocity; it was very smokey compared to the other XM193 analogs not sure if that means a thing), I shot some PMC 5.56mm XM193 (40 rounds), and about 110 rounds of Federal XM193. About half through the SBR and half through the Midlength with this single magazine.

I ejected the magazine, cleared the casings in question, and I should've taken a picture but I didn't. Got the loose live round from the floor of the range put it back in the magazine, and finished the rest of the magazine in the SBR (I figured if this thing is going to fail spectacularly it's going to be in the 12.5'' because of the shorter dwell time and shorter receiver extension); it finished the dozen or so rounds in the magazine and locked back without issue. I shot another 80 Federal XM193 through the magazine through the SBR and Mid-length without issue.

So, I'm at the point I think it's one of three variables. A.) The A5 system (ejection wasn't erratic but was between 3-4), B.) The lack of lubrication and polymer coating residue in the chamber from my last match (about 120 rounds of Wolf), or C.) the Independence ammo (I didn't find two live rounds on the floor only one; so it may've just short-stroked and not kicked the round out) I priced out a replacement RE and if I see this again I'm contemplating replacing all of it with the system I've had a pretty awesome experience with Mil-Spec Carbine Spring with H or H2 buffer (http://www.bravocompanyusa.com/Stock-Hardware-Mounting-Kit-Mil-Spec-p/bcm-stock-hardware-kit.htm ).

I normally buy factory complete uppers, lowers, or rifles; I'm now leery of the A5. I didn't notice a different in my experience over the carbine spring. What I'd really like to see is how it performs with Steel cased ammo; that range only allowed brass case ammo and it was all XM193.

My heart is uneasy; I'm really tempted to just swap it out but I think I'll wait and get a good number of steel cased .223 REM through it and see if it fails.

Thanks and God Bless,

Brandon