Anyone actually see these issues with 6mm ARC?

[LRRPF52]

Once I had developed my fundamentals, the idea that I could achieve more, faster, became attractive. If I am trying to win and be competitive, why not use whatever I can as an advantage within the parameters allowed?

Just about two years ago, after I had waited for my buddies to shake things out, I jumped into the world of 6mm ARC. It gave me large-frame ballistics in a small frame. It’s a beautiful thing, in theory. That’s just not how it worked out for me. The 6mm ARC has had more failure points than any other platform I’ve ever used for any reason.

Q: Can you get into some of the issues you were experiencing?

I have had an astronomical amount of carbon buildup that has completely seized my gas tubes in as little as 500 rounds and ONLY as many as 1,000 or so. That has happened consistently every 500 to 1,000 rounds for 8,000 rounds like clockwork for the last two years.

The second issue is the bolt. Generally, the 6mm ARC uses a 6.5 Grendel bolt and extractor, which is inherently frail. I’ve seen a number of, mine included, but other close competitors and friends of mine, snap extractors, crack and blow bolt lugs. Because of the case geometry, feeding of the system itself is not as ideal as other cases are. If I had to summarize, the level of maintenance I have had to put into this system to use it is exhausting. I have to track rounds on my gas tube, bolts, and extractors.

I’ve been seeking the answers to what’s been happening with my equipment and with my buddies’ equipment. There are easily 25,000 rounds between a handful of us on the clock, with 6mm ARC over the past two years. The only data point I can find is how we use our equipment versus others who are not competing with it. I see prolonged life and a lack of malfunctions for people who are hunters or recreational shooters, not “violently” using this platform.

6mm MAX Q&A

Specific problems he stated he and other competitors have experienced with 6mm ARC:

* “I have had an astronomical amount of carbon buildup that has completely seized my gas tubes in as little as 500 rounds and ONLY as many as 1,000 or so. That has happened consistently every 500 to 1,000 rounds for 8,000 rounds like clockwork for the last two years.”

* "Generally, the 6mm ARC uses a 6.5 Grendel bolt and extractor, which is inherently frail. I’ve seen a number of, mine included, but other close competitors and friends of mine, snap extractors, crack and blow bolt lugs.”

* "Because of the case geometry, feeding of the system itself is not as ideal as other cases are.”


The part about gas tubes caught my attention, because I’ve been shooting 6.5 Grendel about 10-20x more than the average shooter since 2009, mostly during multi-day higher volume shoot schedules. I have never seen a clogged gas tube. I’ve been shooting the 12” Grendel suppressed with an adjustable gas system inside the bolt carrier (Bootleg), so that one would see a clogged tube if any of them would, and I’ve been shooting it as my primary Grendel for the past 6 years just to see how it would perform.

I know Grendel has a lot more bore volume than 6mm, so that could be a contributing factory with slower-burning powders and too-short of gas systems.

Has anyone else that shoots 6mm AR or 6mm ARC seen clogged gas tubes?

I would also be interested to see what bolts he’s been using, and what magazines. 6mm has different ogive and neck geometry that is of course smaller, so it might have more of a tendency to hit the edge of the feeding cone inside the breech after passing through the barrel extension teeth.