He’s definitely right about the magazines. I’ve been a Grendel shooter for a long time and the mags are the week point of the system.

I'm not saying he's wrong about anything he said. I did check and Geissele charges $125 for a 30rd 6ARC mag.

But it's clear that 338ARC has struck a nerve with him. Take into context that the "YQ" videos are marketing videos, I'd say he has a concern about this eating into sales of the new Boom Box.

I doubt that there is much crossover in sales. I don't think he cares about the caliber as much as he is annoyed Hornady didn't continue to back the 8.6 Blackout.

When I saw that video my immediate thought was that a bunch of dudes here were going to buy a 338 Arc just because he hates it

Billy Dixon would disagree

Well that was very.....unfiltered!

After doing a little digging, I came across this link:
https://soldiersystems.net/2024/10/17/pws-announces-support-for-the-hornady-338-arc-rifle-cartridge/
PWS is going to make a piston 16" and 12" (11.85").

There is some serious curve to that particular mag.  Not sure if the G-money mags would be better.

I also found a Silencer Shop article discussing the caliber.
https://www.silencershop.com/blog/338-arc
There were a couple of quotes in there that track with earlier thoughts:




This looks to be the a subsonic 200 yard hunting caliber that happens to shoot supers.  The inverse of 350 Legend.

With that in mind, I don't think 16" barrels make a lot of sense.  If you already have a suppressor, I don't think you are concerned about rifle/SBR laws.  And with braces back on the menu, shorter barrels would be the way to go if not SBR'd.  It isn't like you lose a lot of velocity with subs, and a shorter barrel would allow for a suppressor without becoming a musket.   But until someone comes up with some high performing bullets specifically for this caliber, you may have to write off the supersonic side as just expensive FMJ's for now, especially if using a shorter barrels.

I really find it hard to fathom there isnt more offerings in such a tiny niche application.

The next progression is going to a a 50bmg neutered and necked up to .75. We'll be doing cqb with sbr m82's.

Then all of a sudden we're gonna have subsonic Whitworth cannons.

I literally can't wait. So excited for the next evolution.

Curved mags are the Monkeypox of AR-15's

They need to design a mag around the ammunition and alter the magwell geometry like the Six8 or stop inventing ammunition for guns that don't exist.

How about a 20mm Vulcan shortened and necked up to .950?

Leaf through a copy of cartridges of the world or accrel sometime. If it can be done with a self-contained metallic cartridge, it's probably been done in some shape or other. Hell, about twenty years ago a group of guys on accrel came up with a series of cartridges based on a not then existent .390" caliber. Just for something new.

Need one of these with a holosun thermial on it.

Wrong, stabilization with 220s is erratic even out of a 9” with 1/7 or 1/8 twist. Does ok after about 10”

I really loved that round, and wish it had better support.

It’s now effectively dead, and it makes me a little sad.

Also, seems like lack of velocity is why most sub 300 BO rounds suck, minus the boutique stuff.

Aside from that not being my experience, and the bullets having a stability factor of 1.6, and the original SSK twist and the SAAMI twists being 1/8 and working with 220s for decades, tell me more?

Barrel length makes zero difference, twist is twist.  The only time it will be an issue is if the bullet is stripping in the rifling, and at that point you have other issues to contend with other than barrel length.  1:7 in 300 BLK will stabilize any bullet on the market you can fit in it and make it chamber.  1:5 isn't necessary at all.

In other cartridges velocity can matter a bit. Huge shifts. But in a subsonic blackout the difference between 950 and 1050 fps doesn’t matter.

As mentioned, in 300 BLK, that's simply not true for a few reasons.  One, the biggest factor in bullet stability vs twist is its physical length, not its weight.  Secondly, there isn't a bullet on the market that fits in 300 BLK rounds for an AR that won't stabilize well at 1:7 twist.  Lastly, barrel length doesn't matter, twist is twist.  A 7" barrel with 1:7 twist will spin a bullet the exact same RPM as a 16" barrel with 1:7 twist (assuming the bullets exit the barrels at the same velocity).  In terms of subs, then a little more twist than average is desirable since the velocities are so low, but once there, no more is needed.  Early AR's were 1:12 twist because they were shooting little 55 grainers at fast velocities.  The 1:9, 1:8 and then 1:7 only came later as longer and heavier bullets and subsonics became a thing.

This guy begs to differ:

https://www.youtube.com/watch?v=FzLn5o8-LcE