I know the thunderbeast somewhat as a shop that I frequent loves them and I am in the back with the gunsmith often and have played around with them a good bit. I have heard they are awesome cans, especially in a precision application. If I were to make a guess I would think the sig is far more durable that the thunderbeast. The small tight threads on their QD have always looked fragile to me. The QD version is super light. As far as sound goes I have never shot them so I dont really have any good intel there. The guy at the shop, who doesn't seem to know a lot about the NFA, says they're SUPER quiet but he is shooting them on 556 which leads me to the conclusion he's clueless.
In regards to SIG CS, I delt with them once as I purchased a muzzle device second hand and the dude killed the crush washer between the muzzle device and the part that the can locks on to. I called and asked for another one. She was helpful and shipped one out free of charge.
The can is rock solid and I like the way it threads onto the QD. It has never locked up on me. I also like how you can swap from a break to a flash hider without removing the whole muzzle device. I am just waiting on SIG to come out with the double barrel break so i can run it on my SCAR 17.
If I was in the market for a new can I would be spending a lot of time researching the new Q cans. Kevin and the team killed it while at SIG. As a hunch I would believe they took it to the next level when they started Q. I was blown away with their quality at SHOT but didnt have the opportunity to shoot any of their cans.
This gun was designed to be a PDW. Barrel is X-Caliber based on recommendations from here. Its sub MOA if you put the work in and consistent 1 MOA in daily shooting. It has an adjustable gas block that is an SLR adjustable which does a great job of calming the back pressure bark. The gun is setup to fire supers of all types without the can (as a PDW) and will shoot anything with the can on.
You confirmed much of what I have been wondering about. For my planned can and carbine setup. For that, I thank you. Judging from your PDW we have similar ideas about 300 BO. I am fairly clueless though, but learning fast.
When you say put in the work speaking to barrel accuracy. Is that in regards to load development, or just trigger time at the range? I was on the fence about X cal, BA has a one MOA guarantee. After hearing your results I will probably go with X-cal. I will probably be doing the stainless steel, 1:7 twist with 5r rifling, and cyro. I want as much accuracy from the short barrel as I can get. I had much help from another smart individual in figuring this out.
What bolt carrier group did you use for your carbine? I was planning on using LMT or maybe JP, for the delayed unlocking time and enhanced bolt.
We came to the same conclusion on cans btw. I'd bet the Sig is more durable and just as quiet as the Ultra 9, due to it's wider tubeless design. Based from testimony here from members here, it has similar POI shift and repeatability. Sig Sauer was the only weakness, they didn't put enough follow though on the project, and slowed the whole process down. That is why I asked about customer service.
Kevin developed the can for Sig, then left and started his own company. By the time I am ready to Form 1 my lower and purchase my can, Q should have his rifle cans to market. I am fairly certain his cans well be better or dead even with Sig's. If not, it will be Sig or Thunderbeast