300 BLK Diet

[Uffdaphil]

My AAC 9” SBR felt in need of a diet so I ditched the Sopmod and tried four less bulky stocks. The SL-K looked to be The One until I remembered I had an old FiberLite that had never looked right on anything I built.

It looks okay on the AAC, but really works on the cheaper 8.3”. With the can it weighs less than the 9” upper without. As pictured the 8.3” is 6lbs 5.8 oz. A half pound less than with the upper upper and with the lighter rail and suppressor the balance is perfect.

P.S. Do you use shims on a direct thread suppressor? I am thinking it might help break free if left on a loong time.

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[Jerry R]

P.S. Do you use shims on a direct thread suppressor?

As best I recall (please correct me if wrong) AAC recommended not using shims on a direct attach. The can should not require timing, and a shim may introduce the possibility of a baffle strike.

[Former11B]

Shims would work better than a crush washer (always a no go) but the trick for direct thread cans is Teflon tape. I prefer the dark gray kind that’s for oily environments because 1) it’s darker in color and 2) it’s thicker and holds up better. Two passes around the threads and the can is held on nice and snug and no carbon lockup occurs. When it’s time to remove the can, just unscrew like normal and a gun cleaning toothbrush or a 9mm/.45 cal bore brush scrapes the threads clean for a new application of Teflon tape

[Uffdaphil]

Thanks Jerry. When I removed the Omega 9K I was surprised to find 4 shims. I have no recollection why I used them.

Former, that makes a lot of sense. I didn’t know there was other than white teflon tape.

[BoilerUp]

Shims would work better than a crush washer (always a no go) but the trick for direct thread cans is Teflon tape. I prefer the dark gray kind that’s for oily environments because 1) it’s darker in color and 2) it’s thicker and holds up better. Two passes around the threads and the can is held on nice and snug and no carbon lockup occurs. When it’s time to remove the can, just unscrew like normal and a gun cleaning toothbrush or a 9mm/.45 cal bore brush scrapes the threads clean for a new application of Teflon tape

Hmm, I wonder if that would be helpful even with thread taper lock / mounts.

[SINNER]

Use a few wraps of teflon tape on direct thread cans. Keeps them from loosening and allows easy removal. I use nothing but direct thread mounts now. Had enough of the QD bullshit.

[Uffdaphil]

Since I swap four taper mount cans around frequently, I’ll stick with anti-seize for those. The white Griffen goop is preferred to Aeroshell as it cleans off fingers more easily.

I used to have difficulty removing cans as I ignorantly thought you were supposed to unscrew while hot. Physics is not my strong suit.

[alamo5000]

Hmm, I wonder if that would be helpful even with thread taper lock / mounts.

No. It will prevent the can from seating all the way if you are putting it on that way and not just for the muzzle device.

Another option is Thread Sealant. It's a much better option vs the teflon tape.

[Joelski]

Since I swap four taper mount cans around frequently, I’ll stick with anti-seize for those. The white Griffen goop is preferred to Aeroshell as it cleans off fingers more easily.

I used to have difficulty removing cans as I ignorantly thought you were supposed to unscrew while hot. Physics is not my strong suit.

I forget the commercial name of the stuff Griffin uses and sells (because who doesn't have the technical term "Horse Gipe" rattling around in their head?).

I'd like to source a container of it for my own use because that stuff works like a charm. Aeroshell comes in grease gun cartridges and is nowhere near the cost people charge for a thimble size container.

[alamo5000]

I forget the commercial name of the stuff Griffin uses and sells (because who doesn't have the technical term "Horse Gipe" rattling around in their head?).

I'd like to source a container of it for my own use because that stuff works like a charm. Aeroshell comes in grease gun cartridges and is nowhere near the cost people charge for a thimble size container.

The stuff they use is called "ST-3A Thread Sealant" which is (I think) a trade name for a specific product-- sort of like "Kleenex".

https://www.ndindustries.com/product...-sealing/st-3/

I think the one they specifically use and/or repackage is specifically for Aerospace stuff, which means it's got a much higher temp rating. If I am not mistaken it's temp rated to over 700 degrees F but can still withstand much higher temps for short periods of time.

It's basically VibraTite but with a substantially higher temp range ability. It also does not 'set up' like a red loctite or Rocksett.

[Uffdaphil]

Griffin’s anti-seize is Lok-Cease 20/20.

[BoilerUp]

Well, according to GA's website, you are both right as they sell both Loc-Cease 20/20 and ST-3A but for different applications. Anti-Seize vs thread lock. They recommend Loc-Cease for the taper mounts and ST-3A for threaded interfaces like end-caps or loose direct thread.

[alamo5000]

On a side note, I tried 'thread sealant' for a couple of my suppressors. Specifically on the Revolution 9--the end cap is the critical part that puts tension on the baffle stack so I wanted to make sure that it didn't work loose or anything.

The stuff works, but man, it was a PITA to get it apart once its set. Basically I had to use solvents to get it to come apart. Basically it was like it was really carbon locked on there, except it was the thread sealant. Getting that end cap off was a multiple day ordeal of soaking and so forth. That being said I didn't know what to use to undo it so I tried a few options.

Another 'issue' is the end cap doesn't have anything you can put a wrench on so I was a bit limited there.

This is the stuff I used:

https://www.permatex.com/products/th...-sealant-6-ml/

[Uffdaphil]

“Up to 400 degrees” sounds too low for a suppressor. Maybe that Permatex was baked hard.

[SINNER]

I've literally worked with thread sealants for 35 years. Over 450-500° the carrier in pastes hardens and becomes a hard set thread sealer. If I absolutely had to use a paste based product the only one I'd use is nickel based antiseize. But as I stated before, Teflon tape is the correct choice. That's real world experience on systems thst reach 1200+° daily. The internet may say otherwise. LOL