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Posted: 5/27/2026 5:26:51 PM EDT
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Boy, I hope this isn't a stupid question... I bought an Omega 9K about 18 months ago, immediately dropped a SilencerCo AC2447 3-Lug Mount in, and put in on my MP5K clone because...MP5K. It's the perfect can for that gun. Life is good, and we shoot many, many rounds in suppressed bliss. Fast forward to today, and I want to try it on a pistol and go to drop a piston, spring, and AC504 spring retainer on and...no go. Won't even drop in. I look into the can and see this (sorry for the image quality): Attached File Attached File Holy crap, that looks suspiciously like a fixed barrel spacer (specifically the AC22) in the can, probably sitting in there since I got it. Questions: 1. Is that what I'm looking at? 2. What's the best way to get that sucker out? I already tried pulling it out with a hook with no luck. Assuming it is the FBS just sitting in there (carbon welded, no doubt), I'm considering soaking the can for a few days in Breakthrough Suppressor Cleaner to try and break the "weld." Maybe the ultrasonic. Thoughts? |
Don't let Perfection be the Enemy of Good
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| Looked at the manual? https://cdn.amplifi.pattern.com/3b6b14d9-0a17-42b4-b74b-150800c07b99 |
The plane flew, admit you're wrong and get over it.
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Originally Posted By Jakezor: Looked at the manual? https://cdn.amplifi.pattern.com/3b6b14d9-0a17-42b4-b74b-150800c07b99 Attached File |
Don't let Perfection be the Enemy of Good
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Except that isn't an Omega 9k in your pic, pretty sure it's an octane. Omega 9k is smooth and octane has the indents. Like someone else said you might have carbon and gunk build up where the piston should rest in there. The piston ears nestle into those notches near the end of the blast chamber. Clean those and try rotating the piston. You might have to press in a bit while threading in the captive piece. |
The plane flew, admit you're wrong and get over it.
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Originally Posted By Jakezor: Except that isn't an Omega 9k in your pic, pretty sure it's an octane. Omega 9k is smooth and octane has the indents. Like someone else said you might have carbon and gunk build up where the piston should rest in there. The piston ears nestle into those notches near the end of the blast chamber. Clean those and try rotating the piston. You might have to press in a bit while threading in the captive piece. Thanks. |
Don't let Perfection be the Enemy of Good
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Have a dental pick?  But really, the outer part of the blast chamber in you O9K looks similar to my Osprey45, and TBH similar to a fixed barrel spacer but it's wider. The spacer for fixed mount is about the same ID/OD as a piston spring, so if the piston spring fits in there your diameter should be ok. For the depth the piston will stick out the back at least a quarter inch if not a bit more, the spring compresses some so it has something to recoil against. |
The plane flew, admit you're wrong and get over it.
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Originally Posted By ScottS: Yup. This picture, too. https://www.ar15.com/media/mediaFiles/19800/Screenshot_2026-05-27_at_19-32-55_Fixed_-3769320.JPG Okay hopefully this makes sense via text since I’m on my mobile… but you at the end of the piston there are the little “spikes” that stick out. Now look in the suppressor at the end of the internal “cage” and you should see small gaps where those spikes interface That carbon on top of those gaps is what you need to knock off. It looks pretty thick, you might need to knock it off with a pick or a small screwdriver, I don’t think that’s coming off anytime soon in the ultrasonic cleaner |
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Originally Posted By dblazevich: Okay hopefully this makes sense via text since I'm on my mobile but you at the end of the piston there are the little "spikes" that stick out. Now look in the suppressor at the end of the internal "cage" and you should see small gaps where those spikes interface That carbon on top of those gaps is what you need to knock off. It looks pretty thick, you might need to knock it off with a pick or a small screwdriver, I don't think that's coming off anytime soon in the ultrasonic cleaner The teeth on the piston are too wide to fit past the "ridge" at the top of the blast chamber. It's not a matter of carbon build-up inside the "cage." When I get back to home I'll post a picture of the bottom of the piston compared to the top of the blast chamber, and also mic the two (bottom of the piston and ID of the "cage" Thanks. |
| That’s not the FBS inside the can. The Omega 9K has a fixed internal booster piston cage, unlike some other designs where the cage is removable from the suppressor body. It looks like it’s simply carboned up from all of the shooting with a tri lug with the muzzle blast just blasting into the inside of the cage. |
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Originally Posted By ECCO_Machine: What piston are you trying to install? The pistons for Griffin cans look identical to BPISTIN (SiCo/Rugged) pattern, but the flange is slightly larger. |
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Originally Posted By ScottS: This is what I'm starting to suspect, and that's why I'm headed to the caliper to make sure I have the right sized piston. I keep all the pistons organized in a small parts organizer, but...shit happens. Thanks to everyone for the help. |
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