Mini-14 barrel thread shoulder can't mount a sound suppressor?

I have a 580+ Mini-14 5.56 Tactical 16 in with threaded muzzle.

I've read the shoulder after the threads is tapered, not squared, so a suppressor or suppressor adapter won't mount concentrically and would lead to a baffle strike.

Is this true? I haven't removed the factory flash suppressor on mine because it's on there pretty tight.

Is this mounting issue a possibility or definite?

Would a gunsmith have to remove the barrel to square the mounting shoulder?

Complete nonsense. If the threading on the barrel is correct, you're fine. We've fired suppressors that wouldn't thread on all the way due to carbon fouling on the threads and had no problems.

You could use shims for either a mount or direct thread can too so you ensure a mating surface between the barrel and can/mount. Thats what I'd do. Removing the radius is not an option in my opinion.

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Originally Posted by markm

Complete nonsense. If the threading on the barrel is correct, you're fine. We've fired suppressors that wouldn't thread on all the way due to carbon fouling on the threads and had no problems.

You could use shims for either a mount or direct thread can too so you ensure a mating surface between the barrel and can/mount. Thats what I'd do. Removing the radius is not an option in my opinion.

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This is good news!

I don't quite understand the shims, though. Where would they go? Do you mean a washer or crush washer or something else?

Shims are a higher quality washer that are often used for timing suppressor mounts. The inner diameter of the shim should be wider than the radius between the threads and barrel shoulder. I have had thin shims that bend over the radius too. Just need enough to get shoulder to mount or suppressor contact.

Since you can't bore sight check alignment on a mini, I'd put a cleaning rod int he bore and get an idea that things roughly are in alignment.

IDK about the threads, but minis are so grossly over-gassed from the factory that you're gonna need port bushings or an adjustable gas block to keep it from beating itself to death when run suppressed.

Adjustable Gas Block
Bushing Kit

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Originally Posted by kerplode

IDK about the threads, but minis are so grossly over-gassed from the factory that you're gonna need port bushings or an adjustable gas block to keep it from beating itself to death when run suppressed.

Adjustable Gas Block
Bushing Kit

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I considered that.

The 18 in & 16 in get the same factory bushing, so the 16 in isn't as overgassed as the 18.

Also, I'm considering either a small can, like a Turbo K, or one of the "reduced" blowback cans.

Also, despite the .223 Wylde chamber in the Mini being compatible with .223 & 5.56 many have learned .223 is more reliable and that's what I use. Also means less gas.

And, if I must, I can install one of the reduced-size gas bushings.

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Originally Posted by markm

Shims are a higher quality washer that are often used for timing suppressor mounts. The inner diameter of the shim should be wider than the radius between the threads and barrel shoulder. I have had thin shims that bend over the radius too. Just need enough to get shoulder to mount or suppressor contact.

Since you can't bore sight check alignment on a mini, I'd put a cleaning rod int he bore and get an idea that things roughly are in alignment.

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I'll do some further reading about that, thanks!

Quote:

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Originally Posted by kerplode

IDK about the threads, but minis are so grossly over-gassed from the factory that you're gonna need port bushings or an adjustable gas block to keep it from beating itself to death when run suppressed.

Adjustable Gas Block
Bushing Kit

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Can they possibly be worse than an AK series suppressed? Maybe Kalashnikovs are a bit more rugged.

Quote:

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Originally Posted by markm

Shims are a higher quality washer that are often used for timing suppressor mounts. The inner diameter of the shim should be wider than the radius between the threads and barrel shoulder. I have had thin shims that bend over the radius too. Just need enough to get shoulder to mount or suppressor contact.

Since you can't bore sight check alignment on a mini, I'd put a cleaning rod int he bore and get an idea that things roughly are in alignment.

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I know what radius and diameter are but I still don't understand.

The Mini-14 Tactical thread shoulder isn't square on the 5.56. (But is on a .300 blk version)

I found "shoulder rings" that resolve this issue on Scar 16's & Tavor's. Will they work my Mini?

I should have the flash hider mount included with the can shortly. I want to get that mounted so I can enjoy congecal visits with my suppressor.

Attachment 70680

Here is a bad picture of the bare muzzle.

There isn't much of a shoulder. And it's tapered, not squared off like a .300 BLK Mini-14. Threads are 5/8 in x24.

My can will come with a flash hider. (556K-FLOW) What shoulder ring do I need to mount the can nice and straight?