suppressor came loose this weekend

[plant.one]

so how would ya'll suggest i go about correcting my potential tailcap/barrel thread fitment issue as a more long term/permanent solution?

would i be better served to get a new (nonthreaded) tailcap and have ADCO cut a matching female thread that they put on the barrel in it?

Is ADCO licensed to make silencer parts?

ok so if option b isnt practical, back to the original question - what would you suggest as a longer term solution to the problem?

[plant.one]

and if the threaded adapters themselves are considered silencer parts - how can anyone with a credit card buy one for a silencerco harvester on midway.

https://www.midwayusa.com/product/76941 ... read-mount

theres no restrictions listed anywhere i can find on midway and other sites saying that those type items have any NFA rules associated with them.


so how would a gunsmith need to be liscenced to produce a direct thread adapter for my needs?



i'm just trying to understand the limitations of the box i currently appear to find myself within

[dellet]

I told you be before, Rocksett or Tig.

I probably would not do anything more than anti-seize and pay more attention to when/if it comes loose again. You said it was a full turn and no loss in accuracy until the last shot, it didn't back off a half turn on the last shot. That would indicate the threads are reasonably tight, because you likely ran a whole mag through it loose.

Something I brought up earlier was barrel diameter where the mount seats. If that is small, an option is going from direct thread to a mount, the mount could be glued on. A long can, no matter how light, will be more likely to vibrate loose if it has a small contact area.

I assume this is not the first time you used this setup, has it come loose before? What were you doing different?

[dellet]

and if the threaded adapters themselves are considered silencer parts - how can anyone with a credit card buy one for a silencerco harvester on midway.

https://www.midwayusa.com/product/76941 ... read-mount

theres no restrictions listed anywhere i can find on midway and other sites saying that those type items have any NFA rules associated with them.


so how would a gunsmith need to be liscenced to produce a direct thread adapter for my needs?



i'm just trying to understand the limitations of the box i currently appear to find myself within

I guess that's the difference between a threaded adapter and an endcap???????

[plant.one]

I told you be before, Rocksett or Tig.

I probably would not do anything more than anti-seize and pay more attention to when/if it comes loose again. You said it was a full turn and no loss in accuracy until the last shot, it didn't back off a half turn on the last shot. That would indicate the threads are reasonably tight, because you likely ran a whole mag through it loose.

the loss of accuracy happened while another shooter was behind the trigger. i originally attributed it to rushed/sloppy shooting, so i took a couple shots after they had a few misses and thats when i saw the in the dirt impact several feet below the target that triggered the "ok wait a minute" moment when i then discovered the loose can. as you said its likely it was at least a full mag shot when loose. no way to know exactly.

Something I brought up earlier was barrel diameter where the mount seats. If that is small, an option is going from direct thread to a mount, the mount could be glued on. A long can, no matter how light, will be more likely to vibrate loose if it has a small contact area.

the barrel diamater at the shoulder of the threaded area is .850. its a varmit taper heavy barrel with a .920 gas block journal. there's some play to it until it tightens down against the shoulder. but nothing that would strike me as out of the ordinary based on other muzzle devices i have on other barrels (STD's, my rimfire can, basic thread protectors, etc)

I assume this is not the first time you used this setup, has it come loose before? What were you doing different?

its not the first time its come loose, but never like this. usually after a few shots (lets say 10-15) i ensure that its snug and then i'm good for the session. usually it needs a little more at the snug check, sometimes its fine. but thats with any firearm i put this can on, not necessarily this barrel/upper or even that specific tailcap. my sparrow is the same way. thread it on, take a few shots, check for snug, tighten it up and then go to town. its a check i routinely perform when shooting suppressed (which is almost all my shooting these days) and have since i got my sparrow almost 5 years ago. the amount of ammo shot was consistent with a normal session, even a little on the low side (i only had about 150 rounds with me that day), etc.

I guess that's the difference between a threaded adapter and an endcap???????

maybe i'm incorrectly labeling what i'm calling it as part of this discussion. please let me clarify

what i'm calling an "endcap" is on the front of my suppressor. it has no internal threads on it. just a hole for the bullet to come out of. i'm not worried about the endcap - i dont wish to change it in any way, shape or form - nor do i think i could if i wished to anyway now due to the strike. i'm inquiring about options for the tailcap, the part that threads onto the barrel.

what i'm calling a "tailcap" performs the exact same mechanical function as the harvester "thread adapter". It has external threads that mate to the ID thread of the main tube body of my suppressor, and internal threads to match the threads on my barrel(s). its not permanently affixed to the suppressor tube in any way. i could leave them attached to my barrels and thread the suppressor onto it if i choose (but it would look dumb as hell with a 1.5" OD piece attached as a thread protector type device). just like the harvester - my can was/is designed to utilize multiple rear adapters to allow for use on 30 caliber or under firearms. just like the harvester, the mounts i could utilize would all have the same external thread pattern, but offer varying internal mounting options (different threads, or various QD attach adapters).

[dellet]

The barrel diameter is large enough to give adequate support, what you might check is to make sure there is full contact between the mating surfaces. You've shot it enough so there will be a wear mark like a half moon if it's not.

Torque loss as the barrel heats up is not all that uncommon as you said. Dissimilar metals can/will do that. That's why Loctite was invented, to provide holding power to low torque, high vibration applications.

As far as your cap goes, I believe Silencerco took the time to have ATF make a ruling on replaceable caps. Think Sigbrace and Deadair suppressor wipes or Neilsen device.

Not saying I know the answer but, if I owned a business and some one asked me to make an end/tail cap for their converted flashlight suppressor I know exactly what my answer would be.

There has been a couple of raids in the last year of these "solvent trap" sellers. What got them in trouble was either having converted parts on hand, or having instructions of how to convert the parts for use in suppressors. Not a line I would walk.

But back to the question, I would try Anti-seize and see what happens.

[certifiable]

For direct thread cans on semi autos I like to use viton o-rings to keep the cans tight.
An ASA p/n 568-011 works well for 1/2" threads and 568-016 for 5/8", both have 1/16" cross section.
Rubber o-rings won't last but viton o-rings are designed for high temp/pressure applications.
Cheap option without the mess, need for a welder or pissing the gf off

[392heminut]

T

As far as your cap goes, I believe Silencerco took the time to have ATF make a ruling on replaceable caps. Think Sigbrace and Deadair suppressor wipes or Neilsen device.

Replaceable end caps are legal as long as they don't act as retainers for the internal parts. Anything that acts as a retainer of the internals is considered a part of the suppressor and cannot be legally changed by anyone but a licensed manufacturer. An endcap that doesn't retain any internal parts is regarded the same as an adapter or booster.

[dellet]

T

As far as your cap goes, I believe Silencerco took the time to have ATF make a ruling on replaceable caps. Think Sigbrace and Deadair suppressor wipes or Neilsen device.

Replaceable end caps are legal as long as they don't act as retainers for the internal parts. Anything that acts as a retainer of the internals is considered a part of the suppressor and cannot be legally changed by anyone but a licensed manufacturer. An endcap that doesn't retain any internal parts is regarded the same as an adapter or booster.

So thinking about an Octane 9. Remove the rear cap to replace the piston, I could replace that cap,as well as the spring and booster.

The front cap is removed to remove the baffles, that cap is a "regulated part".

If the baffles did not come out, then I could have mulitple caps, of different bore/calibers and even though they technically change the caliber of the suppressor, they're fine.

I guess because it's technically a tax law, it has to be confusing