"Over Tightening" is a Problem?

[308pirate]

If the barrel has right hand twist, and so do the threads going from the other direction, tightening a muzzle device too much actually opens the bore

There's no way that can be right. The shit people come up with LOL

 

[secondofangle2]

Go finish your homework son and report back after it’s been checked

 

[carbonbased]

However, with thunder beast adapters, I have been told to absolutely slather it with 272 Loctite or else the can can seize upon the break and you will turn off your break when you try to remove the can with a strap wrench if it gets seized up.

Hmmmm good to know. Thinking of buying a CF TBAC. Thx.

 

[Cascade Hemi]

However, with thunder beast adapters, I have been told to absolutely slather it with 272 Loctite or else the can can seize upon the break and you will turn off your break when you try to remove the can with a strap wrench if it gets seized up. I know this because I had to send in my 338 ultra can, and not even thunder beast could get the break out of it so they had to machine it out on a lathe. I also now use high temperature anti-size on my thunder beast cans, so this doesn’t happen again

TBAC would have less issues if they had a torque spec called out that was greater than hand tight. They are relying on an adhesive that breaks down with heat and moisture, both of which are present inside silencers.

 

[Supersubes]

TBAC would have less issues if they had a torque spec called out that was greater than hand tight. They are relying on an adhesive that breaks down with heat and moisture, both of which are present inside silencers.

I think the issue is a muzzle device thats very sensitive to carbon locking.

 

[Cascade Hemi]

I think the issue is a muzzle device thats very sensitive to carbon locking.

That certainly doesn't help but when the muzzle device spins off by hand there's a good indication that adhesive alone isn't sufficient for retention to the barrel.

 

[Supersubes]

That certainly doesn't help but when the muzzle device spins off by hand there's a good indication that adhesive alone isn't sufficient for retention to the barrel.

Is that something tbac wrote somewhere? Cant imagine anyone actually doing that. Im talking about hand tight with thread locker.

 

[Cascade Hemi]

Is that something tbac wrote somewhere? Cant imagine anyone actually doing that. Im talking about hand tight with thread locker.

Here's their video. He uses a crescent wrench but states it doesn't need to be "that tight, that's what loctite is for".

 

[AMGtuned]

Rocksett or red loctite. I rocksett my can adapters in. I certainly don't use a torque wrench on a proximal adapter. Thread locker, tighten until comfortable, voila.

I also thread lock muzzle devices. As stated already above, it sucks to peel one off inside a can. NEVER use crush washers on a muzzle device intended for suppressor use. Timing shims. Thread locker, torque to desired spec (can't imagine that's more than 30-60 ft-lb), done again.

Don't use Thread locker between the 2.

Buy quality gear, and the tolerance stacking where your concern is, is minimal. I'd bet there are more non-concentric barrels floating around, than MD's and adapters these days

 

[mebgardner]

Here's their video. He uses a crescent wrench but states it doesn't need to be "that tight, that's what loctite is for".

That's a great video. He also speaks to another major point of this thread, over torque and the effect on accuracy (@ 4:40). Watching him work explains so much.

Thanks for posting this.

 

[308pirate]

Go finish your homework son and report back after it’s been checked

Let me be more blunt. It's bullshit and I dare you to prove it with actual measurements.

 

[mebgardner]

Muzzle device torque on the barrel threads can constrict the bore at the muzzle. How much constriction would depend on the torque value and the size of the threads in relation to the bore.

That posted video goes a long way to validating @msgriff statement. He called it "trumpeting" (@ 4:40).

I don't know how much torque was being applied to the muzzle device while he was using the crescent wrench. I'm guessing 20 ftlbs thereabouts as he finished his last go? Not alot anyway, thats my point.

He described the amount of loctite he used as "generous". His use describes his view of a "generous" amount.

Great video.

 

[ma smith]

Go finish your homework son and report back after it’s been checked

Note that elongation typically results in 'transverse compression', which is a reduction in diameter.
See, eg diagram below...

source, is circa 22 min>

 

[ma smith]

And...

Here's a diagram discussing elongation forces on a threaded joint

 

[Arc Light]

You guys might find this article interesting.

https://bulletin.accurateshooter.com/2022/11/for-optimal-accuracy-with-threaded-muzzle-barrels-use-larger-muzzle-thread-diameter/

 

[Cascade Hemi]

You guys might find this article interesting.

https://bulletin.accurateshooter.com/2022/11/for-optimal-accuracy-with-threaded-muzzle-barrels-use-larger-muzzle-thread-diameter/

That article says threading alone opens the bore.

 

[Arc Light]

That article says threading alone opens the bore.

Yep. And why I always thread my barrels a minimum of 5/8-24, or bigger, regardless of caliber.

 

[Cascade Hemi]

Yep. And why I always thread my barrels a minimum of 5/8-24, or bigger, regardless of caliber.

That article said 5/8-24 threading alone opens up the bore.

 

[secondofangle2]

Look at the diagrams above and see where the “tightening” or “trumpeting” is in relation to the muzzle.

You want the muzzle to be perfect on caliber with the preceding bore, or tighter. If it trumpets, the muzzle is looser, relatively. Not good.

But you do you

 

[Arc Light]

That article said 5/8-24 threading alone opens up the bore.

That's true, but some barrels 5/8" threads are the biggest I could do due to barrel size. I prefer 3/4" threads when possible.

 

[ma smith]

Look at the diagrams above and see where the “tightening” or “trumpeting” is in relation to the muzzle.

IE "its not an actual opening, but a return to normal after the choke"?

 

[secondofangle2]

If we all went slightly gain twist, all of this would be moot

 

[mebgardner]

Rocksett or red loctite. I rocksett my can adapters in. I certainly don't use a torque wrench on a proximal adapter. Thread locker, tighten until comfortable, voila.

I also thread lock muzzle devices. As stated already above, it sucks to peel one off inside a can. NEVER use crush washers on a muzzle device intended for suppressor use. Timing shims. Thread locker, torque to desired spec (can't imagine that's more than 30-60 ft-lb), done again.

Don't use Thread locker between the 2.

Buy quality gear, and the tolerance stacking where your concern is, is minimal. I'd bet there are more non-concentric barrels floating around, than MD's and adapters these days

Thanks. No crush washers, OK. Are you good with peel washers? I have and have used, timing shim sets. But I see peel washers being used in the video posted, and frankly it's first time I've see them being used. I've heard of them, I've handled systems that have them installed, and peel has been around for a very long time. I've just never seen an armorer use them is all. Everyone seems to recommend timing shims, so I'm just checking in here.

 

[AMGtuned]

Thanks. No crush washers, OK. Are you good with peel washers? I have and have used, timing shim sets. But I see peel washers being used in the video posted, and frankly it's first time I've see them being used. I've heard of them, I've handled systems that have them installed, and peel has been around for a very long time. I've just never seen an armorer use them is all. Everyone seems to recommend timing shims, so I'm just checking in here.

I've personally only used timing shims. Can't imagine they're much different. Take that for what you paid for it.

If the guys at TBAC run them, I would. But I'm not gonna throw away my shims just to switch. Can always make one in the lathe if I had to also

 

[msgriff]

Thanks. No crush washers, OK. Are you good with peel washers? I have and have used, timing shim sets. But I see peel washers being used in the video posted, and frankly it's first time I've see them being used. I've heard of them, I've handled systems that have them installed, and peel has been around for a very long time. I've just never seen an armorer use them is all. Everyone seems to recommend timing shims, so I'm just checking in here.

Not who you asked, but it mostly comes down to personal preference.
Like said in the video, peel washers come in 0.002" layers, which for 24 TPI is around 18 degrees or 3 minutes on a clock face of timing per layer.
With many shim sets, the thinnest shim is 0.003" or 0.004", but there are some kits (Precision Reflex) that go down to 0.002". If you're pulling from multiple PR shim kits, you can usually get down to within 0.001" difference in thickness in your final shim stack.
There's also Accu-Washers, which come in 20 degree increments. Not much difference over peel for final torque, but you start out at a thicker minimum shim (0.060"), so you may lose more than 1 complete rotation of MD thread engagement before it's timed. Not a function issue, more of an appearance thing.
Another thing to consider is the OD of your timing method choice, but once again, not a function issue. Same with the color of your timing method, some don't like to see stainless steel shims on their black barrel/MD.