I recently purchased a new pistol can (Octane 45 HD) and am now playing the "NFA Wait" game. While I'm waiting, I'm trying to do my homework/research to educate myself on my best options as far as thread design/pitch for the host's barrel - which brings me to the purpose of this post/question.

Are there any advantages and disadvantages to the myriad of different barrel threads? Should I go with a standard right-hand threaded barrel or left-hand metric threads? As far as I can surmise, the .578x28 is a bit more common, but is a right-hand thread (which seems like it would tend to work loose while shooting). The M16x1L left-hand thread seems to be a bit less common, but (I'm guessing here) would be less likely to work loose while shooting.

I will have to purchase several barrels with whatever option I go with.

I would certainly appreciate any-and-all comments from folks who have experience with both [thread types].

Thanks in advance for your time and input.

Peace-Out,
Brad

Rats
Nobody has any suggestions/input?

Depends on what you want to shoot. "In this Country…" .45 ACP is .578 x 28, 40 S&W is 9/16 x 24, and 9mm and .22 are 1/2 x 28.


If you want to use it on a variety of hosts, you will end up with a variety of mounts.



*I* don't do metric. Some 'no compromise' types do. All depends on the platform.


Review the Handgun section for more info.

You asked for

BT8624 wrote:any-and-all comments from folks who have experience with both [thread types].

Many of us don't use metric. For experiences w RH thread, there isn't much worry with working loose. It would have to spin around several times before it began to wobble.

Friction helps hold threads in place. You shouldn't have to worry if threads are made to reasonable tolerance.

The biggest advantage metric threads have is providing a firmer grip on the barrel. They rarely come loose and back off while shooting. It's mainly thanks to the Viton o-rings that metric threads use. But a less often mentioned reason is their LH direction; you rotate clock-wise to tighten. Barrel rifling is mostly RH twist....the same direction as tightening metric threads. The bullet exit's rotational inertia on the barrel helps keep things snug.

Metric threads also index on the muzzle, instead of the barrel shoulder. This method usually ensures more accurate concentricity since it's more aligned with the bore.

With imperial threads (1/2x28, .578x28, etc) I usually have to re-snug the can fairly often. The threads come loose pretty easily. Whereas with metric threads they stay put for longer periods. Either way, it's always good practice to check a snug fit often.

rimshaker wrote:The biggest advantage metric threads have is providing a firmer grip on the barrel. They rarely come loose and back off while shooting. It's mainly thanks to the Viton o-rings that metric threads use. But a less often mentioned reason is their LH direction; you rotate clock-wise to tighten. Barrel rifling is mostly RH twist....the same direction as tightening metric threads. The bullet exit's rotational inertia on the barrel helps keep things snug.

LWD rifles their GLOCK barrel the opposite direction of whatever GLOCK does. I don't know why they do this, but it is contrary to the thread pattern, so that the twisting gases would theoretically retard the silencer unscrewing. Since I haven't shot either side-by-side, I can't swear that it matters at all. However, given the twist rate, a bullet might make only one full rotation before exiting the silencer regardless of twist direction... and is therefore a benefit on paper as opposed to practical application.

rimshaker wrote:The biggest advantage metric threads have is providing a firmer grip on the barrel. They rarely come loose and back off while shooting. It's mainly thanks to the Viton o-rings that metric threads use. But a less often mentioned reason is their LH direction; you rotate clock-wise to tighten. Barrel rifling is mostly RH twist....the same direction as tightening metric threads. The bullet exit's rotational inertia on the barrel helps keep things snug.

Metric threads also index on the muzzle, instead of the barrel shoulder. This method usually ensures more accurate concentricity since it's more aligned with the bore.

With imperial threads (1/2x28, .578x28, etc) I usually have to re-snug the can fairly often. The threads come loose pretty easily. Whereas with metric threads they stay put for longer periods. Either way, it's always good practice to check a snug fit often.

I have seen this mentioned frequently but from a mechanical ME 2001 course I
cannot see how one would get 'easier unwinding' from either
Imperial, Metric 60º, or ( gasp, old Jaguars ) Whitworth 55º angle, let alone
left hand threading.

Friction is friction, no? If one has a technical explanation I would be most
grateful.

Otherwise SCREW IT. [ Could I resist? ]

For machine bolts I would venture it's due to the pitch. Metric threads use finer pitches for comparable sizes, and a fine pitch thread will sit tighter for the same torque.

rimshaker wrote:The biggest advantage metric threads have is providing a firmer grip on the barrel. They rarely come loose and back off while shooting. It's mainly thanks to the Viton o-rings that metric threads use. But a less often mentioned reason is their LH direction; you rotate clock-wise to tighten. Barrel rifling is mostly RH twist....the same direction as tightening metric threads. The bullet exit's rotational inertia on the barrel helps keep things snug.

Metric threads also index on the muzzle, instead of the barrel shoulder. This method usually ensures more accurate concentricity since it's more aligned with the bore.

With imperial threads (1/2x28, .578x28, etc) I usually have to re-snug the can fairly often. The threads come loose pretty easily. Whereas with metric threads they stay put for longer periods. Either way, it's always good practice to check a snug fit often.

Hi Rim,
This is kind of what I was getting at. It seems like the torque from the bullet rotation would tend to snug-up the left hand threaded can.
I own a .22 Sparrow with the typical 1/2x28 RH threads and have to regularly snug it up while shooting.
I was wondering if a LH threaded can would require the same.

I have rh and left hand, they both work loose, Osprey 9 on G17 and Sig 2022.

BT8624 wrote:This is kind of what I was getting at. It seems like the torque from the bullet rotation would tend to snug-up the left hand threaded can.
I own a .22 Sparrow with the typical 1/2x28 RH threads and have to regularly snug it up while shooting.
I was wondering if a LH threaded can would require the same.

The Sparrow and Spectre thread specs are like a hybrid between metric and imperial. A longer 1/2x28 RH cut that also engages an o-ring.

Are you using a barrel with just regular 1/2x28 threads? My Sparrow doesn't come loose on hosts that have the o-ring cut.

The rotational bullet inertia idea is mostly theoretical. Too hard to prove factually, but makes common sense. The effects are probably miniscule anyway. Like I said, it's primarily the o-rings that provide the snug fits.

I can't even count my threaded barrels but they are all right hand and common threads for caliber. Makes it easy and simple and interchangeable. ( KISS)

Don't have a Sparrow or Spectre so no " special" threading needed for 22 .

Have a few centerfire pistols that might come lose now and then but usually after a good thread cleaning. You can use Teflon tape or a 1/4 drop of LT blue if having issues.

I can tell you that from my experience, LH threads are a complete pain in the a$$....at least with the Octane 9 HD 2. I was actually on here searching for a solution when I came across this thread.

I have a P226 with 13.5 LH threads and the Octane 9 HD 2 suppressor I have comes loose every 5 or 6 rounds like every suppressor seems to do. I do a slight tightening and when I do that, the spring retainer which is threaded the opposite direction comes loose. This makes tightening the suppressor on the piston impossible and also affects my POI. So I have to break out a wrench and tighten the spring retainer as tight as possible and only then can I tighten the can on the barrel. When the can heats up after about 40 to 50 rounds, this becomes an impossible task and I put the can away, it's too much of a pain to even shoot any longer.

I'm desperate enough that I went ahead and spent an extremely painful amount (over $400!) to order a Bar-Sto barrel for the P226 that has RH threads. But it was either that or the Octane 9 HD 2 is worthless. With RH threads, both the piston and spring retainer tighten together and solve the problem. I had RH threads on a glock 19/Lone Wolf setup and it was a pleasure to shoot since this RH threading wasn't a problem. I could do the occasional can tightening on the barrel threads and my POI never changed . The problem with the Glock 19 is that it is VERY loud compared to the P226. Enough to make my ears ring.

mikesmith82 wrote:I can tell you that from my experience, LH threads are a complete pain in the a$$....at least with the Octane 9 HD 2. I was actually on here searching for a solution when I came across this thread.

I have a P226 with 13.5 LH threads and the Octane 9 HD 2 suppressor I have comes loose every 5 or 6 rounds like every suppressor seems to do. I do a slight tightening and when I do that, the spring retainer which is threaded the opposite direction comes loose. This makes tightening the suppressor on the piston impossible and also affects my POI. So I have to break out a wrench and tighten the spring retainer as tight as possible and only then can I tighten the can on the barrel. When the can heats up after about 40 to 50 rounds, this becomes an impossible task and I put the can away, it's too much of a pain to even shoot any longer.

I'm desperate enough that I went ahead and spent an extremely painful amount (over $400!) to order a Bar-Sto barrel for the P226 that has RH threads. But it was either that or the Octane 9 HD 2 is worthless. With RH threads, both the piston and spring retainer tighten together and solve the problem. I had RH threads on a glock 19/Lone Wolf setup and it was a pleasure to shoot since this RH threading wasn't a problem. I could do the occasional can tightening on the barrel threads and my POI never changed . The problem with the Glock 19 is that it is VERY loud compared to the P226. Enough to make my ears ring.

Hmmph, never had a problem with LH threads.

Bendersquint wrote:

mikesmith82 wrote:I can tell you that from my experience, LH threads are a complete pain in the a$$....at least with the Octane 9 HD 2. I was actually on here searching for a solution when I came across this thread.

I have a P226 with 13.5 LH threads and the Octane 9 HD 2 suppressor I have comes loose every 5 or 6 rounds like every suppressor seems to do. I do a slight tightening and when I do that, the spring retainer which is threaded the opposite direction comes loose. This makes tightening the suppressor on the piston impossible and also affects my POI. So I have to break out a wrench and tighten the spring retainer as tight as possible and only then can I tighten the can on the barrel. When the can heats up after about 40 to 50 rounds, this becomes an impossible task and I put the can away, it's too much of a pain to even shoot any longer.

I'm desperate enough that I went ahead and spent an extremely painful amount (over $400!) to order a Bar-Sto barrel for the P226 that has RH threads. But it was either that or the Octane 9 HD 2 is worthless. With RH threads, both the piston and spring retainer tighten together and solve the problem. I had RH threads on a glock 19/Lone Wolf setup and it was a pleasure to shoot since this RH threading wasn't a problem. I could do the occasional can tightening on the barrel threads and my POI never changed . The problem with the Glock 19 is that it is VERY loud compared to the P226. Enough to make my ears ring.

Hmmph, never had a problem with LH threads.

Same here. In fact, I prefer them.

Flipz wrote:

Bendersquint wrote:

mikesmith82 wrote:I can tell you that from my experience, LH threads are a complete pain in the a$$....at least with the Octane 9 HD 2. I was actually on here searching for a solution when I came across this thread.

I have a P226 with 13.5 LH threads and the Octane 9 HD 2 suppressor I have comes loose every 5 or 6 rounds like every suppressor seems to do. I do a slight tightening and when I do that, the spring retainer which is threaded the opposite direction comes loose. This makes tightening the suppressor on the piston impossible and also affects my POI. So I have to break out a wrench and tighten the spring retainer as tight as possible and only then can I tighten the can on the barrel. When the can heats up after about 40 to 50 rounds, this becomes an impossible task and I put the can away, it's too much of a pain to even shoot any longer.

I'm desperate enough that I went ahead and spent an extremely painful amount (over $400!) to order a Bar-Sto barrel for the P226 that has RH threads. But it was either that or the Octane 9 HD 2 is worthless. With RH threads, both the piston and spring retainer tighten together and solve the problem. I had RH threads on a glock 19/Lone Wolf setup and it was a pleasure to shoot since this RH threading wasn't a problem. I could do the occasional can tightening on the barrel threads and my POI never changed . The problem with the Glock 19 is that it is VERY loud compared to the P226. Enough to make my ears ring.

Hmmph, never had a problem with LH threads.

Same here. In fact, I prefer them.

To the two posts previous to this one, what cans do you use? If this is uncommon and it turns out that this can be fixed, I'll be one happy camper.

mikesmith82 wrote:I can tell you that from my experience, LH threads are a complete pain in the a$$....at least with the Octane 9 HD 2. I was actually on here searching for a solution when I came across this thread.

I have a P226 with 13.5 LH threads and the Octane 9 HD 2 suppressor I have comes loose every 5 or 6 rounds like every suppressor seems to do. I do a slight tightening and when I do that, the spring retainer which is threaded the opposite direction comes loose. This makes tightening the suppressor on the piston impossible and also affects my POI. So I have to break out a wrench and tighten the spring retainer as tight as possible and only then can I tighten the can on the barrel. When the can heats up after about 40 to 50 rounds, this becomes an impossible task and I put the can away, it's too much of a pain to even shoot any longer.

I'm desperate enough that I went ahead and spent an extremely painful amount (over $400!) to order a Bar-Sto barrel for the P226 that has RH threads. But it was either that or the Octane 9 HD 2 is worthless. With RH threads, both the piston and spring retainer tighten together and solve the problem. I had RH threads on a glock 19/Lone Wolf setup and it was a pleasure to shoot since this RH threading wasn't a problem. I could do the occasional can tightening on the barrel threads and my POI never changed . The problem with the Glock 19 is that it is VERY loud compared to the P226. Enough to make my ears ring.

Trying to keep the booster tight on a Liberty Mystic (right hand threads) on a HK USP 9mm SD factory left hand barrel is a pain in the rear.

So much so, I'm shopping for a new host. With Right Hand threads.