How hot does a barrel get?

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CharlieBravo
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How hot does a barrel get?

Post by CharlieBravo » Mon Aug 06, 2012 11:57 pm

I want to use a Teflon (PTFE) bushing to center a reflex can on a semiauto .308, I'm wondering how hot the barrel gets, Teflon starts to melt at 620 degrees Fahrenheit (327 Celsius).
I'd like to do some rapid semi auto fire, drills with 5-10 shots at a time.

Does anyone know if Teflon bushings might work? All comments welcome, thanks!

P.S. teflon autoignites at 1027 degrees F but I think that's irrellevant even with full auto mag dumps, or am I mistaken?

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Bendersquint
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Re: How hot does a barrel get?

Post by Bendersquint » Tue Aug 07, 2012 12:47 am

CharlieBravo wrote:I want to use a Teflon (PTFE) bushing to center a reflex can on a semiauto .308, I'm wondering how hot the barrel gets, Teflon starts to melt at 620 degrees Fahrenheit (327 Celsius).
I'd like to do some rapid semi auto fire, drills with 5-10 shots at a time.

Does anyone know if Teflon bushings might work? All comments welcome, thanks!

P.S. teflon autoignites at 1027 degrees F but I think that's irrellevant even with full auto mag dumps, or am I mistaken?
This is not a smart idea, especially when it comes to silencers. Heat is not the only problem, you have to worry about compression as well.

5-10 shot drills will up the temp of the can FAST.

Use metal in a silencer not plastic. There is a reason no commercial silencer use plastic, especially on a critical point like that.

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Re: How hot does a barrel get?

Post by CharlieBravo » Tue Aug 07, 2012 11:09 am

Bendersquint: The bushing would be located outside the can, ie no pressure. Do you know how hot it gets?

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rogerme
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Re: How hot does a barrel get?

Post by rogerme » Tue Aug 07, 2012 11:42 am

CharlieBravo wrote:Bendersquint: The bushing would be located outside the can, ie no pressure. Do you know how hot it gets?

Volcano hot.

Even outside the suppressor it could melt or burst into flames.
"If you carry a gun, people call you paranoid. That's ridiculous. If I have a gun, what in the hell do I have to be paranoid about?"

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CharlieBravo
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Re: How hot does a barrel get?

Post by CharlieBravo » Tue Aug 07, 2012 1:16 pm

I searched again using Google and other terms this time and this thread gave me specific info:
http://www.silencertests.com/forum/view ... 5a&start=0

This might be of help to someone else, thanks again Silencertalk!

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renegade
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Re: How hot does a barrel get?

Post by renegade » Tue Aug 07, 2012 1:17 pm

A lot depends upon your rate of fire, type, length of BBL.

On a 5.56 HBAR 14.5/M855:

One shot per minute, maybe 300 degrees.

C-Mag Full/Auto Dump with Silencer? I have measured over 1200 degrees.

Have not measured a 308.

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Re: How hot does a barrel get?

Post by CharlieBravo » Tue Aug 07, 2012 1:29 pm

Awesome, thanks Renegade!
That means Teflon is out, back to the drawing board.

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Re: How hot does a barrel get?

Post by renegade » Tue Aug 07, 2012 1:34 pm

CharlieBravo wrote:Awesome, thanks Renegade!
That means Teflon is out, back to the drawing board.
Yes, Not the same as your plan, but I once made the mistake of using Teflon Tape to tighten up some loose threads. Bad Idea. Sticky Mess.

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rogerme
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Re: How hot does a barrel get?

Post by rogerme » Tue Aug 07, 2012 4:42 pm

The important thing here is if you shoot more then a few rounds through a 5.56 quickly do NOT touch the suppressor. Also if on a single point sling do not let it hang while you bend over (while wearing shorts) and let it touch your leg! After 30 rounds on FA this HURTS really bad..
"If you carry a gun, people call you paranoid. That's ridiculous. If I have a gun, what in the hell do I have to be paranoid about?"

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Re: How hot does a barrel get?

Post by CharlieBravo » Tue Aug 07, 2012 7:32 pm

:lol: Did it leave a mark? I burnt my fingers, that was enough for me.

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Re: How hot does a barrel get?

Post by twodollarbill » Tue Aug 07, 2012 7:52 pm

My 1980's AWC M-22 suppressor uses a tapered Brass collet to help center, stabilize the rear mount.
The slots in the collet allow the collet to snug up tight on the barrel when being pushed into the matching taper of the
rear mount when the rear cap is screwed on.

If I was making a reflex type suppressor designed with a rear "bushing"........I'd make the "bushing" out of Brass.

Image

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Re: How hot does a barrel get?

Post by CharlieBravo » Tue Aug 07, 2012 8:41 pm

Twodollarbill: That's awesome, I was just thinking of doing something more like a collet, now I don't need to visualize it in my head, thanks for that picture!

I was also thinking brass, then I started wondering if I could do it in stainless steel, I have both 304 and 316 available. I need it to slip over the barrel without scraping off the finish. Once in place, resting against the thicker part of the barrel it would be tensioned down when I tighten the flashider threads.

I guess I have to try it out, both with ss and brass, I just wish I could get it right the first time. Both metals look a lot better than teflon, that's for sure!

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Wicked
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Re: How hot does a barrel get?

Post by Wicked » Tue Aug 07, 2012 9:55 pm

Not sure how correct this is: but an old Navy instructor told me that a 5.56 M4 profile barrel increased + 7 deg. F with every round fired. Heavy barrels would heat up slower and also cool slower I would assume? Temperature of the barrel would really depend on the firing schedule. A 30 rd magazine fired continuously on a 90 deg. summer day would get the barrel to 300 deg. like right now. Dump just one more mag, and you're looking at 500 deg F.


Can anyone verify or correct this 7 deg. data?
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Re: How hot does a barrel get?

Post by Bendersquint » Tue Aug 07, 2012 10:06 pm

There is a reason why the bushing is in brass.

Why does everyone always want to reinvent the wheel when it works great as it is?

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Re: How hot does a barrel get?

Post by Bendersquint » Tue Aug 07, 2012 11:23 pm

Wicked wrote:Not sure how correct this is: but an old Navy instructor told me that a 5.56 M4 profile barrel increased + 7 deg. F with every round fired. Heavy barrels would heat up slower and also cool slower I would assume? Temperature of the barrel would really depend on the firing schedule. A 30 rd magazine fired continuously on a 90 deg. summer day would get the barrel to 300 deg. like right now. Dump just one more mag, and you're looking at 500 deg F.


Can anyone verify or correct this 7 deg. data?
I have never heard the 7 degrees for a barrel, I have heard 7 degree for every shot from a 5.56mm silencer.

I think it was Dater that was saying that, but maybe it was the barrel.

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rogerme
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Re: How hot does a barrel get?

Post by rogerme » Wed Aug 08, 2012 12:10 am

CharlieBravo wrote::lol: Did it leave a mark? I burnt my fingers, that was enough for me.
Not a permanent one but it did make one hell of a blister!
"If you carry a gun, people call you paranoid. That's ridiculous. If I have a gun, what in the hell do I have to be paranoid about?"

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Re: How hot does a barrel get?

Post by CharlieBravo » Wed Aug 08, 2012 12:32 am

Bendersquint wrote:There is a reason why the bushing is in brass.

Why does everyone always want to reinvent the wheel when it works great as it is?
Can you please expand on your statement? I too suspect there is a reason for making it out of brass, however that reason eludes me.

Man, you sure come acoss as grumpy sometimes :mrgreen:

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Re: How hot does a barrel get?

Post by Bendersquint » Wed Aug 08, 2012 1:02 am

CharlieBravo wrote:
Bendersquint wrote:There is a reason why the bushing is in brass.

Why does everyone always want to reinvent the wheel when it works great as it is?
Can you please expand on your statement? I too suspect there is a reason for making it out of brass, however that reason eludes me.

Man, you sure come acoss as grumpy sometimes :mrgreen:
Brass can expand, compress and contract better than SS would so as heat fluctuates it can still maintain a seal and perform its job better as the rear of the reflex.

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Re: How hot does a barrel get?

Post by CharlieBravo » Wed Aug 08, 2012 1:07 am

Thank you! You have teached me something again. It might be obvious to you but just so you know,I really appreciate that you're making an effort to share your knowledge.

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Re: How hot does a barrel get?

Post by Bendersquint » Wed Aug 08, 2012 1:56 am

CharlieBravo wrote:Thank you! You have teached me something again. It might be obvious to you but just so you know,I really appreciate that you're making an effort to share your knowledge.
You are welcome.

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Re: How hot does a barrel get?

Post by Historian » Wed Aug 08, 2012 8:02 am

Bendersquint wrote:
CharlieBravo wrote:
Bendersquint wrote:There is a reason why the bushing is in brass.

Why does everyone always want to reinvent the wheel when it works great as it is?
Can you please expand on your statement? I too suspect there is a reason for making it out of brass, however that reason eludes me.

Man, you sure come acoss as grumpy sometimes :mrgreen:
Brass can expand, compress and contract better than SS would so as heat fluctuates it can still maintain a seal and perform its job better as the rear of the reflex.
Kudos, Mr. B!. You solved the unanswered question I curiously posed in the 1960's to an armorer OCONUS
on why he used heavy brass discs as baffles in his one-off special use .45 ally cans. All I got was a slight
head turn smirk and " ... don't know, just a simple minded country boy's working around stills."

It is even funnier and more enjoyable lo these many years thanks to you.
Hope God is STILL SHINNING on his soul.


Best.

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