Bayonet Adapter on 16" M4 Barrel

AR-15 » Rifles, Uppers, Lowers, Barrels, and more

AR Sponsor:

[ARCHIVED THREAD] - Bayonet Adapter on 16" M4 Barrel

Posted: 9/11/2004 10:07:42 PM EDT

I'd like to attach this bayo lug to the 16" barrel shown below.
Where will the clamp need to be placed (on the main part of barrel or in the M203 cut-out)?
I need to know because the bayo lug comes in two different diameters (0.75 & 0.57).
I assume the below barrel is 0.75" in front of the front site, and 0.57 where the 203 cut-out is?

Posted: 9/11/2004 10:36:08 PM EDT

[#1]

Tagged!

I dont know anything about it, but it sounds pretty cool.

Posted: 9/12/2004 12:38:06 AM EDT

[#2]

BTW, I'm sure a company could turn some nice coinage by making a small 2 (or 3) sided rail (about 4-6" long), which clamps onto the base of the front sight and includes a bayonet lug on the bottom, in the correct possition for use with a 16" barrel.

EDIT:
Add a bayo lug to the front of this & it would be perfect!

YHM Triple Mount (YHM-639K)
This mount attaches to the barrel of your AR type firearm. It is designed to accept picatinny style attachments. Its three mounting surfaces allow you to attach accessories such as flashlights, laser sights, grips, etc. Clearance is provided for a bayonet lug. Mounts to barrels with diameters of .730 and .750 (required bushings included) with supplied cap screws. Made from aircraft quality aluminum and hardcoated to mil. specs.

Posted: 9/12/2004 11:15:57 AM EDT

[#3]

I read somewhere to use Teflon tape around the adapter so it won't mar your barrel. I guess the teflon tape can take the heat from the barrel. Does any one know if this is true. I am doing the same thing.

Posted: 9/12/2004 2:06:20 PM EDT

[#4]

Yeah, I was thinking along the same lines, although I hadn't quite figured out what to use. Teflon would be great if it can take the heat since its so thin.

What barrel profile do you have? And do you know where I can find the dimensions for my M4?

Posted: 9/12/2004 2:22:01 PM EDT

[#5]

Ok, I did a little work with photoshop with two pre-ban M4 uppers, placing them side by side, lined up by the tip of the barrels, and the bayo lug on the 14.5" barrel lines up where the adapter needs to be on the 16" M4 barrel.

My conclusion from what I saw was, mounting this adapter on the thicker part of the barrel in front of the front sight post and right before the 203 notch, will put the lug in the exact same position (in reference to the end of the barrel & the A2 birdcage) as it is on the real 14.5" M4 profile barrels (which supostedly is the correct combination for using a M7/M8/M9 bayonet).

I guess all thats left to figure out is the barrel diameter on the M4 barrels where it meets the front sight post. Any ideas? (0.75 or 0.57)? I'm guessing it's probably 0.75.

Posted: 9/12/2004 2:27:35 PM EDT

[#6]

Use a Dremel to open up the Dia' needed to mounting the lug bracket.

TG

Posted: 9/12/2004 2:31:44 PM EDT

[#7]

Found this in another thread:

Bushmaster 14.5" M4 Barrel - .640" under the handguards
.750" directly under the FSB
.720" immediately in front of the FSB
.745" forward of the barrel cut for the M203

So I'm guessing with a layer or two of thermal tape (teflon maybe), that'd bring it right up around 0.75 for the bayo lug adapter.

Posted: 9/12/2004 2:49:07 PM EDT

[#8]

Quick search on google found that most of the teflon PTFE tapes had a melting point between 450-600F. Most of the MSDS sheets I pulled up had 550F listed on almost all the tape brands.

So how hot can a AR15 barrel get?

Posted: 9/12/2004 2:57:44 PM EDT

[#9]

Quoted:
Quick search on google found that most of the teflon PTFE tapes had a melting point between 450-600F. Most of the MSDS sheets I pulled up had 550F listed on almost all the tape brands.

So how hot can a AR15 barrel get?

I think extended rapid fire would exceed those temperatures.

Posted: 9/12/2004 3:09:56 PM EDT

[#10]

Quoted:
Quoted:
Quick search on google found that most of the teflon PTFE tapes had a melting point between 450-600F. Most of the MSDS sheets I pulled up had 550F listed on almost all the tape brands.

So how hot can a AR15 barrel get?

I think extended rapid fire would exceed those temperatures.

I agree after witnessing the 3-gun match at the Va. BRD yesterday. Talk about a smoking gun.

Danny

Posted: 9/12/2004 3:13:02 PM EDT

[#11]

Any ideas on a material we could use?

Posted: 9/12/2004 3:24:04 PM EDT

[#12]

Quoted:
Any ideas on a material we could use?

Joking "asbestos"?

Danny

Posted: 9/12/2004 7:46:10 PM EDT

[#13]

Just ordered one from DMPS Arms. They've got it for $19.95 with free shipping!
www.dpmsinc.com/10Expand.asp?ProductCode=BL-LUG-H

Posted: 9/13/2004 11:07:18 AM EDT

[#14]

Anybody have a pic of one of these mounted on a barrel? I've got a double whammy (16" and DD 9.5FSP) and I want to put a bayonet on my rifle. It has the lug already, but is completely useless due to the afore mentioned issues. My AR is a '93 vintage already, since the term "pre ban" has absolutely no meaning anymore....

Posted: 9/13/2004 3:03:43 PM EDT

[#15]

There's a bayonet out there made for 16 inch barreled M4s. Saw the link in the main AR forum.

Posted: 9/13/2004 3:34:09 PM EDT

[#16]

Just went to the hardware store. I found Aluminum foil tape. It says it helps prevent heat loss and is rated for flame spread. How would this type tape be as compared to the teflon type for our use?

Posted: 9/13/2004 5:39:15 PM EDT

[#17]

Quoted:
There's a bayonet out there made for 16 inch barreled M4s. Saw the link in the main AR forum.

Yeah, I saw that too, but it looked dumb, it was a M7 with a 1 1/2" plug at the end. I'm looking to put a M9, high-speed, low drag bayo on mine

Posted: 10/4/2004 4:51:32 PM EDT

[#18]

Quoted:
Anybody have a pic of one of these mounted on a barrel? 8D]

Here ya go:

http://pic2.picturetrail.com/VOL30/138216/326854/68693110.jpg

http://pic2.picturetrail.com/VOL30/138216/326854/68693094.jpg

DW

[ARCHIVED THREAD] - Bayonet Adapter on 16" M4 Barrel

AR-15 » Rifles, Uppers, Lowers, Barrels, and more

AR Sponsor:

Win a FREE Membership!

Sign up for the ARFCOM weekly newsletter and be entered to win a free ARFCOM membership. One new winner* is announced every week!

You will receive an email every Friday morning featuring the latest chatter from the hottest topics, breaking news surrounding legislation, as well as exclusive deals only available to ARFCOM email subscribers.

Warning

Confirm Action

About AR15.COM

Stay Connected

Newsletter

Contact Us