M4 To Lightweight? > AR Discussions

Posted: 4/19/2007 7:50:06 PM EDT

I've been waiting to hear from CMMG on when they might be making a 14.7 lightweight barrel but, I'm getting antsy waiting. Can someone tell me the diameter of the narrow part of an M4 barrel? Could a 14.7" M4 barrel be turned on a lathe down to lightweight dimensions? Here in Illinois it MUST be 16" total, no exceptions. I am planning on a retro build with a permanently attached A1 birdcage flash hider.

Doc

Posted: 4/19/2007 9:04:39 PM EDT

[#1]

Yes, Several places can do it. You might want to see if you can get a Bushmaster super light barrel. Very close to what you want. 1/9 and no M4 feedramps. But crome lined. And I have to give bushie one thing, They have some nice barrels. In the long run less expensive than haveing the barrel turned down and refinshed. It will approx. Double the cost. A striped Bushie 16in super lite should be less than $250. Keep your eyes out on the EE and you might get one for less.

Posted: 4/19/2007 9:23:21 PM EDT

[#2]

Quoted:
You might want to see if you can get a Bushmaster super light barrel. Very close to what you want.

+1

Anything you do to the M4 barrel (.610 BTW) will still leave you with a .750 gas block seat diameter. A 16" Bushmaster Superlight cut to 14.7" with an A1 attached would be a much better match for your clone.

Posted: 4/20/2007 4:54:25 AM EDT

[#3]

Thanks for the replies and the advice. I have been considering the cut down 16" but, I wanted to investigate all the options before I go and have someone modify a brand new barrel. Thanks again.

Doc

Posted: 4/20/2007 7:00:24 AM EDT

[#4]

One other point. Its a lot less expensive to cut down and rethread a 16in. Than to reprofile a 14.5. And refinsh it. Also most compatent gun smiths can do it. Point to keep in mind.

Posted: 4/20/2007 7:03:59 AM EDT

[#5]

AR15barrels.com could turn down a 14.7" M4 barrel to lightweight profile.

If you wanted it to look legit, you would also need to purchase a .625 front sight base to replace the .750 front sight base that comes with the M4 type barrel.

.625 FSBs are available from CMMG.

I would estimate that it would cost around $200 to purchase the .625 FSB and to have the M4 barrel reprofiled and refinished.

Posted: 4/20/2007 1:05:10 PM EDT

[#6]

You can still use a 14.5" barrel. You just need a spacer. I saw someone else on here do that same thing. I can't stand the look of a 16" M4 barrel. It just doesn't look right. So I boufght a 14.5" and had a spacer and A1 flash hider permanently attached. Here's a close up of my barrel and flash hider:

And here is a pic of the rifle altogether:

I think it looks very acceptable. It doesn't have that freakishly long look of a 16" barrel and it is legal. Just to give you another idea of what's possible...

Warning

Confirm Action

[ARCHIVED THREAD] - M4 To Lightweight?

[ARCHIVED THREAD] - M4 To Lightweight?