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JConn
12-11-2012, 07:46 PM
This seems like something that doesn't make much difference. I'm trying to finish an ar15 and want a 14.5" carbine length gas system barrel. Bravo co only has the regular profile in stock and I had my eyes on the lightweight profile. Should I just buy what's in stock or hold out for the lightweight barrel? I don't know what the weight savings are but they seem like they would be negligible.

SLG
12-11-2012, 07:58 PM
I don't know how much of a difference it is, but http://www.centurionarms.net/index.php?option=com_virtuemart&Itemid=136 has a lightweight barrel profile that I have found to be a legit 1moa setup. Tough to beat their quality and customer service, especially since Monty is still active duty.

JConn
12-11-2012, 08:57 PM
I don't know how much of a difference it is, but http://www.centurionarms.net/index.php?option=com_virtuemart&Itemid=136 has a lightweight barrel profile that I have found to be a legit 1moa setup. Tough to beat their quality and customer service, especially since Monty is still active duty.

Very cool, I was kind of hoping to just buy an upper already assembled but I suppose I could go get a torque wrench and an upper and call it a day. I worry about assembling things like this myself though.

JV_
12-11-2012, 08:58 PM
I could go get a torque wrench

If you want to head out this way, you can use mine.

SLG
12-11-2012, 09:28 PM
Very cool, I was kind of hoping to just buy an upper already assembled but I suppose I could go get a torque wrench and an upper and call it a day. I worry about assembling things like this myself though.

You can get a complete upper from Monty as well. I thought you were only looking for a barrel, for some reason.

JConn
12-11-2012, 09:45 PM
You can get a complete upper from Monty as well. I thought you were only looking for a barrel, for some reason.

Do you know if he would do just upper and barrel? I already have handgurds bcg charging handle etc.

SLG
12-11-2012, 11:53 PM
Do you know if he would do just upper and barrel? I already have handgurds bcg charging handle etc.

No problem. Just tell him what you want done, send him the parts that you have, and he'll put it all together.

I sent him a flashhider and a handguard, and he built the rest around them.

DocGKR
12-12-2012, 12:00 AM
Centurian makes fantastic gear; highly recommended!

Odin Bravo One
12-12-2012, 12:26 AM
Triple L is one of the good guys.

His guns and gear are top shelf. One of the best builders that nobody knows about.

Kyle Reese
12-12-2012, 03:09 AM
Centurian makes fantastic gear; highly recommended!

Agreed. Monty built my MK 12 Mod 1 upper a few years back and it's a magnificent shooter.

JHC
12-12-2012, 09:16 AM
This seems like something that doesn't make much difference. I'm trying to finish an ar15 and want a 14.5" carbine length gas system barrel. Bravo co only has the regular profile in stock and I had my eyes on the lightweight profile. Should I just buy what's in stock or hold out for the lightweight barrel? I don't know what the weight savings are but they seem like they would be negligible.

I'm not a big guy and I find my BCM lightweight middie to be far easier to use all day in training or even for offhand shooting (50 and 100 yds at my club). It really is noticeably (to me) lighter than the N4 Recce's barrel which is more like an M4 contour. Wait for or find from Centurian what you want is my $0.02

JRas
12-14-2012, 12:44 PM
you should go to the other spectrum and get a SOCOM barrel, less barrel whip = better accuracy

wilco423
12-14-2012, 06:46 PM
I currently run a DD 10.3"LW as my duty gun. It has been through an EAG carbine 1 and TRICON carbine 2, and has done very well in the combat accuracy department. Tack driver? No, but it regularly shoots 2-3 MOA with XM193 (when I do my part, of course), which is plenty good for me.

Weight savings on a 14.5" should be 4oz or so. Doesn't sound like a lot, but as others have said, due to where the weight is, the lighter barrels handle very nicely. If you're considering a can in the future, I'd stick with the standard barrel. JM2C.

TGS
12-14-2012, 07:15 PM
1) Would a CHF barrel decrease POI shift from heating or barrel whip with a pencil barrel as opposed to a non-CHF thin profile barrel?

2) Do you guys find the thin barrels to open up as heat builds up throughout the shooting session? i.e. your 2-3 MOA DD becomes a 4-6 MOA DD when warm.

This is certainly a factor people mention with just about any gun that doesn't have a heavy barrel, I'm wondering why people don't mention it with their AR15 carbine.

joshs
12-14-2012, 07:28 PM
1) Would a CHF barrel decrease POI shift from heating or barrel whip with a pencil barrel as opposed to a non-CHF thin profile barrel?

2) Do you guys find the thin barrels to open up as heat builds up throughout the shooting session? i.e. your 2-3 MOA DD becomes a 4-6 MOA DD when warm.

This is certainly a factor people mention with just about any gun that doesn't have a heavy barrel, I'm wondering why people don't mention it with their AR15 carbine.

The profile under the hand guards is identical or very similar between most LW and Gov't profile barrels. I don't understand how having the barrel heavier from the gas block forward is going to help with heat/POI shift that much.

TGS
12-14-2012, 07:57 PM
The profile under the hand guards is identical or very similar between most LW and Gov't profile barrels. I don't understand how having the barrel heavier from the gas block forward is going to help with heat/POI shift that much.

I was under the impression that not all LW barrels are the same under the hand guards, that some are thinner: https://spreadsheets.google.com/pub?key=tiAxcuxDRXuahtGz5Q1DJRg&output=html

Explain this to me if I appear confused :o

joshs
12-14-2012, 08:10 PM
I was under the impression that not all LW barrels are the same under the hand guards, that some are thinner: https://spreadsheets.google.com/pub?key=tiAxcuxDRXuahtGz5Q1DJRg&output=html

Explain this to me if I appear confused :o

The Noveske in the link is actually thicker than Gov't profile under the hand guards. The linked Centurion is a thicker profile at and forward of the gas block compared to light weight barrels using the .625 GB.

Odin Bravo One
12-15-2012, 12:09 AM
Another option is to call Monty and/or John, tell them what the requirements/desires are, discuss options, and get expert opinions from the experts themselves. A 10 minute conversation with either of them will enlighten and educate immensely. I won't bother to try to regurgitate the information supplied to me by both of them over the years as I will fumble around and f&*@ it up. Both have forgotten more about AR barrels than most mortal men will ever know.

wilco423
12-15-2012, 01:01 AM
I've never tested mine on mechanical accuracy cold vs hot, but I think it opens up a little, and the POI changes a little as well. I don't perceive it to be significant. I only really worry about cold, as I know that's likely the only way it will ever be used. I'll try to check it next time I'm out, but as Sean suggested, going to the pros is the best answer.

YVK
12-15-2012, 11:26 AM
2) Do you guys find the thin barrels to open up as heat builds up throughout the shooting session? i.e. your 2-3 MOA DD becomes a 4-6 MOA

Over a year ago, partly because I was impressed how accurate my SCAR-L was, I had a BCM barrel turned down to 0.580 or something like it. Group diameter started to double after one magazine of a slow-to-moderate fire.

lindertw
12-15-2012, 05:02 PM
not sure if photos will help out at all (I don't have weights):

http://i910.photobucket.com/albums/ac306/lindertw/barrel_compare.jpg

http://i910.photobucket.com/albums/ac306/lindertw/barrel_profile_compare2.jpg

*eta: I have some temp data from a 600 round test I did a few years back (I was curious how hot things got), but I didn't really measure change in group size during the test. If you're interested I can post here.

rob_s
12-20-2012, 05:09 AM
some data (https://docs.google.com/spreadsheet/ccc?key=0Ajl2UPK0UHPsdGlBeGN1eERSWHVhaHRHejVRMURKU mc)

In general, when it comes to a first rifle, I tell people to buy what they can get rather than wait for what they think they want. I'd rather have a 16" A2 profile barrel in hand than a 14.5" A1 profile still waiting to be made. But once that first (and preferably second identical, or nearly identical) rifle is in hand, wait for what you want. You want it, or think you want it, for a reason and once you have guns you can shoot if you compromise you'll just wind up buying the other one later on to satisfy that nagging voice in the back of your mind.

Jay Cunningham
06-18-2013, 12:47 PM
I started a thread specifically on the Colt 6720:

http://pistol-forum.com/showthread.php?8593-Thoughts-on-the-Colt-AR6720-Lightweight-LE-Carbine&p=141070#post141070