View Full Version : barrel thickness
I searched and couldn't find a direct answer to this. If I missed it I apologize
What are the real differences in performance between a lighter barrel
Like a scar16 or ddm4 lightweight and the standard
M4 or government profile barrels. I know Larry vickers uses a
Lightweight on his signature carbine, but most other well known
Instructors appear to use the heavier barrels as does the .mil crowd.
The military uses the M4 profile for mounting the M203. The M4 profile is also military standard, something that is very hard to change.
Lightweight profiles are ideal for patrol situations and are just the preference of some people. You just have to decide if the reduced weight is a real benefit for you
Performance is relative to requirements. More mass takes longer to heat up and is slower to cool, for lightweight the opposite. Temperature affects POI, lifespan among other things. Barrels also flex to some degree, thicker is stiffer. Lightweight weighs less -.- There are times when not having a boat anchor is advantageous.
I went through all the lightweight barrel options, even looking at Noveske's NST line of barrels on my last carbine.
In the end, I wouldn't give up accuracy/durability for weight. You can save a few ounces a number of ways.
If you want a rifle for taking classes with, I would consider one with a lightweight profile. There aren't too many which stretch beyond 50 yards, the accuracy difference isn't there.
Ammo selection is just important as barrel when it comes to accuracy too. If you aren't willing to reload or buy 75-77gr match ammo...you may never notice a difference.
In a conversation with DD about the S2W barrel profile they now offer, the rep said they are shooting about 1.5 MOA, out of a chrome lined barrel. 2-2.5 MOA out of the lightweight.
If you are considering getting a suppressor, i've read that lightweight barrels have a greater POI change when going between supressed/unsuppressed. I won't get to test this until my C&R license comes back. ;)
[QUOTE=If you are considering getting a suppressor, i've read that lightweight barrels have a greater POI change when going between supressed/unsuppressed. I won't get to test this until my C&R license comes back. ;)[/QUOTE]
How will a C & R License help you test this?
How will a C & R License help you test this?
Probably with a WWII C&R suppressor. Just a guess...
Not many WWII supressors running around.
Missouri state law requires you to have an FFL to own a SBR or supressor. A C&R license (FFL Type 03) satisifies this requirement. Nothing to do with a modern supressor, but works none the less.
Didn't Molon do some accuracy testing of different barrel profiles against one another? I can't find it now but if he hasn't he should.
If you're going to be using an RDS, and shooting XM193, agonizing over the potential accuracy loss in going from a GI-profile barrel to a lighter weight is silly.
and, to make sure that the point is not lost...
Everything that can be done to a gun with a heavier barrel to reduce weight can also be done to a gun with a lightweight barrel to get it even lighter. Preferring lighter weight with the same functionality is not a function of strength but of intelligent gear choice. Choosing a heavier tool when the lighter tool will do is not rational. No matter if you're peewee Herman or Charles Atlas, everyone is governed by the fomula:
you can carry X pounds for Y amount of time. As X increases Y decreases, and as X decreases Y increases.
PeeWee's X and Y may be lower than Atlas', but they are both governed by the same formula.
Personally, if I need a finer degree of accuracy I'm not choosing a "milspec" style barrel anyway. I'd go with a stainless steel barrel from Noveske or BCM. But if choosing the Noveske I'd still go with their lighter profile. :D
The thicker the barrel.... the SWEETER the juice!!! :D
MacDonalds straws aren't barrels.
Mr. Goodtimes
03-11-11, 08:38
I think to a degree it depends on how light the profile. Doesn't the SR-15 have a LW profile barrel?
I think to a degree it depends on how light the profile. Doesn't the SR-15 have a LW profile barrel?
I've not mic'd one, but to my eye, next to my DD LW, the SR-15 is a little thicker, so I'd call it a mid-profile.
In regards to the OP's question: I think people get way too wrapped around the axle about accuracy in a fighting rifle; I know, I used to be one of them. Here's what happens, we start to look at purchasing components or complete rifles, and we want the best. Buy once, cry once, right? Anyway, we dig into the specs and before you know it, we've got the mostest awesomest baddest assest rifle ever. Then, we put a sight on it that limits our potential accuracy purely based opon repeatable sight picture to 2MOA @ the least (usually 4 MOA). Then, unless all your shooting happens off the bench (and if this is the case, build a freakin' bench gun, not a RDS'd AR) you pick the gun up and shoot it, often while moving, seeking cover/concealment, different positions, etc...and we haven't even talked about what ammo you're running.
Now, I'm not saying to throw accuracy out the window, but it certainly should not rank #1 in terms of requirements for a fighting-type carbine. If your requirements are for continuous full-auto fire, buy a freakin' belt fed. Otherwise, a lightweight barreled AR will do everything you need it to and much more comfortably than other barrel profiles. FWIW, once I established my zero at my recent Vickers class I put roughly 400 rnds through my LW DD barrel and every target on every drill was clean. This was 4-10 shot groups per drill @ ranges from 7 to 25yds, off-hand, moving, against a timer, iron sights only. The black zone was 8". Is that super-precision? No. Did other people with magnified optics and heavier-profiled barrels drop more shots than I did? You bet.
To clarify, this is not to brag about my shooting ability, because an 8" group isn't really much to brag about, but rather to make the point that the benefits of the LW barrel far outweigh any drawbacks (and I don't really see any based on my needs/use of a carbine.)
Didn't Molon do some accuracy testing of different barrel profiles against one another? I can't find it now but if he hasn't he should.
Shooting 30 round groups, the lightweight barrel was larger than both the goverment and HBAR.
I also think its worth saying the Noveske NST barrels are lightweight for a SS barrel. They are the same weight as a goverment profile barrel.
https://www.m4carbine.net/showthread.php?t=72761
The pic below shows the results of firing three 10-shot groups in a row from each of the displayed barrels in a semi-automatic AR-15, from a bench-rest at 100 yards using match-grade hand-loads.
Colt 16” light-weight (pencil) profile, 6520 – 1 pound, 6 ounces
http://www.box.net/shared/static/x7ykufvv3j.jpg
Colt 16” M4 (government profile), 6920 – 1 pound, 12 ounces.
http://www.box.net/shared/static/qhjpk4qlr3.jpg
Colt 16” HBAR, 6721 – 2 pounds, 3 ounces.
http://www.box.net/shared/static/3bnl8bdr23.jpg
http://www.box.net/shared/static/in8cal2pcg.jpg
….
Before you buy a "fighting rifle" really evaulate if you're going to be fighting with it, humping it in a class, carrying it long distances etc etc. If you want to shoot one ragged hole at 100 yards, then buy accordingly.
NOT POSSIBLE!!! That 6721 is 1/9!!! :eek:
Sorry... I just had to. :p
<snip>
If your requirements are for continuous full-auto fire, buy a freakin' belt fed. Otherwise, a lightweight barreled AR will do everything you need it to and much more comfortably than other barrel profiles.
<snip>
Suitability to adapt to different roles without adopting entirely different equipment (and their supply chains) is advantageous in itself.
Saying it will do everything you 'need' it to is a bit general. Lightweight has a place, as does an HBAR/Gov't/Taper. Everything is a compromise, whether or not it's a compromise that's advantageous depends entirely on circumstance, application, and the person.
Powered by vBulletin® Version 4.2.5 Copyright © 2024 vBulletin Solutions, Inc. All rights reserved.