Project Break My Colt 6720 (pencil barrel).

[The Dumb Gun Collector]

Hey guys,

As some of you know I enjoy keeping notes on shooting my various guns. I started doing this over on HKPRO with my P2000 and then HK45. I have done a few more on J-frames, Wilson combats etc. I am not actively trying to destroy the guns, it is really just a collection of experiences and data points. One thing I have never done is really keep up with my rifles. I sold all my assault rifles a few years back to make some money during one of the various panics so my oldest current AR is this 6720. It is my training carbine and I basically treat it like garbage. I have another 6720, a DD LW, SCAR-17 that I baby, but I don't clean or do much for old Mildred.

Here are things I have changed.

Of course I added a T-2 as soon as I could. In fact, I found the T-2 for a good price and then I bought the rifle to have something to put it on. Then I bought one of the magpul SL forends because I originally planned to skip rails. I put a Arisaka Scout light on it, DD rear sight, vickers sling BCM stock and probably should have kept it here...
Untitled by stoiclawyer, on Flickr
Well, because I am an idiot I decided I needed a keymod rail. I picked up one of the DD rails and grinded down the front sight post like an idiot. What a bunch of hassle. I would totally go with adco to shave down the FSB next time. After I put the DD rail on I then stripped out the screws like a dumbass and had to wait for replacements. After that I bolted on a DD front and put an old X300 I had laying around. This is how it looked for most of its life...(at some point I swapped the T-2 onto my DD and put an H-1 I got on sale onto Mildred....

Untitled by stoiclawyer, on Flickr


Well, I got bored with it a month or two ago and spray painted it....

Untitled by stoiclawyer, on Flickr

And now I added a BCM forgriq, pistol grip and an aim point cover so I could just be a complete Larry Vicker's fanboy. I am just figuring out where to put it so I haven't put my keymod covers back on the bottom yet. I have resisted fore-grips for decades but here it is....


Untitled by stoiclawyer, on Flickr


At this point the carbine has 3352 rounds through it. This includes Various types of 55 grain XM193s, 855s, 77grain CBC, and a mother crap ton of steel cased TULA and Monarch ammo. For the last 800+ rounds I have stopped cleaning it because I am lazy. I still spray rem oil on the bolt and work it back and forth.

The gun functions perfectly and...wait for it...has never jammed. I am sure someone will call BS, but it just hasn't. I have a buddy who is into AKs and is constantly telling me about how reliable they are vs ARs and I keep asking him when he can recall on of my AR's jamming. At some point soon this one will because I have decided not to clean it until something stops working.

I wish I had recorded a series of groups with it when I first bought it but I didn't However, I have done a series of groups recently with


American eagle Xm193 3 groups of 5@ 100 yards (3.6 average)
CBC/Magtech 77 grain 3 groups of 5 @ 100 yards (1.42 inch average)

All groups shot off Caldwell shooting bag.

Before you scoff at my pitiful groups remember 1. I am not a ninja, 2. these groups were shot with a 2moa dot, 3. this has a mil-spec trigger, 4. I don't cherry pick or toss out fliers.

I will continue to shoot about 200 rounds a week of steel through it and try to monitor the groups with the steel stuff over the months.

[R0CKETMAN]

Solid set up. Hate the rail gets so much crap for Design / movement as of late. Suppose DD should go to RIS II attachment.

[rickgman]

Greg, Is there a reason that you stuck with the pencil barrel? Is that simply because you didn't wish to change out the barrel or do you prefer the pencil barrel?

[jstalford]

Greg, Is there a reason that you stuck with the pencil barrel? Is that simply because you didn't wish to change out the barrel or do you prefer the pencil barrel?

He must like it if he not only kept it but got a second as well.


Sent from my iPhone using Tapatalk

[The Dumb Gun Collector]

Rocket,

Yeah, I'm lucky I just locktited mine and used proper torque settings so mine hasn't moved. I do keep an eye on it though. My DD rifle has the same rail and it hasn't moved--but it gets very light handling as compared to the neglectful treatment this rifle gets.


I love pencil barrels! Nice and light! I am 43 so I really don't like too much extra weight.

[rickgman]

Greg, why do you feel that the slight reduction in weight is beneficial? When one adds lots of accessories to an M4, I personally don't notice much difference due to barrel weight. Given the potential issues with barrel harmonics and barrel flex when using a sling, I sort of favor a heavier barrel. Perhaps that's just me.

[friendlyfireisnt]

Greg, why do you feel that the slight reduction in weight is beneficial? When one adds lots of accessories to an M4, I personally don't notice much difference due to barrel weight. Given the potential issues with barrel harmonics and barrel flex when using a sling, I sort of favor a heavier barrel. Perhaps that's just me.

It's not such a slight difference, once you feel it. And once you add in a light and a VFG, it's still going to be lighter than a Gov't profile with the same accessories added.

And before someone says that lightweight barrels aren't accurate, there really isn't much of a penalty, as shown below.

DD American Eagle Varmint by Photographer Pilot, on Flickr

[Doc Safari]

The gun functions perfectly and...wait for it...has never jammed. I am sure someone will call BS, but it just hasn't. I have a buddy who is into AKs and is constantly telling me about how reliable they are vs ARs and I keep asking him when he can recall on of my AR's jamming. At some point soon this one will because I have decided not to clean it until something stops working.

My every day shooter BCM has had only one malfunction (when it was new) in nearly 6,000 rounds, so I believe you.

I keep it lubed regularly, but I've only cleaned it on rare occasions when I think it's gotten the desert sand in it.

So your experience is no surprise to me at all.

[rickgman]

It's not such a slight difference, once you feel it. And once you add in a light and a VFG, it's still going to be lighter than a Gov't profile with the same accessories added.

The weight difference is approx. 1/2 lb between the original M4 barrel and the later heavy barrel. I personally don't think that is all that significant in the overall scheme of things. Of course, that is just my opinion.

I don't deny the accuracy of a light barrel under ideal conditions. However, if you are employing a sling for stabilization, the heavier barrel resists barrel bending and that phenomenon has been well known since the early days of the M16 rifle. With a light weight barrel, our POI can change based on how much sling tension is on the rifle. That's one of the reasons that match rifle shooters who use AR platforms like free floating handguards.

[pyrotechnic]

The weight difference is approx. 1/2 lb between the original M4 barrel and the later heavy barrel. I personally don't think that is all that significant in the overall scheme of things. Of course, that is just my opinion.

I don't deny the accuracy of a light barrel under ideal conditions. However, if you are employing a sling for stabilization, the heavier barrel resists barrel bending and that phenomenon has been well known since the early days of the M16 rifle. With a light weight barrel, our POI can change based on how much sling tension is on the rifle. That's one of the reasons that match rifle shooters who use AR platforms like free floating handguards.

The 1/2 lb being out front makes a difference in how the gun handles, even if the overall weight change isn't that much. Also, the standard government profile puts extra thickness in front of the fsb where it doesn't do anything to benefit you.

With free float handguards sling tension is a non issue, unless your using irons and slung up so tight you're deforming the handguard.