My new build "Dimples"

AR/M4 Custom Build Forum
1

I reconfigured this gun to be a little less nose heavy, and better balanced overall. This gun started out as pictured below with the PRI rifle length carbon fiber handguard, LaRue low-profile gasblock, and the Vltor VST-1 attached to the barrel as a clamp-on folding front sight only (not as a functional gasblock). It ended up being too front heavy, and after running a few hundred rounds thru it, it just felt a little clunky when shooting multiple target drills.

Previous configuration:

I decided to try and balance it out, and wanted to have the barrel re-profiled a bit to lighten-up the front end. I saw that ADCO recently started doing barrel dimpling, and thought that might be perfect for this project. So I sold-off the handguard, and the Vltor VST-1 front sight to get the project started.

I swapped out the PRI tube for the VTAC/Troy 11" Extreme BattleRail, and I ordered one of KAC’s new rail mounted Micro-Flip folding front sights. As was previously mentioned, I sent my barrel to ADCO last Saturday to be dimpled and coated with KG GunKote (Flat Black), and got it back exactly one week later.

Here’s some pics of the finished product:




I havent had the chance to shoot it yet, but it just feels much, much lighter, and about as perfectly balanced as any rifle I have ever handled.

Here’s an updated list of the spec’s:

UPPER:

*Daniel Defense M4 upper receiver

*Daniel Defense M16 BCG

*BCM 16" 1/7 Hammer Forged Middy barrel/Dimpled by ADCO

*VTAC 11" Extreme BattleRail

*BCM GunFighter Charging Handle

*LaRue low-profile gasblock

*Surefire MB556K Muzzle brake

*KAC Micro-Flip folding front sight

*MagPul MBUS rear sight

*MagPul AFG

LOWER:

*Stripped S&W M&P15 lower

*Colt LPK

*LMT standard MilSpec Trigger group tuned by Bill Springfield (4.5lb break)

*STARK Equipment SE-1 Grip

*MagPul ACS stock

*MagPul B.A.D.

OPTIC:

*Trijicon TR24G (Green Triangle) 1-4x24

*LaRue LT-135 (1.93" height) SPR mount

*It will wear a Surefire X300 in the 12 o’clock position directly in-front of the KAC folding front sight.

2

Cool, I kinda like the look.

3

Nice job :smiley: Did they give you an estimate of how much weight you save dimpling the barrel?

4

That looks awesome. Have the dimples effected accuracy in any way? Any problems working with ADCO? I’ve Emailed them twice and tried to call. Their answering machine message says “Don’t bother leaving a message. The machine doesn’t get checked”. I haven’t been able to contact them. Maybe I’m doing something wrong. I got a unmarked Noveske middy basic that I’d like to do the same thing to. Any advise would be greatly appreciated.

5

I love it it just looks great! I hate your pistol grip though

6

Looks nice, I like your pistol grip, but I like the PRI tube better.:smiley:

7

I only had the barrel dimpled in-front of the gasblock.
Prior to dimpling the barrel weighed 1.76lb

After dimpling 1.62lb

Not a huge weight reduction, but I wasnt looking for an ultralight barrel on this one. Just a well balanced rifle.

8

Havent shot it yet.

ADCO has done work on 3 different barrels for me in the past. Never a problem, the work was always done exactly as I requested, and I always had my barrel back within 7-10days. I have never talked to anyone over the phone there. I just placed the order for the specific shop service I wanted, and included any specific instructions I also wanted in the comments section when placing my order.

Check the FAQ section in the shop services page for all of the info you need.

9

Thanks! Yeah, the STARK grip sure aint the best looking grip out there, but it’s the most comfortable by far for my hand. I also run one on my duty rifle.

I really liked the PRI tube also, but I found that I needed a continuous/uninterrupted top rail to facilitate proper eye relief with the Trijicon
TR24G/LT-135 and my preferred stock length of pull/shooting nose-to-charging handle.

And no matter how tightly I tightened down the handguard nut, the PRI tube still had a little bit of rotation by using just my hands. It took a bit of force to rotate it, but I just dont feel comfortable running a rail mounted filp-up front sight on the PRI tube.

10

Thanks for the reply and info.

11

That’s a great look.
How do you like the Troy BattleRail, does it fit “tighter” than the PRI? I ordered one about a month ago and waiting for it to finish a build.

12

what dis ADCO charge for the barrel? looking to have the same thing done. do you notice the change in weight?

13

The VTAC/Troy BattleRail attaches in a completely different manner than the PRI tube, but I can’t make the VTAC rotate at all by using my hands.

14

They charged me $115 to dimple in-front of the gasblock & re-parkerize the barrel. It is more to dimple under the handguard. Check the “Shop Services” page on ADCO’s website for more info.

15

I just put it on the scale with a Surefire X300 attached: 8.94lbs (No Magazine)

16

If by some miracle you were able to muster up silverback gorilla arm strength and move it, you’re either moving in a direction that would tighten the barrel nut (which would have to work against the gas tube), or running into the anti-rotation tab. As long as the two screws at the base of the rail are nice and snug, there isn’t any budging this rail. My ADM Micro mount bridges the gap by 1 slot for a little unintended insurance against rotation.

17

Nice. I’m so drooling over that barrel and rail combo. I want to try an ACS on mine to balance out the 13" rail a little better. With the CTR, the rifle felt a bit to nose heavy at the range today. I still marvel at how light this rail is for the length. My cousin brought his 20" Oly bull barreled rifle by with their incredibly heavy FF tube and he freaked out when he picked up my rifle to compare weight.

18

My LaRue LT-135/TR24G also bridges the gap on mine.

19

I think the Troy version “BattleRail” would have been a bit of polka-dot overload though:D

20

A little extra grater for your cheeses. Did you notice an improvement in your heat dissipation? I can’t tell if the improvement is the rail or my LW barrel. Probably a combo.