Barrel dimpling a thinner contoured barrel

[TACAV]

I looked around in past threads about this but didnt get an answer, in fact someone else asked a similar question in the one large thread on barrel dimpling and he didnt get an answer either.

In regards to dimpling a barrel, (as in Marvin Pitts or ADCO dimpling)

how does that work with the already lighter contoured barrels? I was thinking of sending a 16" BHF BCM Middy to Marvin. The way the barrel is shaped it is thicker from the barrel end to the gas block but thinner from the gas block to the receiver. It is not a lightweight profile.

This one here.

http://www.bravocompanyusa.com/BCM-BFH-16-Mid-Length-Upper-Receiver-Group-p/bcm-urg-mid-16%20bfh.htm

Should I stick with just having the front end dimpled and leave the rear half as it is? Would there be any noticeable con of having the entire thing dimpled?

btw, I am having this done for pretty much aesthetic reasons. It will go under a Noveske NSR rail on a fun/entertainment build (nothing for work etc) I dont expect any major accuracy changes (or should I)

Thanks,

[Kokopelli]

I wouldn't think there would be enough material do much behind the gas block.. JMO.. Ron

[TACAV]

I wouldn't think there would be enough material do much behind the gas block.. JMO.. Ron

Yea that was what I was thinking, but I was also wondering the dimpling process would just compensate but being more shallow in that area and thus removing less material.

[davemcdonald]

I would go with in front of the gas port dimple. I doubt there is enough material on the thin part of the bbl. Marvin does great work. I have a 12.5 Noveske dimpled and the weight shift is very noticable. Accuracy has not been affected. He also pinned Surefire 212a flashhiders on some 14.5 Novesk uppers that I worked up for my twin daughters. He is highly recomended!

[TACAV]

Cool thanks guys!

[TACAV]

Marvin got back to me today. Apparently it is entirely possible and it still works too.

He sent me this pic of a KAC SR-15 Light Contour Barrel with his dimpling on it.

http://i105.photobucket.com/albums/m217/map32968/Todd/DSC05155.jpg

[Warg]

Having only the front dimpled on that profile has a negligible effect on removing mass and cooling if that's what you're seeking. It is really for looks more than anything else.

Doing the entire barrel, however, will certainly help.

I've had lightweight profile (i.e., pencil profiles that are thinner than the KAC profile pictured above) barrels dimpled as well. They look great, but have seen repeatable changes in POI due to overheating. I would not recommend this service for these profiles except, perhaps, for hunting where you're not shooting a lot of successive strings.

[TACAV]

Having only the front dimpled on that profile has a negligible effect on removing mass and cooling if that's what you're seeking. It is really for looks more than anything else.

Doing the entire barrel, however, will certainly help.

I've had lightweight profile (i.e., pencil profiles that are thinner than the KAC profile pictured above) barrels dimpled as well. They look great, but have seen repeatable changes in POI due to overheating. I would not recommend this service for these profiles except, perhaps, for hunting where you're not shooting a lot of successive strings.


Yea its just for looks. This gun is not for work purposes or anything like that.

The upper I am sending him is a standard BCM middy.
Just out of curiosity have you ever measured to see just what type of POI shift you did get after getting the barrel nice and hot?

Dumb question,
Anyone know if the thinnest tapered profiled area of the barrel (between the gas block and receiver) on a standard BCM middy is the same as a standard true lightweight barrel?

[Warg]

.
Just out of curiosity have you ever measured to see just what type of POI shift you did get after getting the barrel nice and hot?



As much as an inch on an 18" barrel at 100 yards. This was not consistent in the spread or the direction IIRC and depended on the ammo.

I didn't experience that degree of POI delta with a shorter barrel, but I typically shoot these uppers for precision with lots of time between shots.

[Brahmzy]

I've had Marvin hook up 4 Noveske barrels and soon a 5th for me. All medium contours. I did mine to drop weight, not so much for looks. I would not get a lightweight barrel done on a working gun. I might pick up an NST 16, and As much as I'd love the super light weight of that barrel plus dimpling, the deflection with changing temps would be too great IMO - especially the longer the barrel is. You could dimple a LW 10.5 and probably never see a difference.

[Neo Mara]

Marvin got back to me today. Apparently it is entirely possible and it still works too.

He sent me this pic of a KAC SR-15 Light Contour Barrel with his dimpling on it.

http://i105.photobucket.com/albums/m217/map32968/Todd/DSC05155.jpg

I wonder if thats my SR-15 barrel :D I've never sent work to to ADCO so I can't comment there but Marvin was perfect and did everything exactly as I requested on two different barrels. I plan to send more work his way in the future.