Dimple on a QPQ Nitride Barrel

[ben0341]

Hey everyone,

I know this subject has been beaten to death and I have done a ton of reading on this but it seems to be a 50/50 split on if you should dimple or not. I just wanted to get some recent thoughts on what everyones opinon is since most of the threads on this are pretty old.

I am building my second AR and I have a Faxon 10.5 barrel that is nitride(QPQ)coated. I have read it can be a pain to drill through but is probaby doable with a colbalt bit and some time. Anyways are the dimples main purpose just to locate/index the gas block? With the two gas blocks I've used they have a much bigger port than the barrel and by making pencil marks it seems pretty easy to get it perfectly aligned. I also flipped the GB upside down and could tell it was indexed all the way up against the barrel shoulder without the tiny gap that some builders have.

My first build I did not dimple the barrel and used red loc tight and it hasnt moved on me. Ive put about 600 rounds through it so far. I know I am probably over thinking this but I want to make sure I dont run into the possibility of it moving if I ever need to use it in a serious situation.

Any advice is appreciated.

** Gas block is a Seekins Adjustable, and it will be under a FF handguard.

Thanks!

[MorphCross]

Definitely dimple the barrel. The dimple along with loctite and the knurled cup face set screws are used to keep a steel gas block from vibrating loose under high temperatures.

[drtywk]

Dimple it. I have a dimple jig and drill bits if you need to borrow one, just cover shipping.

[tostado22]

Your GB placement does more than line up the gas port on the barrel with the port of the gas block. If it is set out of alignment, or works it's way off over time, that affects your gas tube alignment as well. I see no reason NOT to dimple and I wish more companies would.

[ben0341]

Thanks alot for the quick replies guys. Looks like I am going to dimple both of my barrels. I hate doing anything halfway and it seems like its the only surefire way to make sure its not going to walk on me.

[ben0341]

Dimple it. I have a dimple jig and drill bits if you need to borrow one, just cover shipping.

Wow thats great of you to offer that! I really appreciate it but I do plan on building 2-3 more so I might as well order one. Any suggestions on which jig to look for or will any of them work ok? Also for my barrel thats Nitride does a cobalt drill bit do the trick? I've read mixed reviews on that one.

[ben0341]

Your GB placement does more than line up the gas port on the barrel with the port of the gas block. If it is set out of alignment, or works it's way off over time, that affects your gas tube alignment as well. I see no reason NOT to dimple and I wish more companies would.

Yeah especially since the dimple under the gas port is universal. Kind of bummed I didn't know about this before hand or I would have went with a barrel manufacture that pre dimples. At least I know now for future builds.

[Todd.K]

I know this subject has been beaten to death and I have done a ton of reading on this but it seems to be a 50/50 split on if you should dimple or not.

I hope that number comes from TOS. Many will never use an AR hard enough or for enough rounds to have a problem with a gas block shifting. It DOES happen and I've seen it. If you are not going to do it right and pin the gas block to the barrel, dimpled is about 100 percent better than not.

[Blackhalo]

I always do one dimple, and after trying everything known to man(map gas,un-cure etc) to remove a BCM installed gas block I trust it as much as pinning. I finally got it but it took some effort.

[markm]

I was on the fence until we had a gas block slip. I think it was on that piece of shit Faxon barrel. I'll dimple every barrel from now on if it doesn't already have that feature in place.