View Full Version : Dimple on a QPQ Nitride Barrel
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
12-07-18, 22:15
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.
Dimple it. I have a dimple jig and drill bits if you need to borrow one, just cover shipping.
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.
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.
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.
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.
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.
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.
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.
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.
Are you saying that the Faxon barrel wasn't even dimpled???
My Faxon Big Gunner Nitride barrel wasn't dimpled. I had no problem at all doing it myself.
bamashooter
12-08-18, 12:23
I dimpled one of those Faxon barrels using whatever normal, good quality bits are made from. No problems but it was a little tough. My only barrel dimpling. I've installed 3-4 other gas blocks that either had 2 or 3 set screws. No dimpling, no issues.
Are you saying that the Faxon barrel wasn't even dimpled???
My Faxon Govt /Socom barrel wasn’t dimpled either. Here is what they say on their website about why they don’t dimple. I feel like it’s so easy for peace of mind they should be doing that for the price I paid.
Frequently Asked Questions: Does Faxon Dimple Their Barrels?
Aug 26th 2016
In a short-answer, no.
Why?
We believe it valuable for customers understand our reasons:
Adding the dimple would break through the corrosion resistant nitride layer on the barrel since we drill our gas ports after nitriding. Since most customers do not use a dimple, adding an unprotected path for corrosion is not advisable.
The dimple pattern is not standard across the industry. What works for one company or pattern will not work with many others.
A dimple is easy to complete at home for those looking to add it. If we added it in production for all barrels, it would add a full operation for itself, increasing lead times, cost, and price to the customer.
But What About Your Gas Block? It Uses Set Screws?
It does, but the dimple is not needed.
We use three set screws instead of the common two.
Faxon uses "flush cup" screws. The cupped screws each "bite" into the steel and when combined with the recommended thread-locking compound (either red Loc-Tite or RockSett), the gas block is locked into place.
Are you saying that the Faxon barrel wasn't even dimpled???
Nope. I dimpled it after the GB slipped.
I decided to be impatient and try a dimple without a jig. Wasn’t hard at all. I used an auto center punch in the middle of the impression left on the barrel. I have a jig en route for future builds but figured I would try it anyways. I was very surprised how easy a colbalt bit went through the nitride . Took me no more than 5-10 mins.
My Faxon Govt /Socom barrel wasn’t dimpled either. Here is what they say on their website about why they don’t dimple. I feel like it’s so easy for peace of mind they should be doing that for the price I paid.
Frequently Asked Questions: Does Faxon Dimple Their Barrels?
Aug 26th 2016
In a short-answer, no.
Why?
We believe it valuable for customers understand our reasons:
Adding the dimple would break through the corrosion resistant nitride layer on the barrel since we drill our gas ports after nitriding. Since most customers do not use a dimple, adding an unprotected path for corrosion is not advisable.
The dimple pattern is not standard across the industry. What works for one company or pattern will not work with many others.
A dimple is easy to complete at home for those looking to add it. If we added it in production for all barrels, it would add a full operation for itself, increasing lead times, cost, and price to the customer.
But What About Your Gas Block? It Uses Set Screws?
It does, but the dimple is not needed.
We use three set screws instead of the common two.
Faxon uses "flush cup" screws. The cupped screws each "bite" into the steel and when combined with the recommended thread-locking compound (either red Loc-Tite or RockSett), the gas block is locked into place.
Also from their FAQ:
Warranty Notification:
Faxon Firearms does not recommend dimpling until the system is fully checked.
If you feel the need to dimple the barrel, we suggest prior to dimpling, installing the gas block with the set screws and test the system. Once proper function is confirmed, you may dimple the barrel.
NOTE: Your warranty may be voided if dimpling is not performed by a gunsmith.
Nope. I dimpled it after the GB slipped.
I decided to be impatient and try a dimple without a jig. Wasn’t hard at all. I used an auto center punch in the middle of the impression left on the barrel. I have a jig en route for future builds but figured I would try it anyways. I was very surprised how easy a colbalt bit went through the nitride . Took me no more than 5-10 mins.
This may speak to the issue @markm had with their Faxon barrel giving the appearance of being shot "thousands of rounds" after only a few hundred were put through it. Maybe the supposed nitriding isn't actually hardening the surface layer of the steel and that's why the barrel wore so quickly? Either way, I'm almost completely sure I'll never buy another Faxon product, and forever warn others to stay away!
Also from their FAQ:
Warranty Notification:
Faxon Firearms does not recommend dimpling until the system is fully checked.
If you feel the need to dimple the barrel, we suggest prior to dimpling, installing the gas block with the set screws and test the system. Once proper function is confirmed, you may dimple the barrel.
NOTE: Your warranty may be voided if dimpling is not performed by a gunsmith.
Very true I should have added that in my post.
I’m not worried about a voided warranty on a $109 barrel. I’m pretty confident it will work. Drilling a dimple is pretty straight forward. The gas port hole in the gas block is a lot bigger than the port hole in the barrel so even if someone had it slightly mis aligned I don’t think it would affect anything. I spent a bit of time making all the marks and flipping it upside down to assure it should be seated against the shoulder without a gap. I hate when I overthink things sometimes. Just have to throw on my linear comp and I’m heading out back to give it a test run.
This may speak to the issue @markm had with their Faxon barrel giving the appearance of being shot "thousands of rounds" after only a few hundred were put through it. Maybe the supposed nitriding isn't actually hardening the surface layer of the steel and that's why the barrel wore so quickly? Either way, I'm almost completely sure I'll never buy another Faxon product, and forever warn others to stay away!
I agree. It was on sale for $109 at brownells so I picked it up. I am not impressed at how simple it was to go straight through the nitride. I used a $3 colbalt bit and no cutting oil and it went through like butter.
I won't say their statement is ridiculous, but....
My Faxon was an AIM one that had the cross pin already drilled, I chose not to dimple because of that?
Think I made a mistake?
A factory pinned block does not need to be dimpled after the fact.
My Faxon was an AIM one that had the cross pin already drilled, I chose not to dimple because of that?
Think I made a mistake?
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