Anyone actually have data on a 10" with AGB? - Page 3
Page 3 of 4 FirstFirst 1 2 3 4 LastLast
Results 21 to 30 of 32
Like Tree7Likes

Thread: Anyone actually have data on a 10" with AGB?

  1. #21
    Unrepentant HKHolic
    RegularGuy461969's Avatar
    Join Date : Mar 2015
    Location : By the Great Shell Bay
    Posts : 2,726
    Mentioned
    46 Post(s)

    Default

    Quote Originally Posted by Chesapeak610 View Post
    Here's what I got so far:

    Attachment 245950

    The case ejection is listed as a time position; Example 3:00 o'clock = 3:00oC
    All of my installs have been in OEM 416 chrome lined barrels.
    "Just because you're paranoid doesn’t mean they're not after you!"

  2. #22
    Very Senior Member
    InshallahTech's Avatar
    Join Date : Aug 2013
    Location : WA
    Posts : 389
    Mentioned
    15 Post(s)

    Default

    Quote Originally Posted by RegularGuy461969 View Post
    Ditto for me. IT actually did the 416 barrel gas port tuning for mine and installed the vented gas blocks on three uppers for me. I believe he ended up taking the barrel gas port from 1.5mm (standard on a non vented 10’4” barrel IIRC) and openned to 1.6mm-1.7mm.
    Your ports were 1.4mm, opened up to either 1.5 or 1.6mm. Can't remember off the top of my head exactly. I know I test fired to ensure perfect function though, prior to return.

    I'm very happy they work well for you!
    Last edited by InshallahTech; 11-20-2019 at 09:10 AM.
    RegularGuy461969 likes this.

  3. #23
    Unrepentant HKHolic
    RegularGuy461969's Avatar
    Join Date : Mar 2015
    Location : By the Great Shell Bay
    Posts : 2,726
    Mentioned
    46 Post(s)

    Default

    [QUOTE=InshallahTech;3609464]
    Quote Originally Posted by RegularGuy461969 View Post
    Ditto for me. IT actually did the 416 barrel gas port tuning for mine and installed the vented gas blocks on three uppers for me. I believe he ended up taking the barrel gas port from 1.5mm (standard on a non vented 10’4” barrel IIRC) and openned to 1.6mm-1.7mm.
    QUOTE]

    Your ports were 1.4mm, opened up to either 1.5 or 1.6mm. Can't remember off the top of my head exactly. I know I test fired to ensure perfect function though, prior to return.

    I'm very happy they work well for you!
    Copy that and thanks for the correction. I like what @Chesapeak610 is putting together. Glad he’s getting accurate info. I’ll look and see if I can track down precisely and post if I find it.
    InshallahTech likes this.

  4. Remove Advertisements
    HKPro.com
    Advertisements
     

  5. #24
    Junior Member

    Join Date : Jun 2019
    Posts : 32
    Mentioned
    2 Post(s)

    Default

    Updated chart based on @RegularGuy461969 & @InshallahTech input.

    Anyone actually have data on a 10" with AGB?-10.4-gas-block-info.jpg

  6. #25
    Junior Member

    Join Date : Jun 2019
    Posts : 32
    Mentioned
    2 Post(s)

    Default

    Updated chart: Added a Key to the chart.

    Anyone actually have data on a 10" with AGB?-10.4-gas-block-info.jpg

  7. #26
    Junior Member

    Join Date : Dec 2018
    Location : FL
    Posts : 32
    Mentioned
    3 Post(s)

    Default

    I've done a bunch of searching on the forum here before I started this thread and it seems like what ends up "confusing" the issue is items that are sold as one thing but don't have the dimensions that match what comes on factory uppers. But I know that discussion started a whole ****-storm earlier. It also seems like some people are measuring a 10.4 gas block as "1mm" when the OEM one is (according to many posts here) .89-.9mm. That's NOT to say that what's being measured isn't 1mm, but I think it again confuses the issue.

    Quote Originally Posted by InshallahTech View Post
    I've an AGB that i'm working on for a member here and I just got some measurements from it.

    The vent is just about .9mm and the port sizes on the switch are 1.1mm and 1.8mm.

    The 1.8mm is a wash since the gas will be fully controlled by the barrel gas port so the 1.8mm allows full through flow and the 1.6mm barrel port would be restricted to the 1.1mm of the suppressed settings.

    Others have listed the suppressed port at 1mm.
    Interesting, and a setting of 1.1mm suppressed could be really helpful, it would seem. The one I received from Brownells kit has a .9mm vent, but haven't measured the internal ports. This kind of makes me interested in in trying it now. Thanks for the additional info.

    Chesapeake, this probably doesn't help with what you're trying to do, but my factory 14.5" has a 1.5mm vent. Definitely bigger than the 10.4 ports everyone is quoting. Works perfectly suppressed or unsuppressed with Federal M193 and a SOCOM RC and OEM spring/buffer.

  8. #27
    Junior Member

    Join Date : Jun 2019
    Posts : 32
    Mentioned
    2 Post(s)

    Default

    Hey Gatordev, I started down the path of collecting that info as well, but it’s just too much and varies from gun to gun. I have an MR556 16.5” upper that has a 1.45mm (.057”) vent which probably qualifies as a 1.5mm... I also have a VGB that came with my Brownells HK416 kit and that has a 1.7mm (.067”) vent, though I don’t know what the donor barrel was because that wasn’t included (nor was the bolt or lower receiver). So, I’m just sticking with 10.4” because that seemed to be the big unknown, especially for AGBs.

    I’ll also say I’m still a bit perplexed, ToyCop has a 10.4” barrel with a 1.6mm port and an AGB with a 1.6mm N (Normal) port and a 0.9mm Vent and his operates fine with the HK buffer spring and buffer. Yet my 10.4” with a 1.7mm barrel port and an AGB with a 1.7mm N port and a 0.9mm Vent is under-gassed…even though the barrel and N ports are larger; WTH?? It must be something to do with the barrels then…

    I suppose if we get more 10.4”/AGB samples, we’ll be able to state something that’s repeatable and anyone trying to use an AGB with a 10.4” barrel will have a workable formula. Or, they go the VGB route with a 1.0mm vent and it works; though that’s just too easy.

    Or…”and then magic happens…”

  9. #28
    Premium Professional

    Join Date : Apr 2017
    Location : Michigan
    Posts : 282
    Mentioned
    5 Post(s)

    Default

    Quote Originally Posted by Chesapeak610 View Post
    Hey Gatordev, I started down the path of collecting that info as well, but it’s just too much and varies from gun to gun. I have an MR556 16.5” upper that has a 1.45mm (.057”) vent which probably qualifies as a 1.5mm... I also have a VGB that came with my Brownells HK416 kit and that has a 1.7mm (.067”) vent, though I don’t know what the donor barrel was because that wasn’t included (nor was the bolt or lower receiver). So, I’m just sticking with 10.4” because that seemed to be the big unknown, especially for AGBs.

    I’ll also say I’m still a bit perplexed, ToyCop has a 10.4” barrel with a 1.6mm port and an AGB with a 1.6mm N (Normal) port and a 0.9mm Vent and his operates fine with the HK buffer spring and buffer. Yet my 10.4” with a 1.7mm barrel port and an AGB with a 1.7mm N port and a 0.9mm Vent is under-gassed…even though the barrel and N ports are larger; WTH?? It must be something to do with the barrels then…

    I suppose if we get more 10.4”/AGB samples, we’ll be able to state something that’s repeatable and anyone trying to use an AGB with a 10.4” barrel will have a workable formula. Or, they go the VGB route with a 1.0mm vent and it works; though that’s just too easy.

    Or…”and then magic happens…”
    I wonder if part of the issue may be with who does the barrel work. Just drilling the port larger doesn’t necessarily mean that it is top dead center like it should be. I would think most places that offer barrel services would be smart enough to check this, but Ive seen plenty of barrels that were chopped and threaded and the threads weren’t concentric with the bore.

  10. #29
    Junior Member

    Join Date : Jun 2019
    Posts : 32
    Mentioned
    2 Post(s)

    Default

    Good point. The barrel was supplied by Hurricane Butterfly and made by Lothar Walther. My assumption is that the port would align precisely with the gas block port, but if it doesn't, my 1.7mm is moot. I've got to figure out how to check that. Again, good thinking, that never crossed my mind!

    BTW, I'm going to start a new post called "HK416/MR556 10.4” Barrels/Gas Block Configurations that Worked" and supply the table and invite others to contribute. I just read the Nefarious Arms post "WTS HK416 10.4" Vented gas block" and someone said "We desperately need an informational thread capturing all the gas block and gas port info"; I'll give it a shot...

  11. #30
    Very Senior Member
    InshallahTech's Avatar
    Join Date : Aug 2013
    Location : WA
    Posts : 389
    Mentioned
    15 Post(s)

    Default

    Quote Originally Posted by Chesapeak610 View Post
    I’ll also say I’m still a bit perplexed, ToyCop has a 10.4” barrel with a 1.6mm port and an AGB with a 1.6mm N (Normal) port and a 0.9mm Vent and his operates fine with the HK buffer spring and buffer. Yet my 10.4” with a 1.7mm barrel port and an AGB with a 1.7mm N port and a 0.9mm Vent is under-gassed…even though the barrel and N ports are larger; WTH?? It must be something to do with the barrels then…
    I think for these purposes, only HK Factory barrels and HK factory gas blocks with HK factory buffers/springs should be considered.

    I simply don't trust ANY after market manufacturer of HK parts for the reasons listed above. Improper porting, obvious distain for the factory R&D and established protocol, poor QA/QC, and ignorance of all the factors involved in this particular operating system.

    The addition of aftermarket parts only serves to muddy the waters and skew the results.

Page 3 of 4 FirstFirst 1 2 3 4 LastLast

Sponsored Links

 
 

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •