Page 11 of 31 FirstFirst ... 91011121321 ... LastLast
Results 101 to 110 of 310

Thread: BRT 16" OPTIMUM Barrel w/ Extended Length Gas System

  1. #101
    Join Date
    Oct 2007
    Posts
    6,611
    Feedback Score
    11 (100%)
    Quote Originally Posted by elephantrider View Post
    I seem to recall reading that some of the FN hammer forged barrels had some taper to them. I would assume that the port would start to erode before the bore would get worn away.
    This is correct and they do, and the mandrel has nothing to do with it. I am not sure how public their process is, so I digress, but the bore ID does have a very very slight taper to it, not as a product of forging, though, on some of the barrels fn supplies.

  2. #102
    Join Date
    Apr 2009
    Location
    FL -Where it's summer 10.5 months out of the year
    Posts
    4,114
    Feedback Score
    17 (100%)
    Quote Originally Posted by WS6 View Post
    This is correct and they do, and the mandrel has nothing to do with it. I am not sure how public their process is, so I digress, but the bore ID does have a very very slight taper to it, not as a product of forging, though, on some of the barrels fn supplies.
    How would one impart a taper to a CHF bore without the mandrel being tapered?

    Note: I already know the answer.

    EDIT: For clarity, not all CHF barrels have a taper, but the ones that do, receive that slight bore taper from the actual CHF process, and not afterward. See Centurion's website:

    "Cold Hammer Forged Barrels

    Hammer forging is a process in which a drilled, reamed and honed blank has the rifling formed into it by placing the barrel blank on a mandrel that has the rifling ground into its outer surface. The blank and mandrel are then placed between two opposing power hammers and the blank is beaten around the mandrel leaving the rifling pattern in the barrel. This process leaves an extremely smooth and consistent surface on the inside of the barrel, that lends itself to excellent accuracy. The forging process also work hardens the barrel steel causing a very durable and much longer lasting barrel. Our barrels have a slight taper to the bore during the hammer forging process to ensure better accuracy
    ."

    More info, from a professor at Purdue University.

    http://www.vsms.org/Forum/Seite_34_forget-barrels/S34.htm
    Last edited by BufordTJustice; 11-21-16 at 08:55.
    "That thing looks about as enjoyable as a bowl of exploding dicks." - Magic_Salad0892

    "The body cannot go where the mind has not already been."

  3. #103
    Join Date
    Jun 2006
    Location
    GA
    Posts
    3,704
    Feedback Score
    43 (100%)
    Quote Originally Posted by WS6 View Post
    This is correct and they do, and the mandrel has nothing to do with it. I am not sure how public their process is, so I digress, but the bore ID does have a very very slight taper to it, not as a product of forging, though, on some of the barrels fn supplies.
    I recall Centurion touting the tapered bore when they first hit the scene.
    Quote Originally Posted by BufordTJustice View Post
    How would one impart a taper to a CHF bore without the mandrel being tapered?

    Note: I already know the answer.
    I have no idea. Please, do tell.

    Sent from my SM-G920V using Tapatalk

  4. #104
    Join Date
    Apr 2009
    Location
    FL -Where it's summer 10.5 months out of the year
    Posts
    4,114
    Feedback Score
    17 (100%)
    Quote Originally Posted by mtdawg169 View Post
    I recall Centurion touting the tapered bore when they first hit the scene.

    I have no idea. Please, do tell.

    Sent from my SM-G920V using Tapatalk
    See above.
    "That thing looks about as enjoyable as a bowl of exploding dicks." - Magic_Salad0892

    "The body cannot go where the mind has not already been."

  5. #105
    Join Date
    Oct 2007
    Posts
    6,611
    Feedback Score
    11 (100%)
    Quote Originally Posted by BufordTJustice View Post
    How would one impart a taper to a CHF bore without the mandrel being tapered?

    Note: I already know the answer.

    EDIT: For clarity, not all CHF barrels have a taper, but the ones that do, receive that slight bore taper from the actual CHF process, and not afterward. See Centurion's website:

    "Cold Hammer Forged Barrels

    Hammer forging is a process in which a drilled, reamed and honed blank has the rifling formed into it by placing the barrel blank on a mandrel that has the rifling ground into its outer surface. The blank and mandrel are then placed between two opposing power hammers and the blank is beaten around the mandrel leaving the rifling pattern in the barrel. This process leaves an extremely smooth and consistent surface on the inside of the barrel, that lends itself to excellent accuracy. The forging process also work hardens the barrel steel causing a very durable and much longer lasting barrel. Our barrels have a slight taper to the bore during the hammer forging process to ensure better accuracy
    ."
    Interesting that Centurion claims that, as I know where they get their barrels, and that's not when the tapering happens. Watch this video and you tell me if a mandrel is physically capable of creating a taper in this bore:


    Ask yourself how the @3" long mandrel (shown at 1:17) could POSSIBLY create a taper in a 16" barrel...
    Last edited by WS6; 11-21-16 at 08:59.

  6. #106
    Join Date
    Apr 2009
    Location
    FL -Where it's summer 10.5 months out of the year
    Posts
    4,114
    Feedback Score
    17 (100%)
    Quote Originally Posted by WS6 View Post
    Interesting that Centurion claims that, as I know where they get their barrels, and that's not when the tapering happens. Watch this video and you tell me if a mandrel is physically capable of creating a taper in this bore:


    Ask yourself how the @3" long mandrel (shown at 1:17) could POSSIBLY create a taper in a 16" barrel...
    You're serious? That's a chamber mandrel.

    In the video below, 2:46 in shows ACTUAL full bore mandrels.

    Notice their length.

    https://www.youtube.com/watch?v=oALJDh43K3I



    AND see the mandrel at 1:22 in this video....note also the lack of a chamber and how one might be able to alter the number of hammer strikes per barrel location within the hammer machine to create a tighter bore-to-mandrel fit or a LOOSER bore to mandrel fit.

    https://www.youtube.com/watch?v=8pzL5h2cl80


    Additionally, at 3:38, this states that the barrel blank is "roughly .2 millimeters larger than the mandrel", and "the cross sectional area reduction going from blank to mandrel is about 25%-40%."

    https://www.youtube.com/watch?v=dC7pWfM3ngU
    Last edited by BufordTJustice; 11-21-16 at 09:28.
    "That thing looks about as enjoyable as a bowl of exploding dicks." - Magic_Salad0892

    "The body cannot go where the mind has not already been."

  7. #107
    Join Date
    Oct 2007
    Posts
    6,611
    Feedback Score
    11 (100%)
    Quote Originally Posted by BufordTJustice View Post
    You're serious? That's a chamber mandrel. I'm kinda disappointed that you thought one could get any kind of full-bore off of that chamber mandrel.


    In the video below, 2:46 in shows ACTUAL full bore mandrels.

    Notice their length.

    https://www.youtube.com/watch?v=oALJDh43K3I
    Why does the chamber mandrel I showed you a video of have grooves and lands? (yes it's a chamber mandrel, I'm curious about why it's rifled as well)

    Why did the video you link me to also show mandrels with only 2-3" of grooves and lands (please watch your own video at 3:17)?

    Do you think that the mandrel is at/over the length of the barrel, and this whole length contains rifling, which the barrel is pounded around? If so, you're mistaken. Only a small section of the mandrel has rifling, and this section is traversed by the bore while hammers strike it around said small section. This is why it is literally impossible to hammer forge a taper into a bore. The actual rifled part of the mandrel is only a few inches long. In both your video, and mine...
    Last edited by WS6; 11-21-16 at 09:30.

  8. #108
    Join Date
    Apr 2009
    Location
    FL -Where it's summer 10.5 months out of the year
    Posts
    4,114
    Feedback Score
    17 (100%)
    Quote Originally Posted by WS6 View Post
    Why does the chamber mandrel I showed you a video of have grooves and lands?

    Why did the video you link me to also show mandrels with only 2-3" of grooves and lands (please watch your own video at 3:17)?

    Do you think that the mandrel is at/over the length of the barrel, and this whole length contains rifling, which the barrel is pounded around? If so, you're mistaken. Only a small section of the mandrel has rifling, and this section is traversed by the bore while hammers strike it around said small section. This is why it is literally impossible to hammer forge a taper into a bore. The actual rifled part of the mandrel is only a few inches long. In both your video, and mine...
    Requote:
    Additionally, at 3:38, this states that the barrel blank is "roughly .2 millimeters larger than the mandrel", and "the cross sectional area reduction going from blank to mandrel is about 25%-40%."

    https://www.youtube.com/watch?v=dC7pWfM3ngU
    "That thing looks about as enjoyable as a bowl of exploding dicks." - Magic_Salad0892

    "The body cannot go where the mind has not already been."

  9. #109
    Join Date
    Jan 2013
    Posts
    161
    Feedback Score
    3 (100%)
    This is from an old WEVO thread about Centurion's barrels where Monty chimed in about the tapered bore. Hopefully this answers any questions and we can get back on track.

    Last edited by AAMP84; 11-21-16 at 11:43.

  10. #110
    Join Date
    Nov 2010
    Location
    MI
    Posts
    3,055
    Feedback Score
    21 (100%)
    Quote Originally Posted by AAMP84 View Post
    This is from an old WEVO thread about Centurion's barrels where Monty chimed in about the tapered bore. Hopefully this answers any questions and we can get back on track.
    Clear info from an authoritative source.

    Thank you.
    Black River Tactical
    BRT OPTIMUM HFCL Barrels - Hammer Forged Chrome Lined 11.5", 12.5", 14.5"
    BRT OPTIMUM Barrels - 16" MPR, 14.5" MPC, 12.5" MRC, 11.5" CQB, 9" PDW
    BRT EZTUNE Preset Gas Tubes - CAR and MID
    BRT Covert Comps 7.62, 5.56, 6X, 9mm
    BRT MarkBlue Gas Tubes - BRT EXT, EXC and PDW Lengths
    BRT MicroPin Gas Blocks - .750" & .625"
    BRT MicroTUNE Adjustable Gas Blocks
    BRT CustomTUNE Gas Ports

Page 11 of 31 FirstFirst ... 91011121321 ... LastLast

Bookmarks

Posting Permissions

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