Page 6 of 10 FirstFirst ... 45678 ... LastLast
Results 51 to 60 of 92

Thread: Masking Tape just ate away KMR's Black finish?

  1. #51
    Join Date
    Jan 2012
    Posts
    118
    Feedback Score
    0
    Quote Originally Posted by Obscenejesster View Post
    I suppose its easy to praise one of the best free float handguards ever made. When you sit back and look at the KMR you can tell how much research and design hours they put into it. They didn't just make something that looked different from what's currently on the market. They designed something that performed better as well.

    Sent from my SM-G900T using Tapatalk
    Its more fun to sit back and wonder if they had some bad tunnel vision. AP custom has made a handguard that weighs the same for half the price for quite a while now. And all AP custom does is buys carbon fiber tubes from Rock West Composites and then machines a barrel nut and mounting slots.

    Quote Originally Posted by donlapalma View Post
    And to add to that, their Lead Engineer, Designer did just show up and educate our asses. There was quite a bit of hypothesizing going down in this thread and the record was set straight. Tells me that they are listening, are concerned and care about the quality of their products. I'm sure there are those who may not be impressed by such a thing, but I, for one, appreciate the proactiveness.
    I seem to recall his post basically saying "its easy to fix our mistake."

  2. #52
    Join Date
    Jan 2010
    Location
    Poland
    Posts
    1,688
    Feedback Score
    0
    Quote Originally Posted by Quiet Riot View Post
    Actually, placing the screws on top of the barrel nut creates significantly different clamping forces than placing the screws underneath because they complete a ring of tension around the nut. When you clamp on the bottom, tension pulls the open gas tube channel down onto the barrel nut, prying it open, which forces the hand guard to make up for this weakness with more material (and weight) in places it isn't otherwise needed.
    Original design has a tab that engages slot in upper receiver that both prevent rotation or pulling top of rail down. Anyway, I do not criticize or dismiss KMR design. I just pointed out that barrel nut and mounting system is not new idea. Changed, maybe improved, but not new.

    BTW What is barrel nut OD in KMR and distance from bore line to top of gas pipe channel? Always have creepy ideas coming to my mind
    Montrala

    I'm sponsored competition shooter representing Heckler&Koch, Kahles, Hornady and Typhoon Defence brands in Poland, so I can be biased

    http://montrala.blogspot.com

  3. #53
    Join Date
    Mar 2013
    Posts
    616
    Feedback Score
    0
    Quote Originally Posted by Freedoooom View Post
    Its more fun to sit back and wonder if they had some bad tunnel vision. AP custom has made a handguard that weighs the same for half the price for quite a while now. And all AP custom does is buys carbon fiber tubes from Rock West Composites and then machines a barrel nut and mounting slots.



    I seem to recall his post basically saying "its easy to fix our mistake."
    Not really a fan of carbon fiber hand guards and proprietary mounting. I'd also rather have direct attach accessories rather than using screws to mount picatinny and then the accessory on top of that.

    By the way, the AP hand guards are not the same weight as the KMR. The advertised weight you're looking at on their website is for just the hand guard. It isn't including the barrel nut and mounting hardware. If you compare apples to apples then the weight of the 13" KMR without the barrel nut is 5.6 ounces. Compare that to AP's 12" hand guard that weighs in at 7.8 ounces. Of course this is only comparing the weight of each handguard which is only one of the considerations when comparing hand guards. Beyond the advantages Keymod has over AP's proprietary mounting options, the KMR also offers more mounting options. I think the AP hand guards are fine for range use but they aren't really hard use oriented. They use the stock barrel nut with no anti rotation tabs.

    Sent from my Nexus 7 using Tapatalk

  4. #54
    Join Date
    Mar 2013
    Posts
    616
    Feedback Score
    0
    Quote Originally Posted by montrala View Post
    Original design has a tab that engages slot in upper receiver that both prevent rotation or pulling top of rail down. Anyway, I do not criticize or dismiss KMR design. I just pointed out that barrel nut and mounting system is not new idea. Changed, maybe improved, but not new.

    BTW What is barrel nut OD in KMR and distance from bore line to top of gas pipe channel? Always have creepy ideas coming to my mind
    I can't think of any other hand guards that use a barrel nut and lock up method like the KMR. I'm curious though. Can you show us a couple?

    Sent from my Nexus 7 using Tapatalk

  5. #55
    Join Date
    Jan 2010
    Location
    Poland
    Posts
    1,688
    Feedback Score
    0
    Quote Originally Posted by Obscenejesster View Post
    I can't think of any other hand guards that use a barrel nut and lock up method like the KMR. I'm curious though. Can you show us a couple?
    Original idea is HK416 free float, 4-rails handguard designed ca 2004. Later on it went on HK417 with slightly modified design. When Geissele made their rail upgrade for NSW HK416s (SMR-HK), same mounting method as on HK (actually 2 screw version a'la HK417) went to their SMR series of handguards. Those are designs I had in mind. Of course, KMR has barrel nut with wider slot, to accommodate 2 screws close to each other and mentioned benefits of moving clamping position up with no bottom channel like HK or Geissele rails have, but general idea of barrel nut and interfacing handguard with it is same. New rails for HK MR556A1-SD and MR762A1-SD share general shape with KMR, but still use traditional bottom screw as older HK rails (but they have top tab that "hooks" handguard into upper receiver).
    Montrala

    I'm sponsored competition shooter representing Heckler&Koch, Kahles, Hornady and Typhoon Defence brands in Poland, so I can be biased

    http://montrala.blogspot.com

  6. #56
    Join Date
    Jan 2008
    Posts
    101
    Feedback Score
    0
    Quote Originally Posted by montrala View Post
    Original idea is HK416 free float, 4-rails handguard designed ca 2004. Later on it went on HK417 with slightly modified design. When Geissele made their rail upgrade for NSW HK416s (SMR-HK), same mounting method as on HK (actually 2 screw version a'la HK417) went to their SMR series of handguards. Those are designs I had in mind. Of course, KMR has barrel nut with wider slot, to accommodate 2 screws close to each other and mentioned benefits of moving clamping position up with no bottom channel like HK or Geissele rails have, but general idea of barrel nut and interfacing handguard with it is same. New rails for HK MR556A1-SD and MR762A1-SD share general shape with KMR, but still use traditional bottom screw as older HK rails (but they have top tab that "hooks" handguard into upper receiver).
    As far as handguards go, but the method used (Cross pin/bolt in a grooved feature) is no different than the firing pin retainer on an AR15 or a half dozen other designs. The KAC QD suppressors also used a similar feature for fastening, though with a cross-gate rather than screws or pins. Many pintle mounts have used a similar setup since who-knows-when, with a pin in a groove to retain the pivot mechanism. Point being, it's not a new design nor unique to the 416. The position of the screw over the top of the barrel nut rather than under it is a significant achievement in any case as no one else had yet fit it all and the benefits of doing so are numerous.

  7. #57
    Join Date
    Jan 2010
    Location
    Poland
    Posts
    1,688
    Feedback Score
    0
    Quote Originally Posted by Phreakish View Post
    Point being, it's not a new design nor unique [...].
    And this was a point of my original comment to: "it kinda makes me wonder why nobody else has thought of it". As you pointed, somebody did. Lot of people actually and HK416 handguard is just an example.

    BTW Similar concept is used to fix barrel into receiver in new Polish MSBS rifle. But locking is achieved by two lugs that are fixed to stretching screw (to eliminate need of precise torquing on mounting).
    Montrala

    I'm sponsored competition shooter representing Heckler&Koch, Kahles, Hornady and Typhoon Defence brands in Poland, so I can be biased

    http://montrala.blogspot.com

  8. #58
    Join Date
    May 2014
    Posts
    317
    Feedback Score
    0
    Quote Originally Posted by Phreakish View Post
    As far as handguards go, but the method used (Cross pin/bolt in a grooved feature) is no different than the firing pin retainer on an AR15 or a half dozen other designs. The KAC QD suppressors also used a similar feature for fastening, though with a cross-gate rather than screws or pins. Many pintle mounts have used a similar setup since who-knows-when, with a pin in a groove to retain the pivot mechanism. Point being, it's not a new design nor unique to the 416. The position of the screw over the top of the barrel nut rather than under it is a significant achievement in any case as no one else had yet fit it all and the benefits of doing so are numerous.
    It's a "simple" idea and not a new one at that, but yet no other manufacturer had thought of this when designing their handguards.

    Just like their tool-less KM VG and KM QD sling mount. Simple yet brilliant designs compare to what came before. This is what I love about BCM.

  9. #59
    Join Date
    Jan 2008
    Posts
    101
    Feedback Score
    0
    Quote Originally Posted by montrala View Post
    And this was a point of my original comment to: "it kinda makes me wonder why nobody else has thought of it". As you pointed, somebody did.
    My point was with respect to the screw over the barrel nut rather than under it, thereby eliminating the inherent weak clamping caused by having a channel or other shape within the material that is stressed under clamping. Obviously using a cross-bolt is not new. Our uninterrupted circumference of material around the barrel nut coupled with a cross bolt is the innovation.

  10. #60
    Join Date
    Jan 2010
    Location
    Poland
    Posts
    1,688
    Feedback Score
    0
    Quote Originally Posted by Phreakish View Post
    Our uninterrupted circumference of material around the barrel nut coupled with a cross bolt is the innovation.
    Yes. When I wrote: "Changed, maybe improved", I had exactly this innovation in mind. "Maybe" comes from obvious lack of opportunity to test it and ensure that in real life benefits are same as in theory or at least that befits are worth mentioning.. Especially, because I did not notice any myself, nor had feedback from military users around here about problems coming from handguard design on HK416* (and believe me, those guys are very vocal about anything bad that happens to their 416s).

    * - other than early production, non-captive crossbolt coming loose sometimes, but this seem to be solved long ago.

    However, with how your handguard profile is designed, with like what 345dgr(?) of uniterrupred circumference around barrel nut, there actually is no other (good) place to put cross bolts and tension it around it. So befits or no, this is most logical place to put nuts in your specific design.

    BTW Can you answer my question from previous post: "What is barrel nut OD in KMR and distance from bore line to top of gas pipe channel?" I was wondering if KMR can be somehow forced on 416. You know, men is always stronger than matter!
    Last edited by montrala; 06-11-14 at 18:13.
    Montrala

    I'm sponsored competition shooter representing Heckler&Koch, Kahles, Hornady and Typhoon Defence brands in Poland, so I can be biased

    http://montrala.blogspot.com

Page 6 of 10 FirstFirst ... 45678 ... 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
  •