Over-The-Beach "OTB" FAQ
Page 1 of 3 1 2 3 LastLast
Results 1 to 10 of 26
Like Tree1Likes

Thread: Over-The-Beach "OTB" FAQ

  1. #1
    H&K Certified Armorer
    Chopstix Kid's Avatar
    Join Date : Nov 2007
    Location : Michigan
    Age : 48
    Posts : 8,155
    Mentioned
    10 Post(s)

    Default Over-The-Beach "OTB" FAQ

    Over-The-Beach "OTB" is a capability that, to the best of my knowledge, HK first started to advertise with the G36. It is a capability required by SOCOM in that the firearm must be able to be safely fired immediately after being removed from a body of water. There has been no public release, that I am currently aware, of information regarding OTB and the HK417.

    G36 OTB
    HK G36 Over the Beach Test - YouTube

    HK416 OTB
    HK (Heckler & Koch) versus Colt - YouTube


    1) Regardless of what you read or what you see on YouTube, the MR556 and MR762 are *NOT* OTB capable based on HK's design specfications for OTB. While you may find many of the visible OTB features on the MR-series (visible being the operative word here), I have asked the question directly and have been answered directy by HK that they are not OTB capable.

    1) Not all HK416's are OTB capable. OTB capability must be specified at time of order.

    2) Most LE guns are not ordered as OTB capable because of the ammunition restrictions with OTB guns.

    3) Aside from the several visible OTB features, I am told that there are several non-visible features of OTB guns whose details are not currently publicly available. I can only assume that this may include but is not limited to additional drainways and possible metallurgical differences.

    4) Barrel profile is not a determining factory of OTB capability

    5) There are three features found on many MR556's and HK416's which are common to the OTB guns. The presense of these features does constitute the firearm as being OTB capable. They are as follows:

    • Three drain holes at the rear of the receiver extension (buffer tube)
    • Extractor support lug in the barrel extension
    • Minimal chamfur on the chamber face for added casing support


    I'll end it with that as I do not readily have photos available. If not get posted by other members, I'll post some up the next time I have opportunity.
    gtabbal likes this.
    Dakota Tactical (07/C2)
    H&K Certified Armorer
    B&T Master Dealer
    Roller Locks Made Right(TM)

    Looking for a Nanuk case?
    Enjoy 15% off site wide at Hidden Content
    Use code: JSTOP15

    Hidden Content
    Hidden Content
    Hidden Content
    Hidden Content
    Hidden Content


    War does not determine who is right - only who is left. ~ Bertrand Russell

    Hidden Content

  2. #2
    Senior Member

    Join Date : Apr 2010
    Posts : 108
    Mentioned
    0 Post(s)

    Default

    Hmm, my 416 has the other stuff. Not sure about the chamber face. Here is a pic.


  3. #3
    H&K Certified Armorer
    Chopstix Kid's Avatar
    Join Date : Nov 2007
    Location : Michigan
    Age : 48
    Posts : 8,155
    Mentioned
    10 Post(s)

    Default

    John, no, you do not have an OTB-style chamber face. The chamfur on your is very large which was intended to help assist in the feeding of various ammunition types. I have an OTB HK416 upper. I'll get a photo of the chamber face sometime this week unless someone posts one first. I did find one on Google images but it was tough to see unless you knew specifically what to look for.

  4. Remove Advertisements
    HKPro.com
    Advertisements
     

  5. #4
    Banned

    Join Date : Jun 2004
    Posts : 4,248
    Mentioned
    0 Post(s)

    Default

    Quote Originally Posted by Chopstix Kid View Post
    John, no, you do not have an OTB-style chamber face. The chamfur on your is very large which was intended to help assist in the feeding of various ammunition types. I have an OTB HK416 upper. I'll get a photo of the chamber face sometime this week unless someone posts one first. I did find one on Google images but it was tough to see unless you knew specifically what to look for.
    From what I remember, if there appears to be almost no obvious chamfur, it's the OTB spec.




  6. #5
    Gets the Shakes if No HK Contact in 24 Hour Period
    ptoguy's Avatar
    Join Date : Jul 2007
    Location : 4th floor, Cubicle #K32
    Posts : 893
    Mentioned
    0 Post(s)

    Default

    From G3Kurz:
    WARNING!!!
    The HK rifle IS NOT OTB qualified unless HK has tested it as such. To my knowledge they have not. There would be no reason really why a civilian needs that capability in a sporting rifle. Standard safety rules are never to fire the rifle with an obstructed bore which of course includes water (or worse the air bubble that gets trapped by the water inside the bore). If you have seen "the Competitive Model" in the YouTube video HK416 vs M4 - YouTube come apart (upper receiver top launches from the rifle) the end result can be death, at a minumum serious injury. With a rash of "home testers" pushing their HK's to the limit recently with little or no knowledge of the dangers and protocol of conducting such tests it is possible someone will eat forged aluminum somewhere along the way.

    The OTB feature/capability is a very unique capability that was requested by one particular user base that operates out of the surf. The time it takes to ford (drain) the bore before firing is short but could make the difference in the operators ability to immediately engage targets as they break the surface. HK developed it carefully initially using remote firing rigs long before man firing and numerous changes were made along the way after careful inspection of test samples.

    The HK416 OTB features include drain holes in the bolt carrier, buffer tube and buttstock. More importantly they also possess a unique barrel extension with limit pin that prevents the overtravel of the extractor during OTB use. MOST importantly they use the HK-unique cold hammer forged barrel and material that has the proven capability to withstand such excessive forces caused by such use and abuse. The US MR556A1 barrel is made by HK GmbH as a blank and shipped to the US where it is finished not by HK. It also has a profile that differs from that of the HK416 so it is not the same and likely the final and unique induction hardening step applied to HK GmbH-produced barrels is skipped or done differently. An MR556A1 IN NOT an HK416 and an HK416 is not an HK416 OTB.

    Beware. OTB function testing by novices is hazardous to ones health.

    G3Kurz
    Thread: https://www.hkpro.com/forum/hk416-hk4...ml#post1080734

  7. #6
    H&K Certified Armorer
    Chopstix Kid's Avatar
    Join Date : Nov 2007
    Location : Michigan
    Age : 48
    Posts : 8,155
    Mentioned
    10 Post(s)

    Default

    Quote Originally Posted by pointblank4445 View Post
    From what I remember, if there appears to be almost no obvious chamfur, it's the OTB spec.
    Exactly. But as G3kurz said, that does not make it an OTB barrel unless it was specifically tested and stated by HK.

  8. #7
    Senior Member

    Join Date : Apr 2010
    Posts : 108
    Mentioned
    0 Post(s)

    Default

    Quote Originally Posted by Chopstix Kid View Post
    John, no, you do not have an OTB-style chamber face. The chamfur on your is very large which was intended to help assist in the feeding of various ammunition types. I have an OTB HK416 upper. I'll get a photo of the chamber face sometime this week unless someone posts one first. I did find one on Google images but it was tough to see unless you knew specifically what to look for.
    Ok thanks! Nice to know not to fire my gun underwater now :)

  9. #8
    Desperately Needs Treatment
    M995's Avatar
    Join Date : May 2010
    Location : Canada
    Posts : 1,263
    Mentioned
    0 Post(s)

    Default

    From what G3 kurz has said some HK417s have OTB capability (which have been requested by specific customers) but not all 417 variants are OTB rated. https://www.hkpro.com/forum/hk416-hk4...apability.html

  10. #9
    Senior Member
    Slackavelli's Avatar
    Join Date : Sep 2012
    Posts : 142
    Mentioned
    0 Post(s)

    Default

    Thanks for this thread. Obviously much needed. lol

  11. #10
    Unrepentant HKHolic
    Montrala's Avatar
    Join Date : Nov 2003
    Location : Poland
    Age : 48
    Posts : 3,411
    Mentioned
    32 Post(s)

    Default

    Regarding HK416 and OTB, per info I got from HK, since HK416A2 all variants are OTB rated. Actually "A2" designation was given when OTB became standard feature (A1 was given when firing pin safety was added). Before "A2" OTB was "special order feature".

    BTW OTB applies only to complete rifles, so "A2" upper on other lower is not OTB. Probably there will be no catastrophic event, because all parts responsible for that are in upper, but there will not be either basic or extended function from/in water.
    Last edited by Montrala; 10-26-2012 at 12:01 PM.
    Hidden Content Hidden Content
    Current: SFP9SD-SF, P2000SK, MR223A3 11.5"
    Past: P30L, P2000, P30, P7M13, Expert, G3 (MKE T41), HK45C, MR223 16.5"/14.5", SFP9-SF
    I'm sponsored competition shooter representing Heckler&Koch, Hornady, Khales & Typhoon Defence brands in Poland

Page 1 of 3 1 2 3 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
  •  

Search tags for this page

hk 416 otb

,
hk otb
,

hk416 otb

,
otb capability
,
otb gun
,

otb rifle

,

over the beach

,
over the beach (otb)
,

over the beach (otb) capability

,

over the beach capability

,
over the beach capable
,

over the beach test

Click on a term to search for related topics.