PTR 9KT roller bumps - Page 3
Page 3 of 4 FirstFirst 1 2 3 4 LastLast
Results 21 to 30 of 37
Like Tree7Likes

Thread: PTR 9KT roller bumps

  1. #21
    Desperately Needs Treatment
    rickj1nd's Avatar
    Join Date : Mar 2011
    Posts : 1,260
    Mentioned
    4 Post(s)

    Default

    Quote Originally Posted by GTS197 View Post
    Since it’s a popular discussion, I have the 9CT. Does the full size require a different one?
    No... The full size MP5 is good to go with the standard 100° locking piece, suppressor and 147gr's.

  2. #22
    HKPRO Professional
    GTS197's Avatar
    Join Date : Apr 2007
    Location : TX
    Posts : 239
    Mentioned
    2 Post(s)

    Default

    Quote Originally Posted by rickj1nd View Post
    No... The full size MP5 is good to go with the standard 100° locking piece, suppressor and 147gr's.
    Talked to PTR today. They said to use 80*, and recommended the HK over the RCM (said the RCM was built to a lesser tolerance and could cause premature headspace issues). When inquired into they’re bolt head not working with other locking pieces, I was told that if it didn’t work they’d supply me with another bolt head. He said the HK locking piece would be tight, but should work. Does that information sound accurate?

    If I stay with the factory 100*, would that be good to go with the 158gr subsonic loads?
    If you can't be safe...be deadly.

  3. #23
    HKPRO PREMIUM PARTNER
    bangbangduck's Avatar
    Join Date : May 2018
    Posts : 111
    Mentioned
    1 Post(s)

    Default

    Since spotting these bumps, I've done a fair amount of research into possible causes and the locking pieces. It appears that changing locking pieces for suppressor use is only relevant to the mp5k.

    That being said, I ran 150 rds through it (no suppressor), and I'm still getting excessive bolt velocity with the new, stiffer recoil spring. Kicks like a mule (relative to the full size mp5 I had on hand today) and the lower rear stock pin was starting to work itself out. Bolt is already marking up the buffer pretty good. This is using 124gr PMC FMJ and Federal TSJ.

    Last time I checked, the bolt gap was at 1300 rds and it was exactly 0.016"

    I'll check it again tomorrow after giving it a good cleaning.

    I'm still waiting on the 80° locking piece from hkparts. We'll see how that goes...
    BulkHead likes this.

  4. Remove Advertisements
    HKPro.com
    Advertisements
     

  5. #24
    Junior Member
    AValdesJr's Avatar
    Join Date : Sep 2019
    Posts : 7
    Mentioned
    0 Post(s)

    Default

    Wow, just picked up my PTR MP5K, this form was very informative is this a common problem with these guns. If so how can you prevent this from happening.

  6. #25
    Desperately Needs Treatment
    rickj1nd's Avatar
    Join Date : Mar 2011
    Posts : 1,260
    Mentioned
    4 Post(s)

    Default

    Quote Originally Posted by GTS197 View Post
    Talked to PTR today. They said to use 80*, and recommended the HK over the RCM (said the RCM was built to a lesser tolerance and could cause premature headspace issues). When inquired into they’re bolt head not working with other locking pieces, I was told that if it didn’t work they’d supply me with another bolt head. He said the HK locking piece would be tight, but should work.
    They said RCM is built to a lesser tolerance, then go on to say an HK locking piece may be tight in their bolthead and would replace it cause the conclusion would be that it was essentially out of spec... LMAO
    (Does TB run the warranty dept at PTR now?) LMAO again.
    Last edited by rickj1nd; 09-21-2019 at 12:06 PM.
    gt40doc likes this.

  7. #26
    HKPRO Professional
    GTS197's Avatar
    Join Date : Apr 2007
    Location : TX
    Posts : 239
    Mentioned
    2 Post(s)

    Default

    Quote Originally Posted by rickj1nd View Post
    They said RCM is built to a lesser tolerance, then go on to say an HK locking piece may be tight in their bolthead and would replace it cause the conclusion would be that it was essentially out of spec... LMAO
    (Does TB run the warranty dept at PTR now?) LMAO again.
    Decided to reach out to Marine0303, and eliminate the riff-raff. He said that the factory 100* LP is fine for running a can. Looks like I'll be leaving it alone after all.

  8. #27
    The Librarian
    Oicani's Avatar
    Join Date : Feb 2013
    Location : PA
    Posts : 5,201
    Mentioned
    64 Post(s)

    Default

    Surprised nobody has mentioned checking bolt gap.
    "...but just like every other clone, they are copies of the original and copies are never as good as the original."

  9. #28
    Desperately Needs Treatment
    rickj1nd's Avatar
    Join Date : Mar 2011
    Posts : 1,260
    Mentioned
    4 Post(s)

    Default

    Quote Originally Posted by GTS197 View Post
    Decided to reach out to Marine0303, and eliminate the riff-raff. He said that the factory 100* LP is fine for running a can. Looks like I'll be leaving it alone after all.
    The definitive application of the HK locking pieces in your query was clarified by Jim Schatz years ago... which would "eliminate" ALL the "riff-raff".

  10. #29
    Gets the Shakes if No HK Contact in 24 Hour Period

    Join Date : Mar 2012
    Location : Mid Atlantic states
    Posts : 577
    Mentioned
    2 Post(s)

    Default

    Another suggestion, please check your cocking tube gap. Set up the gun for checking bolt gap (release bolt, drop hammer) but check the gap between the carrier and your cocking lever support. Optimal should be your bolt gap plus 15, so you are at 16 for bolt gap so optimal would be 31.

    If there is no cocking tube gap for it then your bolt gap may not be a real number.
    Last edited by gulfstategaurd; 09-23-2019 at 08:39 PM.

  11. #30
    HKPRO Professional
    GTS197's Avatar
    Join Date : Apr 2007
    Location : TX
    Posts : 239
    Mentioned
    2 Post(s)

    Default

    Quote Originally Posted by rickj1nd View Post
    They said RCM is built to a lesser tolerance, then go on to say an HK locking piece may be tight in their bolthead and would replace it cause the conclusion would be that it was essentially out of spec... LMAO
    (Does TB run the warranty dept at PTR now?) LMAO again.
    You guys were right, absolutely.

    I don't even know why I bother with contacting manufacturers. This isn't the first time they were a bit off on their information.

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
  •