Page 3 of 5 FirstFirst 12345 LastLast
Results 21 to 30 of 48

Thread: New purchases

  1. #21
    Join Date
    Oct 2010
    Location
    Oklahoma City
    Posts
    4,149
    Feedback Score
    18 (100%)
    Quote Originally Posted by DeAdeYE15 View Post
    I've got a buddy that swears by PSA. I've been looking at their lowers as well. I'm sure yours is good-to-go. Have fun with it, keep us updated if you have any problems. PSA might make it on the chart before long seems like the parts quality is there.
    Just have to check on PSA closely though. Sometimes they don't have the MPI/HPT bolts or barrels, sometimes they do.

    Just read the specs on whatever you happen to be buying first before you pull the trigger. Otherwise, they are good to go.
    Experience is a cruel teacher, gives the exam first and then the lesson.

  2. #22
    Join Date
    Apr 2010
    Posts
    69
    Feedback Score
    0
    Absolutely nothing broken on my rifles but I do resemble an "unfortunate soul" now and then

    Air, it's a 30mm 6x24 Osprey scope and while decent enough I'll probably install one of my Super snipers on the rifle if it proves accurate enough while shooting it for the first time today. Also, I installed an old red dot Bushnell scope I had laying around for quick acquisition, it works well because it's canted to the left of center thus allowing left eye aim and/or right eye on the larger scope, if bot eyes remain open. I am hopeful that I'll be able to zero it to the right enough to appropriately shift POA/POI.

    Vegas, why goofy look? I liked the purposeful, embedded larger trigger guard, sling attachment, and the shape of the Stark grip that's why I bought & installed it. Only thing different I'd do with them while manufacturing is to rubberize them more.

    I also polished the trigger group to drop it from an 8lb to a now very crisp 5.5-6lb trigger pull.

    So there appears to be an AR manufacturers chart somewhere that we all must worship? Typical of the "follower" mentality crowd....pun intended.

    A few more pics from this morning:


    Last edited by gcp; 07-20-13 at 06:02.

  3. #23
    Join Date
    Apr 2010
    Posts
    69
    Feedback Score
    0
    Quote Originally Posted by Grand58742 View Post
    Just have to check on PSA closely though. Sometimes they don't have the MPI/HPT bolts or barrels, sometimes they do.

    Just read the specs on whatever you happen to be buying first before you pull the trigger. Otherwise, they are good to go.
    Grand, can you please elaborate? What is MPI/HPT? My upper came without the BCG so I bought and installed a Spikes.
    Last edited by gcp; 07-20-13 at 05:59.

  4. #24
    Join Date
    Oct 2010
    Location
    Oklahoma City
    Posts
    4,149
    Feedback Score
    18 (100%)
    Quote Originally Posted by gcp View Post
    Grand, can you please elaborate? What is MPI/HPT? My upper came without the BCG so I bought and installed a Spikes.
    Long story short:

    MPI - Magnetic Particle Inspection Process of inspecting the barrels/bolts for defects that might shorten the lifespan of the part

    HPT - High Pressure Test. Use of an M197 test cartridge (or equivalent) to test bolts/barrels at 70K PSI.

    Shot peened - use of small pieces of "shot" to relieve the stress on the surface of a metal.

    Also, proper spec materials like use of Carpenter 158 on the bolts, 4150 CMV barrel steel or FN proprietary "Machine Gun Steel." Stainless steel barrels, depending on the type and manufacturer, can be good to go. A search of the manufacturer on this site will probably turn up some info.

    Quality parts will use fully MPI and (most of the time) HPT barrels and bolts. Some companies forgo the HPT on their bolts (Noveske for example) and there is some debate as to whether it is necessary as it could shorten the lifespan of the bolt. Not going to take a side one way or the other as that's a different discussion, different time.

    Anyway, sometimes PSA lists uppers and BCGs without listing whether or not the bolts are properly inspected and/or tested. Such as this one. While it is made of the proper materials, there really isn't a way of knowing if the bolts are MPI/HPT or not. But they also have ones with the proper testing like this one which details the process.

    And other times, you'll see something like 8620 used like here which is not the official "mil-spec" steel that is supposed to be used and also note the listing does not include any inspection process.

    Barrels used by PSA are mostly FN manufactured varying from 4150 CMV steel to CHF "Machine Gun" steel. Many, if not most are listed as having MPI and HPT done so you are generally safe with PSA. But from time to time you get something like this listed which does not specify.

    So as stated before, just check the specs on what you are picking up. PSA has an industry rep here on this board and they are pretty active over on Arfcom as well for specific questions about their products. They are generally pretty good about answering questions about the specs.

    Also, here's a few other threads to check out:

    https://www.m4carbine.net/showthread.php?t=7355

    https://www.m4carbine.net/showthread.php?t=56063

    https://www.m4carbine.net/showthread.php?t=7009

    https://www.m4carbine.net/showthread.php?t=50559
    Experience is a cruel teacher, gives the exam first and then the lesson.

  5. #25
    Join Date
    Apr 2011
    Location
    Midwest
    Posts
    2,842
    Feedback Score
    18 (100%)
    Quote Originally Posted by gcp View Post
    So there appears to be an AR manufacturers chart somewhere that we all must worship? Typical of the "follower" mentality crowd....pun intended.
    I wouldn't go down this road...

    Quote Originally Posted by gcp View Post
    Grand, can you please elaborate? What is MPI/HPT?
    ...until you're read up on, and understand, stuff like this.
    Last edited by munch520; 07-20-13 at 08:01.

  6. #26
    Join Date
    Apr 2010
    Posts
    69
    Feedback Score
    0
    munch, I am familiar, do understand, and speced out my upper/lower/BCG for MPI/HPT/shot pinned.....before purchase. Too early in the morning and I didn't make the abbreviations connection. As an engineer I very much appreciate well thought out specs/charts and fully comprehend their purpose in life, as long as they are properly understood and utilized by the user.
    Last edited by gcp; 07-20-13 at 08:15.

  7. #27
    Join Date
    Apr 2010
    Posts
    69
    Feedback Score
    0
    Excellent rifle both in performance and accuracy, I am impressed, it shot accurately even my 62gr tracer reloads. More to come this evening, just wanted to share first impressions with you, near real time. My trigger needs more work......



    Last edited by gcp; 07-20-13 at 13:02.

  8. #28
    Join Date
    Apr 2010
    Posts
    69
    Feedback Score
    0
    This Palmetto appears to be a keeper!

    100 yards with my Zmax reloads:
    Last edited by gcp; 07-20-13 at 15:37.

  9. #29
    Join Date
    Apr 2012
    Location
    Albany, Ky
    Posts
    331
    Feedback Score
    0
    I would think twice about polishing the trigger. Once you get through the thin surface hardening it will begin to wear fast, to the point of being unsafe over enough time. If a lighter, smoother trigger is needed I would save up for a Giessele trigger. It's your gun though, just my 2 cents.
    As far as chart worshipers go, you would do well to familiarize yourself with it, couldn't hurt. Looks like a successful build, congratulations.
    Frog Lube Fanboy BCM Koolaid Drinker
    olds442tyguy: I prefer buying American not because of the cost, but because of the integrity. I'd rather send some greedy American guy a couple extra bucks than pay a couple bucks for an inferior product that's likely made from recycled condoms.

  10. #30
    Join Date
    Jan 2008
    Location
    AZ-Waging jihad against crappy AR's.
    Posts
    24,902
    Feedback Score
    104 (100%)
    Please refrain from making silly uninformed comments that will embarrass you later.

    Quote Originally Posted by gcp View Post
    Absolutely nothing broken on my rifles but I do resemble an "unfortunate soul" now and then

    Air, it's a 30mm 6x24 Osprey scope and while decent enough I'll probably install one of my Super snipers on the rifle if it proves accurate enough while shooting it for the first time today. Also, I installed an old red dot Bushnell scope I had laying around for quick acquisition, it works well because it's canted to the left of center thus allowing left eye aim and/or right eye on the larger scope, if bot eyes remain open. I am hopeful that I'll be able to zero it to the right enough to appropriately shift POA/POI.

    Vegas, why goofy look? I liked the purposeful, embedded larger trigger guard, sling attachment, and the shape of the Stark grip that's why I bought & installed it. Only thing different I'd do with them while manufacturing is to rubberize them more.

    I also polished the trigger group to drop it from an 8lb to a now very crisp 5.5-6lb trigger pull.

    So there appears to be an AR manufacturers chart somewhere that we all must worship? Typical of the "follower" mentality crowd....pun intended.

    A few more pics from this morning:





    Owner/Instructor at Semper Paratus Arms

    Facebook: https://www.facebook.com/SemperParatusArms/

    Semper Paratus Arms AR15 Armorer Course http://www.semperparatusarms.com/cou...-registration/

    M4C Misc. Training and Course Announcements- http://www.m4carbine.net/forumdisplay.php?f=141

    Master Armorer/R&D at SIONICS Weapon Systems- http://sionicsweaponsystems.com

Page 3 of 5 FirstFirst 12345 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
  •