Process of dialing in a barrel though the head stock - Page 2
Close
Login to Your Account
Page 2 of 2 FirstFirst 12
Results 21 to 30 of 30
  1. #21
    Join Date
    Dec 2017
    Country
    UNITED STATES
    State/Province
    Idaho
    Posts
    361
    Post Thanks / Like
    Likes (Given)
    104
    Likes (Received)
    83

    Default

    Misfires would make me question headspace. You anyone else to check your work? Extra set of eyes always helps.

  2. Likes Grizzlypeg, Butch Lambert liked this post
  3. #22
    Join Date
    Mar 2006
    Country
    UNITED STATES
    State/Province
    New Jersey
    Posts
    1,082
    Post Thanks / Like
    Likes (Given)
    13
    Likes (Received)
    295

    Default

    Firing Pin Protrusion on a .223 Rem (5.56mm NATO) is supposed to be .030" to .039". Firing Pin indent in a SAMMI copper is supposed to be .020" to .025". This is the standard for DOD and NATO ammo lot acceptance testing.

  4. Likes Grizzlypeg, Tozguy liked this post
  5. #23
    Join Date
    Aug 2012
    Location
    Canada
    Posts
    155
    Post Thanks / Like
    Likes (Given)
    91
    Likes (Received)
    22

    Default

    Fired 40 rounds of Hornady target ammo this weekend, no misfires. Fired a few rounds of Remington 55 grain, no misfires. Shot 20 rounds of my hand loads, no misfires. Also shot some Federal 62 gain with no problem. It seems it only a problem with this Winchester white box 55 grain ammo. Shoots like crap in any event.

    I will measure firing pin protrusion, as soon as I figure out a method. It's good to learn about this potential issue. I can make a protrusion gauge like I saw in a Midway video. That will be a good little project.

    I don't believe head space is my problem. The bolt won't close on a go gauge that has a layer of scotch tape over the base. It closes with slight resistance on my hand loads. Factory ammo (Hornady, Remington and Federal) fits fine and shoots fine, its only that bulk Winchester that is a problem with ignition. Roughly 1/5 don't go off, despite having what appear to be proper firing pin indents.

  6. #24
    Join Date
    Sep 2018
    Location
    Posts
    44
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    18

    Default

    Headspace has two components, the length of the chamber and the length of the ammo. I work at an indoor range and I have seen a lot of problems with white box, including case length. Feed the gun quality ammo and you'll have fewer problems.

    Sent from my Pixel 2 using Tapatalk

  7. Likes Grizzlypeg, Tozguy liked this post
  8. #25
    Join Date
    Aug 2012
    Location
    Canada
    Posts
    155
    Post Thanks / Like
    Likes (Given)
    91
    Likes (Received)
    22

    Default

    I am fighting to shoot 5 shot groups that come in at 1/2" at 100 yards or less. I am finding it very difficult as my skills just aren't there to shoot better than 1/2". Some groups come in at less than 1/2", some times 5 shots and just 2 holes, but any slight change in the way I apply any forces to the gun will throw that off. No doubt you know what I am talking about. I am clearly no bench rest pro. It's actually nerve wracking as I have no excuses and its my slightest error that shows up. The Winchester white box on the other hand shoots 1 1/2" groups. It's only suitable for ringing a gong, or getting a scope close before you switch to better ammo IMO. It's something cheap to shoot through my AR. I will have to shoot some with it and see if it exhibits the same problem.

  9. #26
    Join Date
    May 2013
    Location
    Quebec Canada
    Posts
    108
    Post Thanks / Like
    Likes (Given)
    236
    Likes (Received)
    20

    Default

    Grizzly, about your shooting ability you have company. Sometimes I will ask another shooter to do the trigger work. My daughters usually show me up some at the range.

    Re firing pin protrusion Milgunsmith has provided the numbers above. I had misfires with some factory ammo on a 30-06. Reloads shot well because headspace was minimal and primer depth was also tightly controlled. I had done some work on the bolt and had set the firing pin protrusion too short. After resetting it to maximum the misfires went away.

    Please let us know what you find.

  10. #27
    Join Date
    Mar 2006
    Country
    UNITED STATES
    State/Province
    New Jersey
    Posts
    1,082
    Post Thanks / Like
    Likes (Given)
    13
    Likes (Received)
    295

    Default

    By the way, those numbers work for most Small rifle primers. When you change to Large rifle primers , like .308, .30-06, etc, the protrusion is .060" to .068" and an indent of .020" to .025". In pistol primers, .38, 9mm, .45, it is still .060" to .068" protrusion, but only .011" to .015" indent. The .50BMG primer jumps to .074" to .082" protrusion and .020" to .025" indent. The M1 carbine uses a small rifle primer,with .060" to .068" protrusion and a .011" to .015" indent the same as a pistol.

  11. Likes Grizzlypeg, Tozguy liked this post
  12. #28
    Join Date
    Jan 2009
    Country
    UNITED STATES
    State/Province
    Georgia
    Posts
    68
    Post Thanks / Like
    Likes (Given)
    6
    Likes (Received)
    6

    Default

    A little late to the game here, but I'm definitely in the "dial it precise" camp. It's worked well enough to make a living for the past 9 years advertising a 3/8" MOA guarantee with quality box ammo. I see fewer than 1 in 200 barrel jobs fail to meet that guarantee. I didn't learn to build rifles that way at first, but I do now and I won't share any advice that I haven't seen improve my work first-hand. I started my career as a tech-school-taught manual and CNC machinist, but my first full-time job was in a custom rifle shop.

    I prefer PTG range rods and a pair of Interapid 312B-3 (.0001) indicators on Noga holders. The first barrel I ever dialed in this way took me over an hour. Now I can zero the needles in around 5 minutes. I also dial the muzzle end in that same way. I do it at the breech to minimize the need for reamer holder float (check your chamber run-out after reaming for some enlightening information). I do it at the muzzle end to achieve a concentric and perpendicular crown. The muzzle also sees a reduction in impact shift with muzzle devices like brakes and suppressors using this method.

    The indicator location at the breech end (closest to the headstock/Gritters rod furthest in) is most directly influenced by adjustments made at the chuck (front of the spindle). The indicator location at the end of the rod (furthest from the breech/Gritters rod out) is most directly influenced by the spider at the rear of the spindle. 2 indicators gives you more than twice the information. You not only see run-out, but you where the run-out is, and the way the two needles interact can influence your adjustment procedure heavily. Take into consideration where your adjustment fulcrum is depending on which screws you turn. If both points in the bore show run-out in the same direction, you get to take away run-out in both by adjusting at the chuck, because the barrel pivots at the rear of the spindle and the indicator points are nearly equal in length. If this doesn't make sense let me know. It's been a long day, and I'm only fairly certain I am typing in English.

    As far as the misfires go, pull your un-fired Win White Box out and stand the rounds on a flat smooth surface. If you have any wobbly rounds, they have partially-seated primers and are turning some ignition energy from the firing pin into primer-seating energy, causing ignition failure. Remember the primer face has to not only deform, it has to reach the anvil inside to fire.
    Last edited by jasonixo; 10-10-2019 at 09:19 PM. Reason: Clarification

  13. Likes Grizzlypeg liked this post
  14. #29
    Join Date
    Oct 2002
    Location
    Poetry Texas USA
    Posts
    1,755
    Post Thanks / Like
    Likes (Given)
    314
    Likes (Received)
    213

    Default

    Take a piece of barrel and run your reamer into it. Put a round of ammo into it and measure it with your calipers or mics. Compare that reading to the "bad" ammo. If it is the only ammo giving you problems, the brass has to be shorter from base to shoulder. Don't compare sized ammo.
    I hope you understand. It appears that the "bad" ammo is short or under length on headspace.

  15. Likes Grizzlypeg liked this post
  16. #30
    Join Date
    Nov 2004
    Location
    RC, CA
    Posts
    1,967
    Post Thanks / Like
    Likes (Given)
    211
    Likes (Received)
    371

    Default

    If you're struggling to shoot sub 1/2" groups, and notice that every little pressure you put on the rifle makes a difference ...

    The rifle is good. If it wasn't, your little errors wouldn't be noticeable.

    It's also a 223. There's a limit to what its capable of. I used to see a BR guy at the range regularly. And I saw a lot of ragged hole targets from his PPC. He showed up with a full on BR rifle in 223. Just to see what it was capable of.

    '3's' was what he decided. This was a real 223, no tight neck, no turned 'zero' clearance necks, etc. It shot under 5/8" with south African ball, fwiw.


Tags for this Thread

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
  •