Page 2 of 12 FirstFirst 1234 ... LastLast
Results 11 to 20 of 118

Thread: Weird cycling issue... thoughts?

  1. #11
    Join Date
    Dec 2015
    Posts
    539
    Feedback Score
    1 (100%)
    Quote Originally Posted by MistWolf View Post
    Have you performed a lockback check?
    I'm not entirely sure what you mean, but if you mean checking to see whether the bolt locks back on the last round fired, yes I have previously. It's how I developed my handload. I've learned that out of all my rifles and "pistols" the MK18 is the only one that's picky about ammo. All the other ARs I load for lock back on light .223 loads even in cold weather, but for the 10.3" with 0.070" gas port I need ammo loaded near or at the top of the published charge weights for the bolt to stay open at colder temps.

    However, the issue I had this past weekend was only with manual cycling of the action. A couple rounds were reluctant to eject manually, but it wasn't every time. I wouldn't even go so far as to say they were stuck; I mortared the gun mainly to prevent pulling back on the CH at an angle. The actual mortaring was quite light. I'm not sure if those particular rounds would've cycled with live fire, but my educated guess is they would have since I had no issues during live fire throughout the day.

    I suppose I could've fired those rounds to see, but I didn't want to risk putting them back into the gun until I double checked them on the case gauge again.

  2. #12
    Join Date
    Sep 2007
    Location
    AZ
    Posts
    32,832
    Feedback Score
    14 (100%)
    Without annealing every piece of brass, you WILL get variations in shoulder bump. There's simply differing amounts of "spring back". Now if the round chambered, the bolt could have bumped that shoulder back enough that it checks out in your chamber gauge. You want your die set so that it's averaging in the middle of the min/max headspace. Too little sizing, and you get sticking rounds. Too much sizing/bump, and you'll get separations.

    Could just be a chamber on the tighter side too that's playing a role in this.
    "What would a $2,000 Geissele Super Duty do that a $500 PSA door buster on Black Friday couldn't do?" - Stopsign32v

  3. #13
    Join Date
    Dec 2015
    Posts
    539
    Feedback Score
    1 (100%)
    Quote Originally Posted by markm View Post
    Without annealing every piece of brass, you WILL get variations in shoulder bump. There's simply differing amounts of "spring back". Now if the round chambered, the bolt could have bumped that shoulder back enough that it checks out in your chamber gauge. You want your die set so that it's averaging in the middle of the min/max headspace. Too little sizing, and you get sticking rounds. Too much sizing/bump, and you'll get separations.

    Could just be a chamber on the tighter side too that's playing a role in this.
    I hadn't thought of that. I currently don't have an annealer, but it's in my future plans.

    Would it matter that it passed a .223 chamber gauge and the chamber is 5.56?

  4. #14
    Join Date
    Apr 2021
    Posts
    1,202
    Feedback Score
    0
    Quote Originally Posted by MWAG19919 View Post
    I hadn't thought of that. I currently don't have an annealer, but it's in my future plans.

    Would it matter that it passed a .223 chamber gauge and the chamber is 5.56?
    An annealer is one of the best investments I’ve ever made.


    Sent from my iPhone using Tapatalk

  5. #15
    Join Date
    Sep 2007
    Location
    AZ
    Posts
    32,832
    Feedback Score
    14 (100%)
    Quote Originally Posted by MWAG19919 View Post
    I hadn't thought of that. I currently don't have an annealer, but it's in my future plans.
    I shoot too much .223 to anneal by hand like I do on bolt gun ammo. I don't have the live round extraction issues that you're experiencing. The Giraud annealing machine would be sweet, but I'd have to have more issues with .223 to justify the expense.

    Would it matter that it passed a .223 chamber gauge and the chamber is 5.56?
    Shouldn't be any difference in what the gauge measures for shoulder bump.
    "What would a $2,000 Geissele Super Duty do that a $500 PSA door buster on Black Friday couldn't do?" - Stopsign32v

  6. #16
    Join Date
    Apr 2021
    Posts
    1,202
    Feedback Score
    0
    Quote Originally Posted by markm View Post
    I shoot too much .223 to anneal by hand like I do on bolt gun ammo. I don't have the live round extraction issues that you're experiencing. The Giraud annealing machine would be sweet, but I'd have to have more issues with .223 to justify the expense.



    Shouldn't be any difference in what the gauge measures for shoulder bump.
    Seems to me that the Bench-source is the way to go for bulk.


    Sent from my iPhone using Tapatalk

  7. #17
    Join Date
    Sep 2007
    Location
    AZ
    Posts
    32,832
    Feedback Score
    14 (100%)
    Quote Originally Posted by mRad View Post
    Seems to me that the Bench-source is the way to go for bulk.
    Maybe. I'm not too familiar with the available options.
    "What would a $2,000 Geissele Super Duty do that a $500 PSA door buster on Black Friday couldn't do?" - Stopsign32v

  8. #18
    Join Date
    Oct 2006
    Location
    Midland, Georgia
    Posts
    2,058
    Feedback Score
    6 (100%)
    Quote Originally Posted by MWAG19919 View Post
    ... when I had to eject a live round from the chamber it was stuck in there pretty tightly. It wasn’t every single time, but the three times it occurred I had to lightly mortar the gun. I can’t quantify the force but it was barely more than the weight of the gun.

    ... a handload of mine (62 gr FMJ, LC brass). Every single round passed a .223 chamber gauge as soon as it came off the press, and the 2 live rounds I recovered passed the gauge a second time (I could not locate the third round).

    The upper is a factory stripped DD MK18 upper with a Toolcraft NIB BCG. I’m not sure if it matters, but the buffer is an A5H0 with a standard rifle spring (I’m pretty sure it’s a BCM spring but it could be Vltor too, can’t remember).
    What drop-in gage are you using? Typically they tell you three things: is the shoulder pushed back far enough, and is the case too short or too long, requiring trimming?

    The JP and Sheridan gages are the only factory ones that will tell you if you're sizing enough for cartridges to freely drop into the chamber. As mentioned, the chamber is your ultimate case gage, and a round dropped in should also fall freely when you point the muzzle up.

    Dillon sizing dies are NOT small-base -- they don't size down far enough because of 550 shell plate thickness and contact with the heads of the brass buttons. Use your micrometer and check how swollen your cases are about a quarter-inch above the case head. If you're using range pick-up brass (or cases once-fired from a GI chamber) and your DD chamber is tighter then you'll need a small-base die (or size with the Dillon dies on a single-stage press).

  9. #19
    Join Date
    Jun 2020
    Posts
    2,193
    Feedback Score
    0
    Quote Originally Posted by MWAG19919 View Post
    Thoughts? I always store the rifle muzzle down and lube it with SLIP2000, so I’m wondering if some lube ran off the BCG into the chamber and gummed it up just enough to make manual extraction difficult. Idk if that’s even a thing, so I thought I’d run it by you gents.

    Could it be the BCG? Ik NIB has fallen out of favor due to wear patterns but this one only has a little over 1k rounds through it.
    The NiB is not your problem. I do not personally go as far as this particular 'internet expert' but he lubes the holy living crap out of his and claims it is just fine:



    (Not suggesting you or anyone lube your BCG like sotar dude does)
    Last edited by DG23; 05-12-21 at 19:19. Reason: spelling skill suck

  10. #20
    Join Date
    May 2012
    Posts
    183
    Feedback Score
    0
    Quote Originally Posted by DG23 View Post
    The NiB is not your problem. I do not personally go as for as this particular 'internet expert' but he lubes the holy living crap out of his and claims it is just fine:



    (Not suggesting you or anyone lube your BCG like sotar dude does)
    Do you have a spare nitride BCG that you can use instead just to see? I always keep a spare BCG just in case situation when I go to the range.

    I have NiB on one AR but it only has about 600 rounds through it. I bought it from Palmetto State Armory a few years back. For my spare BCG I have Toolcraft BCG and my main AR has BCM parkerized BCG in it. I have only had to replace the gas rings on BCM BCG.

Page 2 of 12 FirstFirst 1234 ... 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
  •