Welcome to M1911.ORG
The M1911 Pistols Organization Forums Site


John needs your help
Please read this message.


Sponsors Panel
If you intend to buy something from the companies advertising above, or near the bottom of our pages, please use their banners in our sites. Whatever you buy from them, using those banners, gives us a small commission, which helps us keep these sites alive. You still pay the normal price, our commission comes from their profit, so you have nothing to lose, while we have something to gain. Your help is appreciated.
If you want to become a sponsor and see your banner in the above panel, click here to contact us.

Page 1 of 2 12 LastLast
Results 1 to 10 of 20

Thread: Brass Resizing Situation - Step in Diameter

THREAD CLOSED
This is an old thread. You can't post a reply in it. It is left here for historical reasons.Why don't you create a new thread instead?
  1. #1
    Join Date
    1st April 2020
    Location
    Ohio
    Posts
    44
    Posts liked by others
    0

    Brass Resizing Situation - Step in Diameter

    I have been checking all my empty brass against SAAMI specs for length. I am rejecting 10% to 20% undersized depending on the headstamp. The only exception was PMC which had no rejects at all. The other brands checked include: Winchester, WCC, WCC Match, R-P, Federal and mixed nickel plated cases.

    Rejects from R-P and the mixed nickle cases all have a step in the diameter near the case head. I clean the cases before resizing. I am using an RCBS carbide sizing die that gives me .466 diameter.

    Some cases are once fired and others have been loaded a number of times.

    Has anyone else ever experienced this? What is the cause? It makes me think my sizing die is too small but I am unaware that there are size choices available.

    Seems like I've uploaded my photo twice. Rookie mistake.
    Attached Images Attached Images


  2. #2
    Join Date
    2nd October 2006
    Location
    Weeki Wachee, Fl
    Posts
    5,589
    Posts liked by others
    181
    If they aren’t feeding properly in your pistols; a small base sizing die will alleviate the problem. If they feed OK in your pistols, don’t worry about it.

    For as long as I’ve been reloading (over 32 years now), my pistol brass for both 9mm and .45 acp has looked a little “wider” just ahead of the extractor groove, compared to the rest of the case. That said, I’ve never had one that wouldn’t chamber and fire properly.
    "Sights are for the unenlightened."

    Rick

    IDPA Certified Safety Officer

  3. #3
    Join Date
    1st April 2020
    Location
    Ohio
    Posts
    44
    Posts liked by others
    0
    Rick McC, Thanks. I was afraid they had seen too much pressure but now I see they are quite a bit short per SAAMI specs. I just rechecked the set up on my sizing die and it was a bit too deep so I backed that off a bit. And they do feed just fine.

    I also checked the case diameter just above the extractor groove for the R-P cases and got .473 which is the SAAMI reference dimension for the case diameter. I measured a Fedreal case that doesn't do this and the diameter at the same point was .470.
    Last edited by paleojack01; 10th April 2020 at 22:42. Reason: add content


  4. #4
    Join Date
    2nd June 2004
    Location
    Terra
    Posts
    22,286
    Posts liked by others
    906
    Quote Originally Posted by paleojack01 View Post
    Seems like I've uploaded my photo twice. Rookie mistake.
    Fixed. You can fix things like that. "Manage Attachments"
    Hawkmoon
    On a good day, can hit the broad side of a barn ... from the inside

  5. #5
    Join Date
    1st April 2020
    Location
    Ohio
    Posts
    44
    Posts liked by others
    0
    I have make a correction to my last post. The SAAMI case diameter just above the extractor groove is .476 (not .473). So my brass is in spec. Hawkmoon, thanks for fixing the double photo issue.

  6. #6
    Join Date
    25th September 2006
    Location
    South of Lake Superior
    Posts
    14,085
    Posts liked by others
    127
    As I recall, the instruction for my 45 Auto resizing die call for it to be adjusted so the shell holder doesn't quiiiite touch the bottom of the die. Even remember grinding down the top of one shell holder so the cases went up a little farther into the die. Doing so insures the case is given as much of full-length resizing as is possible. But this raises these questions:

    • Is it important for 45 Auto cases to be full-length resized?
    • What happens if they're not full-length resized?
    • Could they get shorter?

    Don't know the answer to any of those. All I know for sure is I've never seen cases like the ones in your photo. And I've been reloading them for <gulp> 55 years. They almost look belted!

    Maybe somebody else has the answers.
    When you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind. [Lord Kelvin]
    Last edited by niemi24s; 11th April 2020 at 20:58.


  7. #7
    Join Date
    1st April 2020
    Location
    Ohio
    Posts
    44
    Posts liked by others
    0
    neimi24s, I agree, they do look belted. My only suspicion now is that the resizing die just takes the diameter down too far - .466 which is much smaller than the SAAMI numbers. This doesn't show up on other headstamps, only R-P and they are larger in diameter near the extraction groove than other headstamps I have but well within SAAMI specs. I'd be interested to know what diameter others here get when resizing and if different than mine, what dies are being used? As I mentioned in another post here, when I seat a bullet, the case mouth diameter expands out to .470 to the depth of bullet seating. Behind that it is .466 so the finished cartridge is bulged at the mouth end slightly.

  8. #8
    Join Date
    2nd October 2006
    Location
    Weeki Wachee, Fl
    Posts
    5,589
    Posts liked by others
    181
    I’ve never seen any casings with that sharp edge at the top of the bulge.

    They can only be coming from two places; either your chamber, or your sizing die.
    "Sights are for the unenlightened."

    Rick

    IDPA Certified Safety Officer

  9. #9
    Join Date
    25th September 2006
    Location
    South of Lake Superior
    Posts
    14,085
    Posts liked by others
    127
    Don't forget that the SAAMI specifications are for loaded commercial ammunition and NOT for reloaded ammunition. Your 0.466" OD as the case comes out of the resizing die matches mine. And while 0.466" is less than the SAAMI spec, that's the OD before the bullet is seated. If your bullet is actually 0.452" OD and your brass is 0.0095" thick, the finished case OD will be about 0.471" (which does meet SAAMI specs) with a step (aka, bulge) at the bottom of the bullet of about 0.0025". Con't worry about the bulge. The bulge is a good thing because it shows that the bullet has stretched out the case during seating and that the case has a good grip on the bullet.

    • Adjust your resizing die so the top of the shell holder is a hair away at the top of the press stroke - just like its instructions probably tell you.
    • Keep on using that brass you rejected as being too short. I suspect they'll probably get back to spec after being loaded, shot and reloaded a few times.
    • Follow RickMcC's lead and carefully examine you chamber and resizing die for the source of that step just ahead of the extraction groove. That step is highly abnormal and is worrisome to me.

    Q: What's the present gap between the top of your shell holder and bottom of the resizing die when the ram is at the top of its stroke?
    When you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind. [Lord Kelvin]
    Last edited by niemi24s; 11th April 2020 at 21:26.


  10. #10
    Join Date
    9th March 2006
    Location
    Grand Rapids, MI
    Posts
    416
    Posts liked by others
    11
    Redding has a write-up on their dual ring sizers. I believe these are available for 45acp. Even if not interested in the alternate sizer it's a good piece of info.

    I've seen similar with carbide sizing, these force the body to the same diameter as the case mouth. As mentioned earlier you might try to not size it quite as far down.

    If it fits into the chamber and case gauge I wouldn't get too concerned, at the same time I don't like it.

    Jim

Page 1 of 2 12 LastLast

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  



Sponsors Panel
If you intend to buy something from Brownells, please use their banners above. Whatever you buy from them, gives us a small commission, which helps us keep these sites alive. You still pay the normal price, our commission comes from their profit, so you have nothing to lose, while we have something to gain. Your help is appreciated.
If you want to become a sponsor and see your banner in the above panel, click here to contact us.

Non-gun-related supporters.
Thank you for visiting our supporters.