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One step crimp/seat

Discussion in 'Handloading and Reloading' started by jr_roosa, Sep 14, 2012.

  1. jr_roosa

    jr_roosa Well-Known Member

    Ok. I fought the good fight. I bought an m die. I twiddled. I tweaked. I tried a couple of different bullets.

    I give up. I still shave lead when I try to seat cast lead in 45acp while trying to get enough taper crimp to get them to fit a case gauge.

    I went back to the two step process and realized its just much easier to run through twice. Every round comes out perfect. No lead shavings. I even apply less crimp now and get a better result.

    I'm going to midway right now to get a couple extra die bodies for seaters so I can leave everything set.

    The m die is awesome for keeping the bullets straight. Glad I got it.

  2. ArchAngelCD

    ArchAngelCD Well-Known Member

    I have been seating and crimping my handgun ammo in 2 steps for years. sure it can be done in 1 step but I like the results I get in separate operations. It's just my preference...

    Funny thing is, when I load 45-70 ammo I load a lead bullet and I seat and crimp with one die without problems... I use a 4 hole turret press for my handgun ammo and a single stage for my rifle ammo so I just don't want to change dies to crimp on the single stage whereas the dies are all set up on the turret press.
  3. cfullgraf

    cfullgraf Well-Known Member

    Lots of folks seat and crimp in the same step.

    I have been doing it separately for decades. One of the reasons I finally bought a progressive a couple years ago was to seat and crimp with one pull of the handle but in different dies.
  4. ColtPythonElite

    ColtPythonElite Well-Known Member

    I have always seated and crimped in one step with no problems.
  5. Sport45

    Sport45 Well-Known Member

    It's easy to seat/crimp in one step if the bullet has a crimp groove and the cases are all the same length. Just make sure the crimp starts after the mouth passes the bottom of the groove and finishes before it hits the top of the groove.
  6. Lost Sheep

    Lost Sheep Well-Known Member

    Sport45 is correct. That is a good way to do it.

    It is also possible to even do a taper crimp die on a bullet without a crimping groove. But the adjusting of the dies is very fine. And the case length must be consistent. Do you measure your case lengths?

    Lost Sheep
  7. jr_roosa

    jr_roosa Well-Known Member

    Oh, totally. I've never had any problem with a roll crimp for revolvers with a crimp groove, or with rifle bullets with a cannelure. No problem with jacketed bullets in .45 ACP either with one-step. It's the taper crimp on the .45 ACP with cast lead bullets that's been driving me batty for months.

    I used to do it in 2 steps before, and then decided that it would be more efficient to do it in one step. I tried all the suggestions that I could find, and I still spend 45 minutes messing with the die every time I load a batch, especially when I change from one bullet to another.

    Well, swing on by next time you're in the neighborhood and show me where I'm screwing up. There's a fridge full of beer right next to the bench for after we figure it out. Even if we don't figure it out, the beer is still there.

  8. jr_roosa

    jr_roosa Well-Known Member

    Nope. If I measure each case then I would lose all of the time I save by combining the two steps. Also, the bulk of my loads are mixed brass/230gr LRN.

    I'm a little more neurotic for my bullseye loads, but not much. I have a new Bullseye gun coming back from the smith next week after almost a year of work, and we'll see if it cares about case length variation at the 50yd line. If it doesn't care, then I won't either.

  9. Sport45

    Sport45 Well-Known Member

    For .45acp I only crimp enough to remove the flare/bell. If you are digging into the bullet you are applying too much crimp. Same goes for 9mm, .40S&W, and any other cartridge that headspaces on the case mouth.

    The revolver bullets I use all have grooves for crimping. If they didn't, I'd seat/crimp in two steps for sure.

    All that said, I normally crimp separately on my 550b anyway since it has the extra die position. When using a single stage or turret (I use mine as single stage) I usually seat/crimp in one step just to avoid pulling the handle again.
  10. GLOOB

    GLOOB Well-Known Member

    ^ Depends on how tight your chamber is. I have done fine one-stepping 9mm and 40SW with cast bullets even with mixed brass. But I'm only just barely crimping the longer cases. (Leaving a bit of flair on the shorter ones).

    Never could do it with my cast 45's. My Glock 21's chamber is just too tight to run without a decent crimp. Well, I never could until I started using MBC 200 gr IDP#4's. .452" diameter bullets with a crimp groove. Love 'em! (Obviously just removing the flare, not roll crimping!)
  11. res7s

    res7s Well-Known Member

    I seat and crimp in two steps with 30-30, 308 Win(with cast bullets), 30-06(with cast bullets), 32 S&W Long, 45 ACP, 44 Mag, and 40 S&W. Everything else I pretty much do it the traditional way. From the looks of things I'm slowly going to two steps myself. That list used to be just one cartridge.

    You gotta' do, what works for you.
  12. Walkalong

    Walkalong Moderator

    Pretty much.
  13. bds

    bds Well-Known Member

    I seat and taper crimp in one step.

    But I really do not apply any "negative" taper crimp - I just return the flare back to flat or add .021" to the diameter of the bullet (so for .451" lead bullets, .472" taper crimp).

    I use the tightest chamber barrel I have as my case gauge. My Sig 1911 chamber is really tight with almost no leade (I need to load 200 gr SWC no longer than 1.245"). Even with such a tight barrel, .472" taper crimped rounds will snuggly fully chamber but won't drop in freely with a "plonk" (Yeah, like my 40S&W Lone Wolf barrels, I even thought about polishing the chamber a bit). This is OK with me as the force of slide returning to battery has fully chambered all of these rounds - This probably produces more consistent chamber pressure build up and may explain why it continues to produce accurate shot groups.

    If you are using less than .471"-.472" taper crimp, using separate two steps for seating and taper crimping will prevent shaving of lead.

    Last edited: Sep 15, 2012
  14. 243winxb

    243winxb Well-Known Member

    Different Die = Different Results.

    Had a RCBS 45 acp seating die that would always shave lead when seating cast lead .452" diameter bullets. The seating stem had to be turned all the way in/down to keep from shaving. Had to use a separate operation/taper crimp die. An adjustment to the die was needed, as the bell was being removed to soon. This is because the die body was too tight/small in front of the taper crimp area. Opening up the inside diameter of the die corrected the problem. If you try adjusting the die, make sure you dont go to deep into the die and remove the taper area. Bell a case mouth a little more than normal. Measure the flare by letting the case hang in a vernier caliper. Slowly pull the case down thru the caliber. Take a reading. Run case into die about 1/3 . Measure again. Keeping doing this to find out if you have a tighter than needed inside diameter.
  15. jr_roosa

    jr_roosa Well-Known Member

    I could get around .475 without shaving anything but that is really snug in my chambers. They seem to like around .473 or less.

    Maybe it's my crimp die. It just seems to crimp too gradually so that there is about 0.100" of scraping in order to get to .472.

    If I bell less, i can't get the bullets to start straight with either the m die or the rcbs expander. The more I expand, the lower I need to put the crimp die to get rid of the bell. And the more lead gets scraped off.

    If the two step didn't make perfect rounds, I might continue the struggle with maybe a new crimp die or something.

    I will still crimp and seat in one step with jacketed rounds. I even have some FMJ coming in the big brown truck. If they're easier to load (one less step) then that makes up for the increased price. Plus they make cleaning easier.


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