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dnite
Starting Member
USA
2 Posts |
 Posted - Nov 04 2009 : 18:11:07
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NEWBI needs some help. Some one please explain the steps in taper crimping. I am having a problem with 45ACP OAL shortening in the magazine and then not feeding.
Using RCBS dies and press. |
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lightman
Average Member
127 Posts |
Posted - Nov 04 2009 : 21:49:18
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| Dnite,To taper crimp,you have to have a taper crimp die.RCBS and most other companies offer them in a set,or seperately.It should say taper crimp on it someplace.Using it is not much different than using a roll crimp,you set it up the same way.There is no hard and fast rule for how much to crimp.I usually adjust the crimp until I can't push the bullet into the case.Hope this helps. Lightman Oh,and welcome to the Nest! |
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gunslinger
Average Member
181 Posts |
Posted - Nov 04 2009 : 22:12:03
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| 45 ACP rounds headspace on the case mouth because there is no hatband like 38's, 357's 41'and 44's. As you know, you bell the mouth to accept and bullet and to seat it. Next, the case needs to be straightened to remove the bell but not with a roll crimp. You can get a taper crimp die from almost all the die mfgs. The taper crimp is a separate step and is performed after the bullet is seated. As a general rule, if the loading manuel doesn't give an OAL, just seat it deep enough to load it in the magazine and doesn't bind. When you taper crimp, start by screwing the die down until it comes in contact with the belled case and slowly screwing it down until it pinches the bullet with a .002 to .003 pinch. Finally drop the round into the barrel, it should drop in easily. Good Luck |
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ten2six
Senior Member
USA
248 Posts |
Posted - Nov 05 2009 : 13:53:01
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dnite,
In case you don't have the RCBS instructions on taper crimping, here's a link you can go to:
http://www.rcbs.com/downloads/instructions/ReloadingDieInstructions.pdf
You will need to trim brass to uniform length. Find the minimum length and trim the rest to that. That way, once you get the taper die set, it will not bulge cases as gunslinger mentions.
Stay safe...shoot straight. |
"Chances are, when we meet intelligent life forms in outer space, they're going to be descended from predators."
- Michio Kaku |
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dnite
Starting Member
USA
2 Posts |
Posted - Nov 05 2009 : 17:01:22
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Thanks, guys I will try this. Did not realize I needed a seperate taper crimp die for 45 ACP.
dk |
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Evad
Advanced Member
USA
738 Posts |
Posted - Nov 06 2009 : 00:26:08
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Your die should be a taper crimp die for the 45 ACP. My 9mm RCBS dies have the taper crimp.
Dave  |
I never met a gun I didn't like. |
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Winchester 69
Average Member
USA
171 Posts |
Posted - Nov 10 2009 : 02:01:27
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| The crimp is probably integral with the seating die. |
"I know things about pigeons, Lily." - Eastwood |
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steve4102
Advanced Member
USA
811 Posts |
Posted - Nov 10 2009 : 07:19:05
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You do not need a seperate taper crimp die. Your seating die has a crimp feature built in. That said, I prefer to crimp in a seperate step and leave the seating die adjusted for seating only.
A taper crimp is not used to secure the bullet in the 45ACP. It is used to remove the flare. Sounds like you have other neck tension issues. How about a rundown on your dies and how you have them set up?
If your rounds are "shortening" in the mag, that's bad. Depending on the load and cartridge, bullet set back in a handgun load can be dangerous. |
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lightman
Average Member
127 Posts |
Posted - Nov 10 2009 : 21:03:04
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| Dnite,I did'nt word my first post very well,and I hope that I did'nt confuse you!What I meant was that to taper crimp,you have to be sure that you have a taper crimp die.Witk RCBS dies,you probably do have one.You can look on the top of the die,it should say.As someone else said,you will probably have to seat and crimp in seperate steps.Also,as someone else said,if your bullet is that loose you are probable expanding the case mouth too much or your sizing die is not adjusted correctly.I load most of my pistol ammo on a progressive press and I do have a seperate crimp die,but you won't need one on a single stage press.Thanks everybody for straightning me out. Lightman |
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F. Guffey
Senior Member
USA
322 Posts |
Posted - Nov 11 2009 : 08:39:14
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" You can get a taper crimp die from almost all the die mfgs. The taper crimp is a separate step and is performed after the bullet is seated. As a general rule, if the loading manuel doesn't give an OAL, just seat it deep enough to load it in...."
Except for my one set of Dillon dies the crimp die is also the seater die meaning seating and crimping is done simultaneously, the bullet is seated while the case is crimped, for some this is not a good ideal when roll crimping, seems the dynamics of seating is a conflict when crimping, the bullet is moving down while the crimp is being applied, this causes the crimp at the mouth of the case to dig into the bullet, at this point the crimped case digs into the bullet, when this happens the case can bulge if the bullet continues to be seated, so a separate crimping die is not required, seat with a seater die set up as a seater die then raise the seater plug after seating then use the seater die to crimp, roll or tapper, again I have 45 ACPs that like new ammo, I crimp with a full length sizer die, no taper, cases crimped in this manner make the pistol think it is getting the good stuff, getting started, remove the bell with the seater die first, this is not full length sizing only 1/4 to 1/3 of the case is sized, this method improves the appearance of the finished ammo, especially when the loaded rounds, after seating bullets, take on the appearance of a case that looks like it swallowed a bullet.
F. Guffey
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edward5759
Average Member
133 Posts |
Posted - Nov 12 2009 : 10:29:21
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Take you sizing die decapping pin out.
Put a loaded round in your press run the ram up.
Screw the resizing die down to where it just starts to make contact.
Adjust in 1/8 turns until the desired taper is achieved.
This will save you while you wait for a taper die. This is the same thing.
Measure them!
ed |
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emrah
New Member
19 Posts |
Posted - Nov 13 2009 : 20:19:59
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I'm a little unclear on this too. Just WHERE does the crimped edge go? I understand on a bullet with a cannelure, the brass "bends" into the cannelure. On a bullet that has no cannelure, where does brass bend into? Can you only taper crimp if the bullet is seated deep enough for the case mouth to bend inwards into the ogive of the bullet? What if you seat the bullet only deep enough that the case mouth is still on the straight (non-ogive) part of the bullet? Where does the mouth bend into then?
As you can tell, I've only been loading jacketed bullets (I don't flare the mouth before seating it; nice snug fit) and lead bullets with cannelures.
Emrah |
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Evad
Advanced Member
USA
738 Posts |
Posted - Nov 13 2009 : 23:08:05
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A taper crimp justs tapers the case so that the bullet is a tight fit in the brass, the edge just gets pushed to the sides of the bullet, because the case headspaces on the very end of the brass. If you try to roll crimp, you destroy the headspace of the brass. And the case and gun has no headspace point. Hope this helps,
Dave
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I never met a gun I didn't like. |
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emrah
New Member
19 Posts |
Posted - Nov 13 2009 : 23:35:14
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I get the process, I just don't understand how once the brass is flared, a bullet seated, the brass can then be formed back tightly along the edge of the bullet. I guess I'm thinking about it like any other metal. All metal has "spring" to it. If you bend it one way from "straight", then in order to get it "straight" again, the metal must be flexed PAST the original position and have it spring back straight. Does that make sense?
Anyway, that's the part I don't get. If the mouth is flared, then you seat a bullet, how can the brass be bent back enough to be straight again and still have tension to grip the bullet? It can only be pushed back so far; otherwise it would need to crush the body of the bullet in the mouth. So how does it "crimp" tightly enough against the bullet that can't crush?
Emrah |
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Evad
Advanced Member
USA
738 Posts |
Posted - Nov 14 2009 : 01:24:35
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Only the top 32nd inch or so is flared, the taper crimp just pushes it back to approxmately straight. When it is pushed back that is just to make it headspace right, not to hold the bullet tight. The taper crimp squeses the case tight around the bullet under the case mouth.
Dave |
I never met a gun I didn't like. |
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ten2six
Senior Member
USA
248 Posts |
Posted - Nov 14 2009 : 13:53:00
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Emrah,
Most handgun bullet seating dies, and crimp dies for that matter, narrow inside to work the flare back to true, or slightly inward for a crimp. By setting up your die properly, you're working just the brass that needs to be worked. The bullet seating is adjusted with the stem, so that is separate. Where you seat the body of the die determines if you true or crimp. Where you adjust the stem determines the OAL. Even jacketed bullets will take a small crimp.
Without a crimp, the bullet is held merely by the tension of the brass (outside diameter of the bullet minus the inside diameter of the neck before seating).
Stay safe....shoot straight.
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"Chances are, when we meet intelligent life forms in outer space, they're going to be descended from predators."
- Michio Kaku |
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Topic |
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taper crimp
