Notes about the Lee .45 Taper Crimp Die

[Hoot]

If you have the Hornady 450b sizing dies and feel adventurous, try using it for a taper crimp minus the decapper. I did out of curiosity and it worked great. I was hoping for some kind of epiphany but all it brought to the table was working just a good as the 450b Taper crimp die, but not better. I believe it a gentler angle than the taper crimp die.

Hoot

[Texas Sheepdawg]

Understood. So I need the 45-70 Taper crimp die. But I'm not sure about how to modify it.

[Hoot]

Understood. So I need the 45-70 Taper crimp die. But I'm not sure about how to modify it.

???

[pitted bore]

Understood. So I need the 45-70 Taper crimp die. But I'm not sure about how to modify it.

TSD-
Did you intend to ask about the Lee 45-70 Factory Crimp Die.

Lyman makes a 45-70 taper crimp die. Redding makes a "profile crimp die" for the 45-70, but that die may apply a roll crimp. I lack the necessary experience to see how these could be used in reloading the 450B.

Depending on what you're trying to accomplish with the 450B, a modified Lee 45-70 Factory Crimp Die may or may not be needed. The Hornady Die Set will perform just fine with the bullets recommended by Hornady's data sheets.

At the top of this 450B Reloading Forum, there are two sticky threads about modifications to the Lee 45-70 FCD:

• Lee FCD Mod Step-By-Step w/images
• The "modifying a Lee 45-70 factory crimp die" thread

Perhaps you could elaborate on your question?

--Bob

[Texas Sheepdawg]

I've read over those but I do not have any way to modify the die. I don't have any machinists that I could trust to do it. I have been reading all of the posts on crimping and quite frankly, I am totally lost.

[pitted bore]

I have been reading all of the posts on crimping and quite frankly, I am totally lost.

TSD-
Your being confused is understandable. Discussion of crimping has been continual since the start of the calguns thread. Crimping topics seem to arise for three principal reasons:

First, when novice reloaders ask about the fourth die in the Hornady 450B die set. Hornady thoughlessly failed even to mention the fourth die in their instructions included with the set.

Second, when either novice or experienced reloaders ask about the use of the crimping shoulder built into the Hornady 450B seating die.

Third, when a reloader wishes to experiment with bullets, powder, and cases that fall outside Hornady's lab-tested recommendations.

Crimping is important, because the bullet needs to be held firmly through the shuffle-slam of the chambering cycle. For many of the recommended powders, a firm crimp is needed to ensure a proper powder burn. However, too much crimp can cause headspace problems because the cartridge headspaces on the case mouth, which excess crimping will distort. The balance between too much and not enough crimp is critical, and so it receives considerable attention in the reloading forum.

If one sticks with Hornady dies using the standard drill for 4-die sets of other cartridges, and if one uses the recommended components, then most crimping discussions here can be ignored. Just remember 0.476" for the case mouth OD of finished reloaded rounds.

Does this help?

--Bob

[Texas Sheepdawg]

I'm still scratching my noggin. Since I can't modify a die like what WC and others have done, would the
Lee #90785 be the answer?

[pitted bore]

I'm still scratching my noggin. Since I can't modify a die like what WC and others have done, would the Lee #90785 be the answer?

TSD-

If the question is "How can I crimp a 450B handload using some die other than the Hornady taper crimp die", then Lee #90785 may be an acceptable answer.

In my experience the Lee #90785 works fine; see the first post of this thread. The Lee die will apply a firm taper crimp leaving a case mouth outside diameter of about 0.476".

If you should try it and that is not what you find, please post your results here.

Thanks.

--Bob

[BD1]

The acid test for your crimp is to carefully measure the cartridge over all length of a particular round, then let the bolt strip it off the magazine and chamber it. Then eject it, (unfired), onto something soft and carefully measure the COAL again. If the COAL stays the same after you've tried this on several different rounds, your crimp is doing it's job OK, no matter which die setup you used. If your COAL occasionally changes from chambering a round, then you need more crimp, or a different crimp.

Up until recently, cartridges that headspaced on the case mouth were primarily semi auto handgun, or sub gun rounds; .380, the various 9mms and .45 acp being the most common. IMHO the primary role of the crimp in these rounds was to prevent the bullet from being set back into the case when the bullet nose slammed into the feed ramp on it's way to the barrel. The standard taper crimp does this pretty well. This is a small factor in the .450B, but we also have to keep the bullet from jumping forward when the case comes to an abrupt stop against the chamber mouth after being slammed in there by the bolt. In heavy recoiling straight wall cases, like the .44 mag, .444 Marlin, .454 Casull or .45-70 this bullet jump is typically prevented by a heavy roll crimp into a crimp groove or cannelure. Unfortunately a heavy roll crimp is not practical in a cartridge that headspaces on the case mouth. This need to prevent bullet movement in either direction is why I like the "side" crimp.

BD

[wildcatter]

As per-usual, BD has it down.

The primary use of the Crimp is indeed to keep the bullet from traveling in the case, and nearly as important, is to induce "Bullet Pull", or that hesitation, before the bullet start to move in the case. The longer that period, the better the powder burn. So, we try to keep both of these things in mind when crimping, hence the LeGendre Side Crimp.

But, TEX, brings out an important point about getting a LSC Die made.

Question, do I need to make up a couple of dozen of them an peddle them to those in Tex's shoes? Who'd be interested?..

..t