Hornady Taper Crimp Die Instructions

[Keesey]

Loading pics is easy on my iPad



So if these aren't right anyone got the right way step by step

[pitted bore]

Keesey-
Step-by-step could be a book. {The following list is sort of like instructions on how to drive: 1) Get in car. 2) Start car. 3) Put car in gear. 4) Steer to where you want to go. 5) Stop car.}

A) Resize as usual. The instruction leaflet is OK.

B) Expand case mouth. Instruction leaflet is OK. When it states "just enough to seat a bullet", it isn't kidding about the "just enough". Depending on bullet to be seated and case history, it's possible to reload without expanding. I've got a small collection of accordioned cases to show that expanding can be necessary.

C) Seat bullet. The instruction leaflet directions for "Seating without a crimp" should be followed.

D) Taper crimp. The taper crimp die should be set very high in the press to start. Insert the case with the bullet into the shell holder, and lower the handle fully, so the ram is at maximum extension. Screw the die down until it just contacts the case. Then raise the handle (lower the case), and screw the taper crimp die down about 1/8 turn. Lower the handle (pushing bullet up into the die). Raise the handle which withdraws the bullet from the die.

Using calipers, measure the diameter of the case at the mouth. If it's more than 0.476", then screw the die into the press a small bit further (1/8 of a turn), and repeat the process.

If the diameter is less than 0.476 or .475, then you have overcrimped the case around the bullet. It it passes the "thunk" test, it can still be shot, but you've probably distorted the bullet, so accuracy won't be the best. If it doesn't pass the thunk test, disassemble the cartridge and start over.

"Thunk Test" (wildcatter's name) -- a rough and ready test to determine whether you have under- or over-crimped the case with a taper crimp. Make the rifle and area safe so that an oopsie resulting in firing a round is impossible. Drop one of your reloads into the chamber. It should make a "thunk" when the mouth of the bullet contacts the headspace ridge in the chamber. If it makes a non-thunk sort of sound, then the mouth of the cartridge may be going too far into the chamber. Or the round may be wedging in the chamber before the mouth of the case makes contact with the headspacing ridge. You can practice listening for the thunk with a factory round. Your reloads should make the same sound when they encounter the headspacing ridge.

Feel free to ask more questions. The group is dedicated to helping make good 450B reloads. They can also fill in the gaps in the above.
--Bob

[Keesey]

Well I figured that much by looking at the die set not much different then my others but couldn't find any measurements as far as the taper goes.

Also thought from all the talk about the die that there was some special thing that needed to be set up. I guess if you have never used a taper crimp I could see it being overwhelming but still a manageable task.

[wildcatter]

Well I figured that much by looking at the die set not much different then my others but couldn't find any measurements as far as the taper goes.

Also thought from all the talk about the die that there was some special thing that needed to be set up. I guess if you have never used a taper crimp I could see it being overwhelming but still a manageable task.

Shore-Nuff, just do what you do for all of your rimless straight cases, 45acp/9mm/380, etc..

..t

[Jim in Houston]

PB is right on with his instructions, with the following comments:

I have never had to use the expander die (several hundred rounds reloaded) and have never damaged a case trying to seat the bullet. THere is a thread here somewhere about expanding and crimping several time having the potential to weaken the case mouth.

I have crimped to .475 with no problems, but .476 seems to work best. Note that as your case lengths may vary slightly, you will have some variation in final crimp diameter, so if you set up for .476 and have not picked the longest case to set the die, you may get a smaller crimp with a longer case. There is also a thread (somewhere), where someone tried some extreme crimping and had not problems down to something, which was improbably narrow. But no guarantees, of course.

[Keesey]

Well my Dad got me all confused.
He is telling me the seating die is also the crimp die
I am thinking the die that is just a taper to it is the crimp die because I ran a case all the way in it and the results were not good for my brass. Way undersized the case .

Just trying to figure it out due to me going to the range today with rounds we loaded last night and not being happy with the results

[wildcatter]

Keesey-
Step-by-step could be a book. {The following list is sort of like instructions on how to drive: 1) Get in car. 2) Start car. 3) Put car in gear. 4) Steer to where you want to go. 5) Stop car.}

A) Resize as usual. The instruction leaflet is OK.

B) Expand case mouth. Instruction leaflet is OK. When it states "just enough to seat a bullet", it isn't kidding about the "just enough". Depending on bullet to be seated and case history, it's possible to reload without expanding. I've got a small collection of accordioned cases to show that expanding can be necessary.

C) Seat bullet. The instruction leaflet directions for "Seating without a crimp" should be followed.

D) Taper crimp. The taper crimp die should be set very high in the press to start. Insert the case with the bullet into the shell holder, and lower the handle fully, so the ram is at maximum extension. Screw the die down until it just contacts the case. Then raise the handle (lower the case), and screw the taper crimp die down about 1/8 turn. Lower the handle (pushing bullet up into the die). Raise the handle which withdraws the bullet from the die.

Using calipers, measure the diameter of the case at the mouth. If it's more than 0.476", then screw the die into the press a small bit further (1/8 of a turn), and repeat the process.

If the diameter is less than 0.476 or .475, then you have overcrimped the case around the bullet. It it passes the "thunk" test, it can still be shot, but you've probably distorted the bullet, so accuracy won't be the best. If it doesn't pass the thunk test, disassemble the cartridge and start over.

"Thunk Test" (wildcatter's name) -- a rough and ready test to determine whether you have under- or over-crimped the case with a taper crimp. Make the rifle and area safe so that an oopsie resulting in firing a round is impossible. Drop one of your reloads into the chamber. It should make a "thunk" when the mouth of the bullet contacts the headspace ridge in the chamber. If it makes a non-thunk sort of sound, then the mouth of the cartridge may be going too far into the chamber. Or the round may be wedging in the chamber before the mouth of the case makes contact with the headspacing ridge. You can practice listening for the thunk with a factory round. Your reloads should make the same sound when they encounter the headspacing ridge.

Feel free to ask more questions. The group is dedicated to helping make good 450B reloads. They can also fill in the gaps in the above.
--Bob

Hey Bad-Bob, can you pat your head and rub your tummy??

About that Oopsie, I have detonated cartridges that weren't supported at the base and the worst that happens is a slight pop, the bullet stays put and the case flies, say 5 or so feet. However, after saying that, don't do anything stupid and follow normal safety procedures..

..t

Well my Dad got me all confused.
He is telling me the seating die is also the crimp die
I am thinking the die that is just a taper to it is the crimp die because I ran a case all the way in it and the results were not good for my brass. Way undersized the case .

Just trying to figure it out due to me going to the range today with rounds we loaded last night and not being happy with the results

He's right, but most of us do the crimping as a separate step, for fear of bad things happening..

..t

[Hoot]

Good directions Bob!

A few years ago, I had identified several cases who's length had shrunk beyond what I was comfortable with reloading again. For me, that is when it drops below 1.670. I won't even load them with old, pulled bullets for the purpose of bore fouling. I decided to try an experiment with the taper crimp. I took an old bullet that had been pulled for whatever reason and since I don't reuse them due to diameter reduction, I taper crimped it down in .005" increments well below acceptable practice to see when it would stop thunking. I gave up with the mouth at .460 and at that point it was still thunking sharply. As you would guess, the bullet was starting to look like an hour glass. So the question WRT taper crimping is, At what point does the bearing surface of the bullet get distorted to the point of negatively impacting accuracy. Might make for an interesting range experiment, come comfortable shooting weather up here in about 4 months.

For smooth walled .452 bullets, I taper to .476
For smooth walled .451 bullets, I taper to .475
For smooth walled .450 bullets and yes, some manufacturer's QC can be poor at times, I taper to .474

For cannelured .452 bullets, where I seat to almost bury the cantelure, I taper to .475
For cannelured .451 bullets, where I seat to almost bury the cantelure, I taper to .474

For all copper bullets with deep driving band grooves, I have tapered as low as .473. This is one to be careful with as even though the grooves go deeper than any cannelured you're likely to encounter, that doesn't mean you should go down too deep with the taper crimp as the grooves have sharp shoulders and the brass will hang on to that shoulder so much as to cause too much retention and risk dangerous pressure.

Everyone has their spin on this and that's mine.

An important issue is the impact that case length variation has upon the amount of retention yielded by the taper crimp upon the bullet. A taper crimp die with it's depth set to provide .476 on a case that has shrunk to say 1.680 (3rd fired and beyond in my loose chamber) will exhibit a lot more retention when applied to a case that is say 1.695. The die has a continuously narrowing taper the further in you go. While I have not seen this cause signs of dangerous pressure variations, it does cause wider velocity SD swings than I like to see. If you're using the taper crimp and not sorting your cases by length, you're missing an important contributor to consistency. I sort mine in .01 steps. IE 1.670-1.680 (foulers), 1.680-1.690 and 1.690-1.70. I can not provide empirical evidence that those steps are the significant points, they're just easy to remember

Lastly, When you measure your fired and resized case lengths, you will see the length vary when you rotate the case in the caliper jaws. IE, they don't shrink in length the same amount all the way around. I'm not sure if that is relative to the inside vs the outside facing part of the extraction or up vs down. It could be a function of wall thickness variation or chamber concentricity. Just never pursued it. Anyway, pick a convention of measuring at the longest point or shortest, whichever you choose, but measure them the same way each time you re-sort. I use the longest point.

This caliber is amazingly accurate despite case variations that bottleneck caliber accuracy enthusiasts can not allow, so it's not worth tossing and turning over. I try to minimize any variable I can easily correct. Singularly, most don't have a large impact upon consistency, but cumulatively these correctable variations can make the difference between consistent 1" 5-shot, 100 yard groups and consistent 2" groups, or the always maddening 4-shot 1" group with the ruining 5th shot flyer. Also, the error that doesn't amount to a hill of beans in a 50 yd hunting situation can be a wounding shot at 250 yds where environmental factors are also your enemy. Namely crosswind and uphill / downhill trajectory deflection.

Hoot

[Jim in Houston]

Great summary, Hoot!

Thanks for tabulating crimp vs bullet caliber. That is really helpful and clarifies the cannelure issue.

[jerdebson]

Hoot, thanks for the above post. You brought several important points together here so the new or average reloader (me) can make the most out of their reloading experience. Taper crimping and case length go so close together it can not be over emphasized. Also doing any reloading operation the same every time is essential to uniform/accurate reloading, be it measuring cases to the way you operate the press. The same speed, force on all operations will make a great deal of difference, as you mention above. Uniformity is the key word in reloading.

I use to think people reloaded to make better ammo than factory, I have since realized it is difficult to better factory ammo but it is possible to do so sometimes with careful reloading. The thing I believe that makes the difference is you can taylor your loads to your gun.