Full Answer
Is it possible to over crimp a bullet?
Few bullets designed for autos have cannelures, limiting the amount (and type) of crimp that may be applied. On any bullet, if the crimp being applied is heavy enough to cause any visible deformation, you are over crimping!
What happens if you don't crimp your rifle?
The more cartridges stuffed into the chamber, the more the pressure increases. If bullets aren't crimped adequately, a bullet can pop right down into the cartridge case, leaving your rifle crippled because it can't feed a short, sharp-rimmed case out of the magazine and into the chamber.
What happens if you crimp a round too much?
If you crimp too much, you'll get a round that won't chamber or won't shoot accurately. I have a sample that was over-crimped into a jacketed .45 ACP 230-grain roundnose, and when the case couldn't be crimped any more (the hard bullet stopped inward progress) the case then buckled.
What does a taper crimp do to a bullet?
With a taper crimp, nothing is done to try to force the brass into the bullet. Some cartridges, like many revolver calibers, use a roll crimp.
What happens if you over crimp?
If you crimp too much, you'll get a round that won't chamber or won't shoot accurately. I have a sample that was over-crimped into a jacketed . 45 ACP 230-grain roundnose, and when the case couldn't be crimped any more (the hard bullet stopped inward progress) the case then buckled.
What does crimping a bullet do?
A firm taper crimp on ammunition intended for use in an autoloading firearm is intended to do exactly the opposite; to prevent the bullet from being forced deeper into the case during the feeding cycle. It also serves to ensure reliable feeding by eliminating the sharp edge of the case mouth.
When should you crimp a bullet?
And, because of recoil, the bullet needs to be firmly crimped to keep it from moving and thereby altering the length of the cartridge. Finally, as a general rule for any hunting ammunition, I like to crimp the bullet if there is a cannelure in the right place (some bullets have more than one).
Does Lee bullet seating die crimp?
For Bottleneck rifle cartridges, the Lee Seater Die is an easy adjust dead length bullet seating die. This die does not crimp and will require the factory crimp die.
What is the minimum bullet seating depth?
Most competition rifles will shoot best with bullets seated somewhere between jammed 0.020 and jumping 0.020. …
Why do bullets have a cannelure?
In cartridges, the cannelure is a band pressed into the case which helps prevents cartridge setback when the case mouth is properly crimped onto the cannelure. Bullet setback of . 1" can increase pressure beyond safe limits and possibly cause a catastrophic failure.
Do you crimp 308 Winchester?
No need to crimp a 308 as far as I know. I crimp the majority of my revolver reloads, and anything tube fed that will cause a bullet to set back in the case when it's fired, but thats it.... if your going to crimp, do it last....
What is a taper crimp?
5:217:01Basic Reloading: Taper Crimp Die Part 1 - YouTubeYouTubeStart of suggested clipEnd of suggested clipCase. Now what a taper craft does is it applies pressure to a wider area on the case and the bulletMoreCase. Now what a taper craft does is it applies pressure to a wider area on the case and the bullet with.
What is meant by cannelure?
Definition of cannelure 1 : a groove running lengthwise on the surface of a cylinder or column. 2a : a groove around the cylinder of an elongated bullet for small arms to contain a lubricant. b : a groove around a bullet into which the edge of the cartridge case is crimped.
Do you need a crimp die?
We recommend using the Carbide Factory Crimp Die for pistol calibers if you would like to separate the bullet seating and crimping functions, if you have an auto loader type pistol to ensure the rounds chamber and feed properly or if you would like to apply the appropriate type of crimp for your handgun (auto loaders = ...
What does a Lee crimp die look like?
2:1211:34Lee Factory Crimp Dies - The Best Crimp In The Business - YouTubeYouTubeStart of suggested clipEnd of suggested clipWorks is that the round is put into the die by the press and the round comes through and the colletMoreWorks is that the round is put into the die by the press and the round comes through and the collet applies a very uniform crimp when the collet squeezes. The case mouths into the bullet.
What is a factory crimp die?
Lee Factory Crimp Die crimps your bullets in place the same as factory ammo. A collet gently, but firmly squeezes the very end of the case into the crimping groove, exactly the same as factory ammo. Gives a segmented straight crimp, and crimps more firmly than any other tool.
Why do you taper crimp ammunition?
A firm taper crimp on ammunition intended for use in an autoloading firearm is intended to do exactly the opposite; to prevent the bullet from being forced deeper into the case during the feeding cycle. It also serves to ensure reliable feeding by eliminating the sharp edge of the case mouth.
How to seat a bullet without crimping?
This can be easily accomplished in a single stage press by raising the seating die body enough that the case is not crimped at all when the press is at the top of the stroke. Adjust the seating stem to seat the bullet at the proper OAL , and seat your bullets without any crimp.
Why do you crimp a revolver?
Hard-kicking revolvers, for example, require crimping to prevent the bullets from being pulled out of the case under recoil. In extreme cases this may result in the bullets actually protruding out the front of the cylinder, locking it up and effectively rendering the gun useless.
What is a roll crimp?
The roll crimp is the most commonly seen style for revolver cartridges. As the name implies, the roll crimp entails forming a slight radius at the case mouth by pressing it inward against the bullet. Most bullets intended for use in revolver cartridges have a cannelure, or crimping groove impressed into the bearing surface.
What is crimping in a rifle?
Crimping. Crimping is the final reloading operation applied to either rifle or handgun cartridges. Reloading for most straight-wall cases calls for “belling” or expanding the case mouth to accept the bullet. In its most basic form, crimping is simply a “turning in” of the case mouth to remove the flare left by the belling operation.
What happens after a bullet is seated?
After the bullet has been seated, the round should be given a thorough final inspection before packaging. Cartridges having defects such as collapsed case mouths, crushed, high or inverted primers should be safely discarded, or broken down and the salvageable components reused.
Why do you need a slight ledge on a 45 ACP?
Because of the method of headspacing on the case mouth , a slight ledge must be left to provide positive positioning of a chambered round. An example of an improper type of crimp. These .45 ACP cartridges, intended for use in a semi-automatic pistol, have been given a roll crimp.
What is crimping in bullets?
The problem with crimping is that it sounds so logical. The word “crimping” kind of implies the process of locking a bullet in place. We know that a bullet has to be firmly seated in a cartridge. If a bullet is too loose, it can move during recoil or in extreme cases, fall out of the cartridge altogether.
What happens when a bullet moves out of the case?
If a bullet in a magazine or cylinder moves partially out of the cartridge case during recoil, it can jam up the works . In a revolver, that may prevent the cylinder from turning. In a semi-automatic, that cartridge might cause a feeding jam. On the other hand, if a bullet gets pushed farther into the case, it can increase pressures ...
What is taper crimping?
Think of taper crimping as the process of gently squeezing the cartridge case mouth back into its normal position once a bullet is seated. As we discussed earlier in the series, before seating bullets into straight wall cases like 9mm, you need to ever so slightly flare open the cartridge case mouth to make room to start a bullet seating. After the bullet is seated, the taper crimp gently pushes that flare back to original dimension. Taper crimping really does not do much to increase the tension between the case and the bullet. Consider the wooden dowel example we discussed earlier. In fact, too much taper crimp pressure can squash the projectile, loosen brass case neck tension, and make that bullet less secure than before you started.
What type of crimp is used in machine guns?
Cartridges destined for use in machine guns often use this type of crimp. Bottleneck cartridges that use the shoulder for headspace can use taper crimps, roll crimps, or mashed-up roll crimps like the one in the center.
What cartridges use a taper crimp?
Straight wall pistol cartridges like these use the case rims for headspace, so only a taper crimp can be used. Revolver cartridges like .38 Special, .357 Magnum, and .44 Magnum headspace using the rim on the base of the cartridge. That rim is what stops the case from moving farther into the cylinder.
Why do you use roll crimping on a bottleneck?
You can use roll crimping on cartridges that headspace on the rim or shoulder of a bottleneck cartridge case because the cartridge case mouth edge is not relevant to proper headspacing.
What calibers use the edge of the cartridge case mouth?
Straight wall pistol cartridges like 9mm, .40 S&W, and .45 ACP use the edge of the cartridge case mouth to control headspace. If you look in the chamber of a pistol barrel, you’ll see a little ledge.
What does an over crimped bullet tell you?
To no one's surprise, the reloader complained of unreliable function in his pistol. An over-crimped lead or plated bullet tells you it is unhappy by hurling patterns , not groups. For taper crimp, practical shooting reloaders have been doing it long enough to have hard measurements.
What happens if you crimp a shotgun?
See all Photos. You want to do enough but not too much. If you crimp too little, the extra drag of the un-crimped mouth will cause feeding problems. If you crimp too much, you'll get a round that won't chamber or won't shoot accurately.
What is the difference between a roll crimp and a taper crimp?
And to compound it, we have two crimps: roll and taper. Generally speaking, roll crimp goes on revolver rounds, and taper goes on pistol, but taper is so versatile it can work on both. Taper crimp is much more forgiving than roll crimp, but it is also more subtle, so this article will delve into the aspects of taper crimp.
What do we not use crimp for?
Okay, what don't we use crimp for? Bullet security, a job best handled via neck tension. While the crimp does a small part to control set-back and bullet pull, the main work in that area is done by the neck tension. You control these factors by the diameter of the neck expander in your die set.
Does the left hand round have enough taper crimp?
The left-hand round does not have enough taper crimp. The edge can clearly be felt. Center? Way too much, enough to buckle the case. The right one is properly crimped but is set back in the case from firing, indicating incorrect neck tension — something no amount of crimp can fix.
Can you crimp a bullet pull?
A neck that is too large to control set-back or bullet pull cannot be corrected with crimp, no matter how ferociously you crimp the case. All you do is hasten the onset of neck splits. As an aside, you have correct neck tension when you can see the "Coke bottle" effect on your case, once loaded.
What is crimp ammo?
Your crimp is a key part of the handgun ammo equation and can easily even out your velocities and tighten up your group sizes. After all, that’s a huge part of the reason we handload in the first place. A little bit of extra attention to the crimp will go a long way toward producing the best ammunition available.
What is a crimp in a handgun case?
There are, generally, two types of crimps: 1. u0007Roll crimp: Where the mouth of the case is physically rolled into the bullet’s cannelure.
What is a taper crimping die?
A separate crimping die is employed, which will squeeze the case walls tightly against the shank of the bullet.
How to find the proper amount of crimp?
It takes some experimentation — and several ruined cases — to find the proper amount of crimp by adjusting the seating die body up and down until you get it right. Once you do find it, and lock the die body down in the press, you’ll be all set — that is, until you switch bullets.
What is a roll crimp?
A roll crimp is when the mouth of the case is rolled into the bullet's cannelure. A taper crimp is where the sidewalls are squeezed against the bullet to secure things. Roll crimping is used on most magnum revolver loads — those bullets with a cannelure. Taper crimping is preferred for most autoloading pistol cartridges.
