I finally decided to make the move into reloading and have done quite a bit of research in terms of equipment and other related info. One area I'm still very foggy on is the crimping die and what it does exactly. Does anyone have a good example of what it does and what the benefits are? Thanks!
Newbie question - Crimping Die
- Thread starter delta1679
- Start date
Register to hide this ad
RIKMAN
Member
The crimp die helps to retain the bullet in the case after seating it. There are two types of crimp,"taper" as in a 45acp and "roll" crimp as in 38/44spl bullets with a "cannelure" groove.
RIKMAN
Member
A good piece of advice is to buy and read some good books like "The ABC'S of Reloading" and a reloading manual like "Lymans 49th Ed".
I took it a step further and took an NRA Metallic class.
I took it a step further and took an NRA Metallic class.
You must crimp all cartridges intended to be used in a revolver. The main reason is: upon recoil the unfired bullets want to back out of their cases. They have this tendency because they are obeying one of Newton's laws... "a body at rest wants to remain at rest" etc. When a bullet backs out sufficiently from its case, it renders the revolver USELESS! The cylinder will not rotate because of the bullet(s) protruding from out in front...hitting the sides of the frame as the cylinder rotates. I learned this the hard way...luckily at the range. Reloading is a lot of fun and definitely saves a lot of money, enabling you to shoot more, plus you end learning more about ballistics etc.. Keep doing what you are doing....ask questions and learn from our and your mistakes.
My advice...if you are loading bullets without a crimping groove, still give 'em a little squeeze with the crimping die.
Cap
My advice...if you are loading bullets without a crimping groove, still give 'em a little squeeze with the crimping die.
Cap
Kelly Green
Member
The reason you want to crimp is to increase neck tension. Neck tension will add resistance as the bullet starts its movement out of the case allowing pressure to build and ensuring complete combustion of the powder.
A roll crimp is the most common type of crimp for a revolver cartridge. A semi-auto round normally uses a taper crimp to keep the bullet form being pushed back into the casing. This is the exact opposite of a revolver where an un-crimped bullet may be pulled out of the casing. A crimp will also ensure reliable feeding in a semi-auto.
Buying and reading a couple (or more) reloading manuals is money and time well spent. And, keep asking questions.
A roll crimp is the most common type of crimp for a revolver cartridge. A semi-auto round normally uses a taper crimp to keep the bullet form being pushed back into the casing. This is the exact opposite of a revolver where an un-crimped bullet may be pulled out of the casing. A crimp will also ensure reliable feeding in a semi-auto.
Buying and reading a couple (or more) reloading manuals is money and time well spent. And, keep asking questions.
What a crimp should be is very dependent on the pistol caliber and type of ammo.
Example: 9mm Luger should have almost no crimp, using the taper crimp die mostly to remove the bell you put in for loading.
On the other hand, .357 mag should have a heavy roll crimp in the bullet cannelure to insure consistent ignition of the heavy charges of slow powder.
More crimp is not always good, but if you don't use a crimp die, the remaining bell at the case mouth causes problems.
If the case is not sized correctly, no amount of crimp will hold the bullet on its own. Most of the holding power is friction on the bullet shank, not the crimp.
Example: 9mm Luger should have almost no crimp, using the taper crimp die mostly to remove the bell you put in for loading.
On the other hand, .357 mag should have a heavy roll crimp in the bullet cannelure to insure consistent ignition of the heavy charges of slow powder.
More crimp is not always good, but if you don't use a crimp die, the remaining bell at the case mouth causes problems.
If the case is not sized correctly, no amount of crimp will hold the bullet on its own. Most of the holding power is friction on the bullet shank, not the crimp.
Thank you for the info! I intend to reload .40 S&W for my SW40VE and .380 for my wife's Walther PK380. I'm looking at picking up the Lee turret press. Based on reviews it's a quality product and it fits into my current budget.
I've definitely been learning alot from the posts here and elsewhere on the web. Thanks again.
I've definitely been learning alot from the posts here and elsewhere on the web. Thanks again.
gregintenn
Member
I've always had good luck crimping with my bullet seating die. Others will have differing opinions.
delta,
I don't want to discourage you, but if you're new to reloading, .40 S&W is a sensitive cartridge to reload. First and foremost, because of high pressures, even a small amount of bullet setback can lead to a Ka-Boom for certain bullet/powder combinations. You must have sufficient neck tension to keep the bullet from moving in the case. Second, pay close attention to overall cartridge length - don't go less than the recommendations in the loading manual, ever. You will have many fewer problems if you are a careful reloader.
Buck
I don't want to discourage you, but if you're new to reloading, .40 S&W is a sensitive cartridge to reload. First and foremost, because of high pressures, even a small amount of bullet setback can lead to a Ka-Boom for certain bullet/powder combinations. You must have sufficient neck tension to keep the bullet from moving in the case. Second, pay close attention to overall cartridge length - don't go less than the recommendations in the loading manual, ever. You will have many fewer problems if you are a careful reloader.
Buck
Most of the guys here have been loading long enough that they can tell by smell if a round is correctly seated and sized. Me - not so much. I'm a noob too. I read the manuals and take a ton of measurements.
The Lyman book and others have an explanation of crimp and a diagram of each individual round showing the dimensions of the case at the base and at the mouth. The bare minimum crimp will be reflected by the mouth dimension and you need a decent pair of calipers to measure it. It is my opinion only but I say do not waste your money on a set of plastic calipers from the dollar store or stamped out Chi-com ones from Harbor Freight. At best, they're misleading. At worst, they can be dangerous. You're trying to repeatedly verify measurements in ten thousandths of an inch.
Starrett Dial Calipers can set you back a minimum of $50 and decent digitals are $150 or more. Also consider Mitutoyo Japan. Similar pricing.
In addition, I have case gages in each caliber. These will also give you an indication of whether the round is sized right. Some here use their gun barrel for this.
Just my dos centavos ...
The Lyman book and others have an explanation of crimp and a diagram of each individual round showing the dimensions of the case at the base and at the mouth. The bare minimum crimp will be reflected by the mouth dimension and you need a decent pair of calipers to measure it. It is my opinion only but I say do not waste your money on a set of plastic calipers from the dollar store or stamped out Chi-com ones from Harbor Freight. At best, they're misleading. At worst, they can be dangerous. You're trying to repeatedly verify measurements in ten thousandths of an inch.
Starrett Dial Calipers can set you back a minimum of $50 and decent digitals are $150 or more. Also consider Mitutoyo Japan. Similar pricing.
In addition, I have case gages in each caliber. These will also give you an indication of whether the round is sized right. Some here use their gun barrel for this.
Just my dos centavos ...
Maximumbob54
Member
- Joined
- Oct 2, 2010
- Messages
- 7,202
- Reaction score
- 1,928
Buy the ABC's book and the Lee Classic Turret. You will be good with both. Order the riser if you are going to get the Auto disk. It will save you some pain in the butt with the setup. It really should just come with the thing. I also like Lee's book.
Nemo288
Member
Besides the usual and excellent manuals the bullet and powder
makers offer (I started out with the Hornady manual), here are
a couple of other books not normally mentioned I have found to
be highly useful:
"Handloading For Hunters" Don Zutz. Maybe out of print I got a used copy via Amazon.
"Precision Handloading" John Withers. Goes thru a detailed record keeping and statistics
method to arrive at the most accurate ammo possible.
"Handbook For Shooters And Reloaders" P.O. Ackley. For decades considered the Bible
on the subject. Still highly entertaining and useful. Also out of print. Try ebay and Amazon.
Get both volumes.
"Any Shot You Want" A-Square Reloading and Rifle Manual.
Although not specifically for handgunners this overlooked book
is well written by several well known authors and I found it
superb and fun to read.
Obviously I belong to the "You can't have too many reloading manuals" club.
The slower you take it the more fun (and safety) you will have.
Enjoy!
makers offer (I started out with the Hornady manual), here are
a couple of other books not normally mentioned I have found to
be highly useful:
"Handloading For Hunters" Don Zutz. Maybe out of print I got a used copy via Amazon.
"Precision Handloading" John Withers. Goes thru a detailed record keeping and statistics
method to arrive at the most accurate ammo possible.
"Handbook For Shooters And Reloaders" P.O. Ackley. For decades considered the Bible
on the subject. Still highly entertaining and useful. Also out of print. Try ebay and Amazon.
Get both volumes.
"Any Shot You Want" A-Square Reloading and Rifle Manual.
Although not specifically for handgunners this overlooked book
is well written by several well known authors and I found it
superb and fun to read.
Obviously I belong to the "You can't have too many reloading manuals" club.
The slower you take it the more fun (and safety) you will have.
Enjoy!
Skip Sackett
US Veteran
Take a look at these pictures, they may help.
The first is a picture of a heavy roll crimp. One thing that needs to be said first is that neck tension needs to be the first thing to hold a bullet in place. That is why I size all new brass too. Uniformity.
A crimp can do two things. Aid in keeping bullet jump from happening, a bullet moving forward under heavy recoil. In an auto, keep a round from being seated too deeply from cycling or "re-cycling" the same round.
Another taper crimp: (Very light)
Bullet on the right pulled from a 45ACP round with a heavy taper crimp.
Compare the profile of it to the roll crimp above. It will help you understand better, I hope!
The manuals will only do so much, after that, you gotta do the work!
Take two rounds and leave the powder and primer out of them. Play around with your die settings. Learn the tools.
Have fun, be safe.
The first is a picture of a heavy roll crimp. One thing that needs to be said first is that neck tension needs to be the first thing to hold a bullet in place. That is why I size all new brass too. Uniformity.
A crimp can do two things. Aid in keeping bullet jump from happening, a bullet moving forward under heavy recoil. In an auto, keep a round from being seated too deeply from cycling or "re-cycling" the same round.
Another taper crimp: (Very light)
Bullet on the right pulled from a 45ACP round with a heavy taper crimp.
Compare the profile of it to the roll crimp above. It will help you understand better, I hope!
The manuals will only do so much, after that, you gotta do the work!
Take two rounds and leave the powder and primer out of them. Play around with your die settings. Learn the tools.
Have fun, be safe.
One of the easiest ways to get the correct crimp (others will disagree) Is buy the Lee Deluxe 4 die sets which come with the Lee Factory crimp die..
The revolver dies will roll crimp.
The semi autos will taper crimp.
You can not "over crimp" with them and are as fool proof as you can get.
Buy the Lee Manual also, it explains a lot, easy to read is inexpensive and has a consolidated list of just about every load for every caliber in the back section.
The revolver dies will roll crimp.
The semi autos will taper crimp.
You can not "over crimp" with them and are as fool proof as you can get.
Buy the Lee Manual also, it explains a lot, easy to read is inexpensive and has a consolidated list of just about every load for every caliber in the back section.
Similar threads
- Locked
