Question about dies and procedures

Some dies do expand and size the casing at the same time. As long as everything is set right there isn’t anything wrong with seating and crimping at the same time. Some prefer to isolate the two from each other but I don’t. It’s one less pull on the press and faster production. Just take the time to fine tune your reloading process.

1. For most straight walled pistol and rifle cases, the sizing die squeezes the case back down to the correct diameter. If the mouth of the case is flared when inside the die, it would be squeezed back when the case is pulled out of the die. Bottleneck cartridges can size and expand the neck of the case in one step, but flaring/belling the mouth still needs to be a separate step like in the straight wall cases.
2. Many bullets have a groove in them to accept the crimp, so it really isn't causing a problem with pushing the bullet into the case for the last few thousandths of an inch. Other calibers use a taper crimp, that is really only intended to squeeze the case mouth flare back down flush and isn't biting into the bullet.

Sizing and expanding is combined for bottle neck cartridges. But with straight walled cases it can not be done. The bullet only moves just a little during the crimping process. Seating and crimping at one time is faster and saves a station on a progressive press. Seating and crimping separate is easier to adjust. Maybe. I am addicted to the expensive seating dies that do not crimp anyway. There are different levels of accuracy and different levels of interest in the parts of the process in reloading. Some people on the forum freak out over small variations of things that I never even considered measuring.

Pistol case and rifle case resizing are a bit different.

The body of a bottleneck rifle case is resized to the proper specs that will fit into a chamber, however, the neck must be resized to a small spec and therefore that area gets a bit more resizing. As the case is pushed up into the die, a deprime stem with expander ball (some have a tapered "ball") goes inside the case and 1) pushes out (deprimes) the old primer, and 2) on the way out, the expander ball expands the neck to a size that is about .002 smaller than the bullet. This gives "neck tension" and holds the bullet in place prior to firing. This is normally done all in one die.

A straight-wall pistol case has to be treated a bit differently. The first die will "squeeze" or resize the case to a bit smaller than chamber specs except down toward the case head which will be to specs. Undersizing must be done in order to hold the bullet. The second die, the expander/flare die will expand the case back out to specs plus flare the case mouth should you desire a flare to facilitate bullet seating.

As for seating/crimp, it's a matter of preference more than anything. If you want to seat and crimp in the same die, then that's what you buy. Should you want separate seat and crimp operations, then you can buy the addition die from most companies or buy from a company that gives you the dies in one package.

Personally, I've always sized and crimped with the same die when I crimp which isn't all that often. I've done it that way for a long time and just don't see the need to change. Now, I will say that I do crimp hot loaded pistol cartridges like .357 and .44 Mag. I don't crimp any of my rifle cartridges, but I do know what the fit between bullet and case neck is and have tested those enough to know set-back won't be a problem.

We are assuming you are studying reloading for straight wall cases by your questions but - are you studying reloading in general or for a specific round?

9mm and .40 will be best served by a separate taper crimp die, making it a four die operation.
If you load real .44 revolver bullets with a crimp groove, you can get a good crimp in the seating die, but if you use ungrooved plated or coated bullets, best to get a separate taper crimp die for it, too.

In a bygone day, when I started reloading, the three die pistol set was standard, but there was still a lot of discussion about the old two die sets and how you had to expand a lot in the sizing die in order to have a little flare left when you pulled the case back out of the die.

Many reloaders seat and crimp in one operation, but the die must be adjusted just so. Too much one way and no crimp. Too much the other way and you can get bulged cases or damaged bullets. Expanding has been covered very well above.

While 9mm and 40 S&W aren't difficult to reload but a revolver cartridge is, in my opinion, easier for a new reloader. OAL is not critical, case dimensions are less critical, and crimping is really straight forward, just roll the mouth of the case into a crimp groove or cannelure.

Keep studying, but don't overthink the process. A good "How To" text is "The ABCs of Reloading". Lots of good basic How To and explanations of equipment and components, and safety practices.

Go slow. Double check everything. Most important, have fun...

The dies will stand some amount of dirt; I did not used to tumble .38 brass to be loaded with wadcutters for PPC matches. Nowadays, I dry tumble in nutshell media.
But people are buying more and more equipment and doing more and more prep work to get pretty ammunition. I have gear for wet tumbling but have done it only for black powder cases.

Concerning crimping, you can get away with doing both seat and crimp in the same step depending on the bullet and how the die is set.

Example, a 44 mag with a bullet such as the Keith 429421 can handle both seating and crimping together as it has an ample crimp groove.

9mm with a lead bullet likely will need to separate the operations as a taper crimp will scrape lead while the bullet is still moving.

But 9mm with a jacketed bullet will handle combining the operations because the bullet is tough enough to withstand the abrasion.

Bacek said:

Being grateful for the wisdom you share, I still have questions:
How bad for the carbide dies it is to de-prime and size the case picked from indoor range without cleaning them first?

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It's actually bad on both. You end up grinding the grit into the brass and sizing ring. Then every thing you run through the die will have scratches and gouges. Though carbide is extremely hard brass can and does stick to it. This in turn will hold the gritty material scratching your brass Now you don't have to be squeaky clean like a lot of us to with out wet cleaning systems. For decades I just wiped the outside clean with a rag before sizing. Had no cleaning device except soap and water.

Bacek said:

How bad for the carbide dies it is to de-prime and size the case picked from indoor range without cleaning them first?

Click to expand...

You want to get the dirt off by at least wiping it on a rag. You don't want any grit getting in there scratching the die and/or the brass.

My process: I de-prime some really grungy cases using a Universal De-Capping die or a hand de-capping tool. Then I wet tumble them clean. I don't use the press and universal de-capping die much anymore because of how messy my press gets with the dirt and debris from the dirty cases. I wouldn't want that dirt/grit anywhere my sizing die.

I have no idea how many 9mm rounds of all kinds that I’ve seated and taper crimped in the same operation - a lot over too many years. Same for.40, but you need to understand what an “unsupported case” is for .40. Look that up especially if you own a Glock and some SIG .40s. Also “Glock Smile”. Needs to be figured into your education.

All you really need to do when crimping rimless cases like 9mm, .40 and .45 is to remove any flare you may have put in to facilitate bullet seating. Rule of thumb is wall thickness at the edge of the mouth x 2 (each side of the case) + bullet diameter. So, if you have .011 wall thickness x 2 = .022 + bullet diameter, and here we’ll use .355 = .377. IMHO, you don’t gain anything by over crimping.

Rimmed cartridges like .357 and .44 can benefit from roll crimping a bullet with a cannelure, but I only do so for heavy loads.

Whether you crimp in one step or two all depends on your preference. I personally have never had any problems w/ one step, but then that’s all that was back in the day, and it was the way I learned. It’s pretty easy; just read the instructions and take it slow. If you already have a standard 3-die pistol set, give it a try.

It would be heresy on this forum to suggest anything other than Lee for a 4-die set, but you can buy the separate crimp die from all die manufacturers that I know of. Lee’s good and the price is right. I’ve really never met a die that I did not like .

NMexJim said:

I’ve really never met a die that I did not like .

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Much wisdom in that, Jim.

1--- I tumble my dirty brass in nutshell media.
2--- I resize the brass and deprime at the same time. The press gets a little dirty but I clean it after every session (approx 250 to 500rds). Case gets primed on upstroke.
3--- I flare case mouth and add powder.
4--- I seat the bullet and crimp together,one die for .38spl and seperate dies for seating and taper crimping for .45ACP.

Bacek said:

How bad for the carbide dies it is to de-prime and size the case picked from indoor range without cleaning them first?

Click to expand...

An indoor range is usually fairly clean, but it's always good practice to at least wipe the brass down. This "handling time" gives you time to inspect the brass and make sure it's worth reloading. Lots of brass is left behind because it's not actually reloadable brass, or because it can't be loaded again for numerous reasons.

Now brass left on an outdoor range is a completely different story. There you do need to be highly concerned and inspect a lot more carefully because grit can adhere to the outside and small pebbles can enter the case mouth. Also some minerals in the ground can attack brass that's left outdoors for extended periods.

Hope this helps.

Bacek said:

Being grateful for the wisdom you share, I still have questions:
How bad for the carbide dies it is to de-prime and size the case picked from indoor range without cleaning them first?

Click to expand...

I de-prime on my Rock Chucker before wet tumbling. I won't run dirty fired brass through my Dillon pistol dies, for any reason. Same procedure for my rifles except for the Lee factory crimp die at the end.

Bill

I dry tumble and then resize. I do not see the point of resizing dirty cases. I do not often tumble after depriming. I have more or less come to repriming without cleaning the pocket or sometimes I do it by hand with a RCBS tool.

It depends on how dirty the cases are for me. If these are once fired cases that I've recently cleaned and loaded and never let them hit the ground, I'll resize and de-prime in the resize die. If these are dirty cases, range brass, etc, then I'll de-prime on my single stage with universal de-capping die, then tumble, then back out the the de-capping pin in the sizing die when I load them.

The carbide sizing inserts on sizing/depriming dies are waaaaay harder than any cartridge case that is being reloaded, including steel cases. Grit or sand on a case may become lodged in a sizing die, but that is rare. I reloaded for 12 years before I got a tumbler, just wiping the case with a solvent dampened rag as I did my initial inspection. Never scratched/damaged any dies or chambers. I'll guess at the most reloaded cartridges for me is a toss up between 38 Special/357 Magnum and 44 Special/Magnum. The 38 Special since '72 and the 44 Spec/Mag. since '88. Several thousand of each with tens of thousands of 38/357 (many cases just wiped). My sizing dies appear as new and cases sized are the same size/finish as when the dies were brand new, meaning it's pretty dang hard to wear out a carbide sizing die...

I understand you are still in the researching stage, but don't overthink reloading. Case prep is mainly "Metal Working 101". The whole process is straight forward and logical, but personal preferences play a very large part of an individual's reloading process. (Like case cleaning; probably the most talked about, most over thought part of reloading, but the least important. Ask 20 reloaders about case cleaning/tumbling and you might get 40 different answers/suggestions)...

Go slow. Double check everything. Most important, have fun...

How bad for the carbide dies it is to de-prime and size the case picked from indoor range without cleaning them first?

Click to expand...

When I first started I would rinse any major dirt off my brass then just let it soak in a bucket of soapy water for a few days then rinse and dry.
(placed on an old towel in the sun or in the corner of a room inside when outside weather wasn't nice)
I loaded quite a bit of 9mm this way before I bought a tumbler.
(to many cases to wipe by hand)

A hose, a bucket and some dish soap will get rid of most of the curd that might damage your dies. Cost $1 for a bucket at the .99 cent store if you don't have one, $3 for a bottle of dish soap.

A dry tumbler, or better yet a wet tumbler will give you shiny brass but it does not have to be shiny to work just fine.

PS: I had a dry tumbler and moved to wet with pins which makes the brass look like new, but the tumbler is something you can worry about down the road if you decided reloading is for you.