Glock Forum - GlockTalk banner
1 - 20 of 21 Posts

·
NRA Member
Joined
·
3,559 Posts
Discussion Starter · #1 ·
Based on some discussion about the Lee FCD in another thread, I need some education please.

Can someone to explain how the dies below differ in crimping for pistol ammo. I currently use the Lee FCD (with the knob on top) and set the crimp so the line on the bullet (if pulled) is almost non-existent.
  • Lee FCD (the one with the knob on top)
  • Dillon Crimp Die
  1. Do these crimp in different ways?
  2. Does one provide better accuracy over the other?
  3. I've seen in different posts that you should have no line, or barely a line around the bullet from the crimp. Is this true no matter what crimp die you use?
 

·
Registered
Joined
·
18,793 Posts
There is no difference in how the actual crimp is placed on the case with the Lee Carbide Factory Crimp Die and the Dillon Die.

The difference in those two examples is the Lee has a floating collar, with a knob that allows you to adjust the crimp without loosening the lock nut that holds the die in the press.

In general, it is best to just return the case mouth to straight in a taper crimp style round (one that headspaces on its case mouth). When loading mixed headstamps with varying brass thickness, case lengths, brass hardness (annealed properties), bullet surface hardness, how much "line" that is left on the bullet will vary. It is always going to be a big of a circular dance, one where you are shooting for "average", the average being straight case mouth.

On the accuracy results of Lee versus Dillon (or any other crimp die), what you are shooting for in crimp is no deleterious effect. The problem with the Lee die (the one with the knob on top, not the collet style version) is the carbide sizing ring placed at its die mouth can impact the case mouth as it goes by (worst in straight walled calibers when loading larger than nominal sized bullets like say, lead). This sizing effect can be deleterious to accuracy.
 

·
Registered
Joined
·
7,518 Posts
In a pistol, no. And it's not really a crimp at all, but rather a de-bell step which is just enough to take the bell off from the powder thru die. The crimp does not hold the bullet in place, it's the interference fit between the bullet OD and the case ID. Over crimping can lead to bullet setback.
 

·
Scottish Member
Joined
·
13,244 Posts
[QUOTE="9x45, post: 25007257, member: 19"]In a pistol, no. And it's not really a crimp at all, but rather a de-bell step which is just enough to take the bell off from the powder thru die. The crimp does not hold the bullet in place, it's the interference fit between the bullet OD and the case ID. Over crimping can lead to bullet setback.[/QUOTE]

As a general statement, this is not correct. It is true for some calibers, and not true for others - like .38, .357, .41 & .44 - there are probably others, but these are just one calibers I've roll crimped.

And even a taper crimp provides the interference fit to "hold" the bullet on a case that has been fired. Every try seating a bullet in a fired case that hasn't been resized or belled? It doesn't fit the same as with a taper crimp.
 
  • Like
Reactions: dudel

·
Friends Call Me "Flash"
Joined
·
5,265 Posts
I used to use a "zero bell" crimp on pistol cartridges using standard dies. In the past year or so, I changed to Lee factory crimp dies (FCD) in position 4 of the RL550B presses and Lee taper crimp dies for pistol rounds in position 4.

Proof of the effectiveness of these dies is found when using a precision cartridge gauge on your loads. Those FCD or Taper crimped rounds slip through the gauges like poop through a goose!

Flash
 

·
Registered
Joined
·
37,618 Posts
The only way a taper crimp provides any mechl lock is over crimping & creating a ledge. Ruins accuracy & can reduce neck tension, fact. Roll rcimp, Totally diff concept.
 
  • Like
Reactions: orangejeep06

·
Registered
Joined
·
7,518 Posts
For semi auto cases, especially 9mm, it is TRUE. Putting a bullet in a fired (un-sized) case makes no sense. It is not the correct ID diameter to provide an interference fit. So try this, load some 9mm without a crimp and shoot them in a S&W revolver. It doesn't need to be de-belled (crimped) because it does not sit in a chamber. The less taper in a semi auto, the less sensitive the round is to de-bell, such as a 10mm or 40S&W at .002" per side versus a 9mm, at .0055" per side.
 

·
Scottish Member
Joined
·
13,244 Posts
For semi auto cases, it is TRUE.
The above is correct, but that is not what you originally wrote.

Putting a bullet in a fired (un-sized) case makes no sense.
It given to show that sizing and the taper crimp provides the interference fit - not as a reloading practice.
 

·
Registered
Joined
·
18,793 Posts
Not sure I understand all of the nuance of the current debate ahead of me, but a taper crimp does absolutely nothing for bullet hold. The most unfortunate thing in reloading was the taper crimp, being named a "crimp" because it is nothing of the sort when properly done. It is to de-bell the case mouth and nothing more.

Nonstandard effects can be created by "over-crimping" with a taper crimp die, for instance, when loading LSWC bullet profiles in a 45 Auto. Taper crimping past just straight can aid in feed reliability in some guns. Also, many gamers crimp past straight with their taper crimp die to force the case mouth inward slightly as a prophylactic measure against snags on feed in, again solely for feed reliability.

The above measures are trade offs, reliability for accuracy (and potentially leading in the case of lead), but have absolutely nothing to do with bullet hold increase, accuracy or any other thing usually attributed to these practices.

Brass has more spring than lead/copper under it. When you force the case mouth into the bullet with a taper crimp die, when it is removed, the case mouth springs back more than the bullet does, hence, taper crimp cannot add to neck tension, it only removes it.
 

·
Banned
Joined
·
10,098 Posts
I'm not sure I understand how (over)crimping can lead to setback .... could you elaborate?

Alright. Take a barrel out of one of your pistols and look down the barrel from the chamber side. You will see that the chamber is slightly wider than the barrel and that there is a ridge in the barrel. That is what your case indexes on (stops the forward movement of the case). If you apply to much crimp on the case, it does not stop where it should and is pushed into this ridge. This compresses the bullet in the case and does not allow for it to release from the case and go forward. It is jammed into the case, and hence into the barrel. When you fire that round, the bullet will be jammed and all the pressure has to go somewhere. Where? Back to your slide, mag well and frame. The gun might very well grenade in your hand.

Do not crimp pistol cartridges, only remove the flair.
 

·
NRA & Second Amendment Life Member
Joined
·
1,613 Posts
Alright. Take a barrel out of one of your pistols and look down the barrel from the chamber side. You will see that the chamber is slightly wider than the barrel and that there is a ridge in the barrel. That is what your case indexes on (stops the forward movement of the case). If you apply to much crimp on the case, it does not stop where it should and is pushed into this ridge. This compresses the bullet in the case and does not allow for it to release from the case and go forward. It is jammed into the case, and hence into the barrel. When you fire that round, the bullet will be jammed and all the pressure has to go somewhere. Where? Back to your slide, mag well and frame. The gun might very well grenade in your hand.

Do not crimp pistol cartridges, only remove the flair.
Does that include shouldered cartridges like 357 SIG and 32-20?

Steve
 

·
NRA Member
Joined
·
3,559 Posts
Discussion Starter · #17 · (Edited)
Couldn't wait for the toolhead and Lee Universal Die.....Had to try the tumbler and dryer.

I dumped the powder hopper, inhibited the primer feed and decapped ~500 pieces of 9mm brass......lotsa room for more 9mm in the tumbler.

Used 2 squirts of Dawn and an 40 cal case of Lemishine and ran the FA Tumbler for 2 hours.

Used 3 of the 5 trays of the Dryer for brass (and they wern't full.....lots of extra room on each tray) and I put the pins in the very bottom of the dryer. There are 3 openings around the bottom of the dryer to allow air flow so I kept the pins in away from the openings.

So far I'm impressed with both the tumbler and dryer.

I was a little concerned about the dryer based on a couple of reviews I saw. They didn't mention the fan blowing the hot air down through the trays, and a big complaint was how the trays didn't fit together tightly........come on people.....you just need to be smarter than the dryer.....I had no trouble at all getting the trays to fit tightly and the bottom where my pins are, are just as hot as the top tray.

IMO this is working out perfectly so far.

I just checked the dryer, and after the brass are almost too hot to touch and the pins are perfectly dry........I'm very satisfied.
 

·
Banned
Joined
·
10,098 Posts
Couldn't wait for the toolhead and Lee Universal Die.....Had to try the tumbler and dryer.

I dumped the powder hopper, inhibited the primer feed and decapped ~500 pieces of 9mm brass......lotsa room for more 9mm in the tumbler.

Used 2 squirts of Dawn and an 40 cal case of Lemishine and ran the FA Tumbler for 2 hours.

Used 3 of the 5 trays of the Dryer for brass (and they wern't full.....lots of extra room on each tray) and I put the pins in the very bottom of the dryer. There are 3 openings around the bottom of the dryer to allow air flow so I kept the pins in away from the openings.

So far I'm impressed with both the tumbler and dryer.

I was a little concerned about the dryer based on a couple of reviews I saw. They didn't mention the fan blowing the hot air down threw the trays, and a big complaint was how the trays didn't fit together tightly........come on people.....you just need to be smarter than the dryer.....I had no trouble at all getting the trays to fit tightly and the bottom where my pins are, are just as hot as the top tray.

IMO this is working out perfectly so far.

I just checked the dryer, and after the brass are almost too hot to touch and the pins are perfectly dry........I'm very satisfied.

I never dry the pins, just put them back in the tumbler with a Pin Transfer Magnet. They don't rust.

https://www.midwayusa.com/product/3...dia-transfer-magnet-for-stainless-steel-media


My dryer was deep-frying my brass and tarnishing it, went back to the seller. Make sure yours is not having the same overheating defect. I don't trust them.. would not let them run while being out of the house.

Mine was at 156F when on the lowest setting, which should have been 90F.


 

·
Registered
Joined
·
3,243 Posts
I thought about getting the dryer but wanted to see if I could do something with a fan I had laying around. So far so good.

I've been cleaning between 800 and 900 9mm at a time. Got a deal on the Frankford Arsenal Brass Cleaner 1qt when I bought the tumbler and so far it's been great. I have about 4K 9mm that I cleaned at the end of last year and it's still nice and shiny. When the brass cleaner is gone I'll experiment with other products.

Glad to hear you're happy with your set up.

Dave
 
1 - 20 of 21 Posts
Top