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View Full Version : Input on belling pistol cases please.



NewbieAKguy
10-21-2013, 04:47 AM
I want to apologize upfront for a coming wave of questions from me on reloading. Please have patience with me!

That being said, I've made it to stage 2, installing and adjusting the powder die. But my excitement was dampened by adjusting the bell and measuring cases for before and after belling. I'm reading in manuals that the case mouth should be approx. .002 bigger than case body; but I guess the bitch of it is measuring the spot on the body the same place before and after checking the bell. I guess the curve ball to me is that despite appearances the 9mm Luger case isn't a true straight wall case.

Is there a trick as to measuring case bodies or is this just the nature of the beast? Or is it easier to just open the bell incrementally until a bullet is able to sit upright on its own in the case and stop?

Thanks again for the help fellas.

res45
10-21-2013, 10:46 PM
The problem with measuring 9mm cases is that all the major brands/headstamps are different thicknesses and lengths so your never going to get a true measurement if your measuring random case. Before I ever start reloading 9mm I separate all cases by headstamp even within the same brand name like CCI Blazer Brass or CCI Lawman cases.

Personally I've never measure the case mouth flair. I basically just apply/use enough flair on the case mouth so the bullet will start into the case easily, sometime you will need to add a hair more when loading cast lead bullets. Just make sure you don't put to much flair on the case mouth where it make it hard to start the case into the taper crimp die which is really not a crimp die at all.

A properly adjusted taper crimp die may or may not increase bullet tension by as much as 10%. Screw that die down further and the casing starts to buckle releasing it’s grip of the bullet. You know the results from there, bullet setback.

Bullet tension is determined by:
1. The resizing die.
2. The expander plug. (Bell mouth die)
3. Case wall thickness.
4. Bullet diameter.

The best way I know to properly set up your taper crimp die is first resize a casing and measure the mouth diameter with a set of calipers. Now take that empty casing and run it through the crimp die and measure again. The two measurements should be the same, or up to .002 smaller. Remember though less is more when it comes to taper crimping.

Before you get to carried away and load up a bunch of ammo take the barrel of your pistol and do the plunk test to make sure your rds. drop in and fall out of you chamber fairly easy. Also load your test rds. in the magazine to make sure they don't bind in the mag and hand chamber all the rds. to make sure they feed properly.

Schuetzenman
10-22-2013, 05:56 AM
I've never measured the belling or flaring of a cartridge case. I simply adjust the die to give me enough to have the bullet stay in the case in an upright position for seating. On taper crimp the last post is the way to approach it, as minor a crimp as possible is best. Go heavy on the taper crimp and you crush in the side walls of the bullet that need to be in contact with the rifling.

NewbieAKguy
10-22-2013, 07:30 PM
Sounds good. Thanks for the advice guys. I think I've got it now to where the bullet stays upright like S-man describes it.

N/A
11-03-2013, 08:43 PM
I guess everyone has their own littlw ways of doing things. After I resize the cases, I put in the die to bell the case mouth. Then i back off on the plug, run the case into the die, and then turn in the plug till I fell it hit the case. Then I turn it in a little at a time and run the case into the die. Take the case out, fell the bell with my finger tips, and then check to see how it fits into the bullet seating die. Then check a bullet to see how it fits to the case.

I repeat this, till I'm satisfied with just enough bell that will start the bullet and still fit smoothly into the bullet seating die.

As for crimp; I set the bullet first and then if I want a particular lot to be crimped, I back off the bullet seating plug, and then turn in the die slowly untill I can just detect a crimp by visual looking. Check it everytime you turn the die in a little bit.