Setting expander for proper bell question

[Wing Rider]

I was just reading the sticky thread about crimping and I ran across a post that stated that the bell of the brass by the expander was 0.005" and someone questioned this and stated that that was excessive bell. While setting up my new press, the instructions stated to set expander so that the bell was approximately 20 thousandths bigger than the case size. If I am doing my math correctly that would be 0.020" which is a lot more that 0.005". I am loading 357 magnum with XTP jacketed bullets. I dont want to expand any more than needed to help prevent excessive stresses on the brass. Any suggestions on what should be the proper bell size?

 

[Bandit67]

Expand the mouth just enough for the bullet to start into the case without falling over and don't worry about measuring.

 

[k4swb]

I am loading 357 magnum with XTP jacketed bullets. I dont want to expand any more than needed to help prevent excessive stresses on the brass. Any suggestions on what should be the proper bell size?

You just answered your question. I've been hand loading for a long time and never have measured the flair. I just set it to whatever it takes to get a smooth insert.
I'll also admit that I've never measured a crimp. I just crimp til it looks right.

 

[243winxb]

math

Flare can be measured. The .005" is minimum. But the die needs to be adjusted/set on the shortest brass, if trim length is not all the same.

The newer "M" type expanders are different then the old tapered type that i use. Different i would guess.

Info in Post #2 works. Best not to over think it.

 

[Bfh_auto]

I trim every piece of brass so I just set one to barely fit a bullet. There is no need to measure because all you are going for is function.
I crimp to make it look like a factory round.

 

[nettlle]

I flare enough to keep the casing from shaving lead from cast lead and the coating on cast coated bullets. Once I find enough flare to do both I adjust the belling die to flare a little bit more than that.

 

[Walkalong]

Expand the mouth just enough for the bullet to start into the case without falling over and don't worry about measuring.

Bingo!

 

[Ole Joe Clark]

If you trim bottleneck cartridge cases, a nice clean chamfer of the inside of the case will prevent bullet shaving.

Have a blessed day,

Leon

 

[9mmepiphany]

I likely expand too much, but it works well when I'm loading a coated bullet on a progressive press. I want the bullet to stay centered in the case mouth as it travels over to and into the seating die and I want the bullet to seat without shaving any of the coating off the lead. This is on cases which have been trimmed to a uniform length and had their mouths chamfered and beveled

I'm using the Redding expanding die with the same profile as the Lyman M-die. I lower it until it expands the mouth enough so that I can put a bullet into the mouth...after taking it off the shellplate...and when I remove the bullet, there is a slight "pop" as I break the seal between the bullet and the brass.

I can gently invert the cartridge without the bullet dropping out

 

[ArchAngelCD]

Expand the mouth just enough for the bullet to start into the case without falling over and don't worry about measuring.

Yes Sir, won't go wrong there.

 

[buck460XVR]

I tend to use too little flare with the hopes of not over stressing the brass. Then it's a balancing act on the press till I get the bullet started. Chamfering the inside of the necks can reduce the amount of flare needed too.

 

[rfwobbly]

I am loading 357 magnum with XTP jacketed bullets. I dont want to expand any more than needed to help prevent excessive stresses on the brass. Any suggestions on what should be the proper bell size?

You've got a special case with revolver cartridges. You need to flare the case for seating, but then the roll crimp forces the brass the opposite direction. Over-belling with over-crimping will lead to early demise of the brass due to cracking at the case mouth.

If you think about it, it's really the total displacement of the brass you need to consider. Therefore for maximum case life, you want to use the minimum flare with the minimum crimp which will get the job done. Don't think there is one, single definitive number you can put on that. Plated bullets with a rounded base require less belling than jacketed, which require less than lead, which may require less than coated lead. It's all done on a case-by-case basis... no pun intended.

 

[Jim Watson]

I am more concerned with keeping my bullets smooth than I am with case life in common calibers.
So I probably flare more than the Internet Standard.

 

[mdi]

Don't overthink this process. All you are doing when you flare a case mouth is providing an "entry way" for the bullet to enter the case without damaging the bullet (it can be difficult to push a .357" slug into a .354" tube without a tapered "entry"). K.I.S.S. and use as much fare as you need to get good ammo now, and worry about case life later. The only limit for "too much" flare is running the case up into the seating die. Too much flare and the case mouth hits the die and won't enter the die.

 

[Eugen]

Expand the mouth just enough for the bullet to start into the case without falling over and don't worry about measuring.

As a novice reloader I was taught this. But, as I began to reload I noticed a measurable difference in belled case mouth size depending on how one interprets "without falling over". For the sake of discussion how do others interpret that phrase? Does it mean "without falling over"..and landing on your foot, or to the other degree, does it mean "without falling over" and leaning at a less than vertical angle? Yes, I am splitting hairs, but want to learn from the responses of experienced reloaders. From my own limited experience I have found the projectile can lean considerably on the minimally belled case mouth and still seat vertically at my chosen C.O.L. Is this all good or should the bell be sufficient to enable the projectile to seat nearly vertically?

 

[Blue68f100]

For hand gun most of my seating dies have the drop down alignment sleeve to straighten the bullet up. I bell a min so it sets pretty straight, more so for lead to keep from shaving the bullet. I normally will give the brass a spin as the sleeve contacts it to make sure the bullet aligns, straightens up. Also with lead and SWC I use a special seating stem which only pushes on the shoulder of the bullet. This too helps make sure the bullet goes in straight. If your contacting on the side you will get a little rocking. If the bullet happens to be a WC with a flat top the flat seating stems works fine but it must be started straight since there is no action that will align it. With 357/38's I debur the mouth when I first use the brass to remove any sharp edges. I only do this once unless for some reason I have to trim the brass.

 

[Wing Rider]

After reading the comments given, I readjusted my bell to barely spread and the bullet still worked well in the seating die so I am going to leave it at the minimum bell to prevent over working the brass. Thanks for the input.

 

[Walkalong]

I don't worry about "case life" with belling, I just don't want to hurt neck tension with too much. Minimum belling to not scrape bullets is how I set it up. I have switched almost all of my expanders to the M-Die style expander.

 

[FROGO207]

I was taught to expand the neck enough that after placing the bullet and pushing down slightly you could lift the round by the bullet. I still do this for coated bullets but for the others expanding enough that the bullet will stay square in the mouth without tipping is what I do now. I also have expander buttons/sleeves that are set up for lead and others that are set up for jacketed/plated. Getting enough tension is the name of the game. Less working of the case is a side benefit IMO. I tried crimping and not crimping my rifle ammo and found it more accurate without a crimp. This also falls into the minimum brass working camp as a side benefit along with annealing every three loadings to extend brass life. YMMV

 

[Iron Sight]

Note how the Lyman M style works. I like it.
There’s another expander die maker using the same system but cannot remember there name?

 

[Walkalong]

That's a poor example, there are much better pics out there somewhere. I'll look around.

 

[Walkalong]

Nope, not this one.

 

[Walkalong]

This fellow covers it.

https://www.m4carbine.net/showthread.php?203796-9mm-frustrated-with-Hornady-locknload

In reality you have to go way to deep to get to the third step which is a regular flare and isn't needed anyway.

This pic is a little better.

 

[9mmepiphany]

In reality you have to go way to deep to get to the third step which is a regular flare and isn't needed anyway.

I've also found that to be true.

I'll go further and note that when I over expand like that, the case mouth meets resistance entering the seating die

 

[cfullgraf]

Good information posted so far.

I use several of the mouth expanding/belling techniques.

The only thing I can add is that I like to chamfer the inside of the case mouth a bit, particularly when loading cast or coated bullets. It helps prevent shaving the bullet some. It's a one time thing unless you trim the case.