Bulging cases, what am I doing wrong?

[postoak]

Why do you need a special expander (flare) for straight wall cartridges? Regular cartridges don't have them and you can seat the bullets.

 

[fourfive8]

That's the point about the bulge showing on the OP's straight wall. A regular bottle neck case will also do it IF the neck is not expanded enough after sizing and the bullet base is seated in the neck. Take the neck expander button out of a sizing die for a regular bottleneck case, size the case and seat a bullet half way into the neck- the bulge will show in the neck. Usually the expander button in the bottleneck sizer die expands the neck enough to minimize the effect or the bullet's base is seated at or just below the shoulder junction and the bulge won't show anyway. Straight wall cases are slightly different in how they are sized and expanded.

A flare is different form an expand. A flare is a small funnel formed on the case mouth to facilitate bullet start during seating. Neck expansion is usually for all the case neck that will hold the bullet shank when the bullet is fully seated.

 

[postoak]

So the OPs Hornady die leaves the inside at .441", the Redding die leaves the inside at .452" and neither expands the inside, they just flare the mouth, whereas your M die expands up to .456". The question is why the Lee and Redding dies were made to size down so small and did you need to special order your M die to get the .456" expansion?

 

[fourfive8]

Actually, the expander plug for the expander dies for those type straight wall cartridges by both Lyman and Redding are very similar. The sizer die can only have a decapping pin for true straight wall cases. I just remove the decapping pin on all sizers and use a universal decapper die. That may have been confusing in the first post with the pic- my error. They are two different dies... the sizer only sizes and the expander die has larger ID so it doesn't size- only holds the expander plug. Here's another pic showing 4 slightly different 45 cal rifle expander plugs that will fit both the Redding Exp and the Lyman M die. The loaded 450/458 cartridge in the previous pic was sized with the Redding sizer to a neck inside diameter of .450". The neck expander die with .454" expander opened the neck ID to about 453-454"... depending upon springback.

Pic from left to right 4 different expanders that will fit either the Redding Exp die or the Lyman M.
The main sizer diameter and minor flare diameter of each is:
1) .454 .460 2) .454 .459 3) .457 .460 4) .449 .460

I use the # 1) .454 .460 and end up with a neck ID of about .453-.454" again depending on brass springback because of annealing, age, thickness or brand of brass. I adjust the expander in the die to only use the .454" portion not the .460" portion. I do not get the "bulge effect" after seating a .458" bullet as was the OP's concern. If the sizing die is near minimum and sizes that minimum very far down the case neck and into the body area. And if there is a large difference in diameter between that neck area after sizing/expanding and the diameter after seating the bullet... a bulge will show. Again largely cosmetic and odd looking in addition to being likely off axis. It's the off axis part that would negatively affect accuracy. I've shot a bunch like that and doesn't seem to cause much issue except a very small loss of accuracy. BTW, straight wall handgun ammo many times shows the bulge effect for the same reasons.

 

[sestoppelman]

Now me, when I get this horrific condition in my loads, why I just lay them on the loading bench and lay a tire iron on them and give them a few good whacks with a mallet till the that nasty ol bulge just sort of disappears! Then I load them in the old rifle and shoot the snot out of them. That'll show 'em not to get all bulgy about it next time by golly!

 

[postoak]

When I was a freshman in college I had a Ruger Blackhawk in .41 Magnum and the RCBS die I had produced those ugly-looking loads and I just shot them, but today I'd not tolerate it. I also remember loading .38 Special, .444 Marlin, and .45-70 and none of those came out looking bad. But it's been too many decades for me to remember what the dies were like.

 

[Hogpatrol]

My 2¢, what you're doing wrong is using Hornady brass. That brand is the last I'd use. YMMV.

 

[postoak]

fourfive8 - I understood you and your system makes perfect sense.