Case Expander Necessary for Pistol Cast Boolits?

[BigBoreReloader]

Hi All... the deeper down the rabbit hole I get into reloading cast, the more questions I have! Today's question is around case expansion for pistol cartridges. Specifically, I am reloading 500 S&W Magnum in this case (but applies to all). The boolits I am loading are 0.501" (so 0.01" wider than the typical Jacketed, as you'd expect). My current expander die really just bells the case, but is there a real need to use a proper expander to produce a bell and widen the case? If so, is there a standard rule as to how much to expand relative to boolit diameter (i.e. I've read keeping case tension to ~0.003-0.004 below projectile diameter is appropriate?).

I tend to think expanding would be necessary. If so, any thoughts on the NOE Expander Plugs?

[country gent]

I would recommend a expander type die for the reason most brass varies and dies size on the small size then the expander opens up to desired dia. Most dies size to .002-.003 small then the bell expander open up to get correct tension. In this way variations in brass thickness dont matter.

[BigBoreReloader]

I would recommend a expander type die for the reason most brass varies and dies size on the small size then the expander opens up to desired dia. Most dies size to .002-.003 small then the bell expander open up to get correct tension. In this way variations in brass thickness dont matter.

Thank you, sir. I figured as much.

[Rfeustel]

I really love NOEs bullet expanders that fit the lee universal expanding die. Check them out the dimensions will answer your question (NOE has figured this one out). They are two-step flare expanders, +.002- -.002. Great neck tension and flare for a given sized cast. Works great on an indexing press with a bullet feeder.

[BigBoreReloader]

I really love NOEs bullet expanders that fit the lee universal expanding die. Check them out the dimensions will answer your question (NOE has figured this one out). They are two-step flare expanders, +.002- -.002. Great neck tension and flare for a given sized cast. Works great on an indexing press with a bullet feeder.

Thanks... just orders a few!

[mdi]

It's kinda difficult to shove a .357" lead plug into a .354" brass tube without some sort of "entry way". "M" style expander dies are great, but I reloaded cast bullets for many years before I got one. Almost all my casting was done with wheel weights (I worked in a garage and WWs were plentiful) and never had any swaging or shaving when I used a plain flare in the case mouth. I used Lee powder through flaring dies, Lee loader flaring tools, punch/chisel heads and some home made flaring tools, brass rods with a taper machined in the end. I even flared some 38 Special brass with a 30-06 case (shoved a 30-06 case into the 38 case mouth, pushed hard and twisted. Worked OK).

[iflyskyhigh]

As an aside. Properly belled / expanded case can have a “yuge” effect on accuracy with lead/coated bullets.

On the Brain Enos forums someone was recommending what I thought was way to much bell / expansion for 9MM. But I tried it and accuracy improved immensely.

Along with with proper crimp makes all the difference.

Have started doing the same “bigger than usual” bell/expansion in .40 and .45 with similar good results.

[BigBoreReloader]

As an aside. Properly belled / expanded case can have a “yuge” effect on accuracy with lead/coated bullets.

On the Brain Enos forums someone was recommending what I thought was way to much bell / expansion for 9MM. But I tried it and accuracy improved immensely.

Along with with proper crimp makes all the difference.

Have started doing the same “bigger than usual” bell/expansion in .40 and .45 with similar good results.

Great point... I had read something similar so curious to see how it affect my loads.

[243winxb]

500 S&W Magnum-I've read keeping case tension to ~0.003-0.004 below projectile diameter is appropriate.

I think this is correct. Dont want bullets jumping crimp.

[BigBoreReloader]

500 S&W Magnum-I've read keeping case tension to ~0.003-0.004 below projectile diameter is appropriate.

I think this is correct. Dont want bullets jumping crimp.

Thank you, sir... proceeding as such.

[Three44s]

Well I think you are headed in the right direction!

Enjoy!

Three44s

[kevin c]

It was pointed out to me by the wise heads here that the 9mm bullets I so carefully sized to 0.357" weren't staying that way with my factory dies (undersized case sizer combined with the mouth flare only "expander"). That was likely the cause of the leading I experienced. I eventually had Lathesmith make me a M style expander that keeps my slugs at 0.357 after seating. No leading, and, while I'll allow that other changes have been made, I've been seeing better groups too.

[Old Caster]

In general the smaller the caliber and the deeper the bullet is seated when shooting pistols the more important it is to expand the case and the shorter the case the same circumstance. When loading some 115 grain bullets in 9 mm cases with a standard 9 mm die set I found the the bullets were swaged down to .351 after pulling it out of a loaded case. The BHN was around 10 and some of the bullets would enter the target sideways at 25 yard and the group was around 4 inches out of an accurized Beretta 92 FS. My friends and I could not get 32 long Walthers or Bennelli's to shoot accurately until we used a larger expander to keep from swaging the bullets down. When I started to shoot a Pardini 32 ACP I had to use a bigger expander there also and it definitely bulges the brass. Different brass had an effect too because some are tapered thicker closer to the front of the brass. A lot of people only use 38 wadcutter brass to shoot wadcutter bullets in guns like the model 52 Smith because it is made to not swage down the longer wadcutters since the brass is not tapered until a longer distance from the front of the brass. I don't have this problem with 45 ACP or 44 Magnum and I doubt you will have a problem with something as big as you are reloading.

[BigBoreReloader]

In general the smaller the caliber and the deeper the bullet is seated when shooting pistols the more important it is to expand the case and the shorter the case the same circumstance. When loading some 115 grain bullets in 9 mm cases with a standard 9 mm die set I found the the bullets were swaged down to .351 after pulling it out of a loaded case. The BHN was around 10 and some of the bullets would enter the target sideways at 25 yard and the group was around 4 inches out of an accurized Beretta 92 FS. My friends and I could not get 32 long Walthers or Bennelli's to shoot accurately until we used a larger expander to keep from swaging the bullets down. When I started to shoot a Pardini 32 ACP I had to use a bigger expander there also and it definitely bulges the brass. Different brass had an effect too because some are tapered thicker closer to the front of the brass. A lot of people only use 38 wadcutter brass to shoot wadcutter bullets in guns like the model 52 Smith because it is made to not swage down the longer wadcutters since the brass is not tapered until a longer distance from the front of the brass. I don't have this problem with 45 ACP or 44 Magnum and I doubt you will have a problem with something as big as you are reloading.
Thank you! I have fired a few test rounds of 535 grain cast 500 Mag without issue. I ordered some NOE expanders, so I will give that a try as a comparison. Appreciate the information!

[reedap1]

The NOE expanders are the best and most versatile on the market and pricing is good. But to answer your question "are expanders necessary?" in reality no if your expander ball opens the neck sufficiently to prevent the bullet from shaving on seating. However, a better answer is "yes, they help a great deal for consistent seating of the bullet" and as other posters have stated will dramatically affect accuracy. Just be sure to expand the very minimal amount to seat a bullet.

[BigBoreReloader]

The NOE expanders are the best and most versatile on the market and pricing is good. But to answer your question "are expanders necessary?" in reality no if your expander ball opens the neck sufficiently to prevent the bullet from shaving on seating. However, a better answer is "yes, they help a great deal for consistent seating of the bullet" and as other posters have stated will dramatically affect accuracy. Just be sure to expand the very minimal amount to seat a bullet.

Thank you... I actually just reloaded a bunch of 500 Mag cast using the NOE expanders. They definitely sat much better than my first batch where I just belled the mouth. I hope to test them out this/next weekend.

[cwlongshot]

A other Lyman M Die fan here. Ill always have one for anything I load cast in. Period.


There Fe copies some work just as well. I been using the M die before the rest.

CW

[armoredman]

I am cheap, so I just adjusted the Lee powder through expander die to give a slightly wider flare, and sized my boolits down to .356, no worries in 9mm, good accuracy and no leading when powder coated. The seater has been adjusted to gently iron out that flare, because I wouldn't use the FCD on a cast slug. Now I DO have an actual Lee expander, (read neck flaring), die, but I have that set up for 5.56mm right now.

[Rick459]

another trick to help accuracy with lead bullets is to champher the case mouths either using a VLD champher or the K&M inside neck reamer that uses a 4 degree cut angle..
Rick

[Cosmic_Charlie]

I have noticed the powder through expander setup from Lee seems to,work just fine with my cast pistol loads. I do have some of the Noe M style plugs but I have not been using them lately. I used them for 30 cal rifle cast loads a while back.

[gwpercle]

Yes a neck expander , if not required ... sure makes life a lot easier .
I find the best option to be a Lee Universal Neck Expander ... in truth it is a neck flaring tool but sometimes a flare is all you need ... like when seating gas checked boolits ... And Noe now makes true M-die style plugs you can order and use in the Lee Universal Die body ... order these much cheaper than a Lyman M-Die and in many more sizes than Lyman makes.
I don't do powder through expander dies ... so this is how you do it on a single stage press .
Gary