Are you using oversize expander plugs?

[tacotime]

Having a heck of a leading problem with swaged .358 Speer bullets in .38 SPL at mid and full power non +P loads in 4 different revolvers. Some loaded and pulled bullets measure .357 or slightly less. Apparently compressed when seating but not shaved.

I expanded cases with Lee, the RCBS Cowboy expander and Lyman M 38P. The RCBS were a little less compressed but still leading up (3.1 to 3.5 Bullseye). I expanded also with a and these were slightly worse. These expander plugs are .3552 to .356. The RCBS bullets hang up when dropped in the throats. Some of the others fall through.

Do I need a .357 or .358 custom expander plug?

Thanks.

[uscra112]

If you are shooting cast, absolutely. I have a number of .30 and .35 caliber expander plugs, some bought, several made by me. Brass hardness, neck wall thickness, even the amount the neck is shrunk by the sizer die, make me use one or another to get the right case mouth diameter for proper seating of boolits.

[bigted]

look on buffalo arms web site. they sell oversize expanders for what you need.

[EDG]

I use them and they improved accuracy in my rifles.

[btroj]

A 38 special shouldn't need an oversized expander. The case walls are thin enough that they shouldn't swage down even a soft bullet.
Over expanding reduces neck tension which can lead to poor accuracy. Neck tension is what holds the bullet in place, not a crimp.

I would be looking elsewhere for the problem.

[tacotime]

Thanks for the Buffalo link, that is what I wanted to find...

It does appear that the bullet bases are being compressed to .357 or slightly less.

I think I am going to try a larger expander... for these .358 bullets (so far using a .356 expander), should going to .357 be the choice, or to .358? Not sure what the spring back factor may be for main brand .38 cases.

If I used a .358 plug would the case be expected to spring back to .357 and be the correct neck tension?

Would a .359 expander for sure be too large?

[waksupi]

Had that problem with a rifle. Called RCBS and explained the problem, they sent a larger sizer, no cost.

[runfiverun]

the spring back is gonna vary depending on the anneal of the brass.
I'm with btroj I'd re-look over the set-up, it might be the sizer or a fcd or something else.
measuring out from a fired case through the process should reveal the culprit.
the spud you expand with might be it but if you need to re-expand a sized case I'd take a look at the sizing die especially if it's a newer nitride ringed one.

[tacotime]

So are you saying maybe the carbide sizer is too small?

I've got two others to try besides Lee - Lyman and RCBS, all carbide.

I'm not sure what you meant by re-expand a sized case? You mean even running it through the expanding die at all after sizing? Like I could skip expanding and bell the case only like with a universal expander working only the case mouth?

RCBS has an expander plug listed as a true .358 but it is for rifle and does not fit the pistol die. A guy suggested it would work, but you have to have the rifle die, and I am not sure the plug would reach down far enough to get into the .38 SPL case, since the die is a longer rifle die.

Buffalo dies are sold out... except a straight .359 expander plug.

Note - the FCD has not been used on these loads.

Thanks.

[runfiverun]

the carbide rings are a circle designed to size the whole case.[only smaller]
if you look at the old steel dies they are actually tapered and generally don't size as much, and will allow you to partial length size to not size down as much.
this lets the flair spud do it's job of flaring the case mouth without it having to act as an expander.
measure from a fired case inside and out then size one and see what it's doing.
you might be able to polish out the carbide ring for a better working solution [you wouldn't be the first to do this]
this one size ring is why redding has come out with a dual ring set-up where the base one is larger than the case mouth ring to maintain the case taper.

[tacotime]

Federal case:
Unsized .378
Lee sized only .373 (Expander is .356)
RCBS sized only .372 (Expander is .3560)
Lyman sized only .371 (Expander is .3554)

Lee dies loaded the original fouling rounds.

Where does that leave me?

[Char-Gar]

Expanders on current dies measure .356 for use with .357 jacketed bullets. They work fine with hard alloy bullet, but go to soft alloy or swaged bullets and you get what you discovered.

Back in the day, Lyman 310 expanders for 38 Special and .357 Magnum measured .358 and .357 respectively. Finding one of these on Ebay is not chore, but you will need a threaded adapter for use in your press.

For my cast bullets, I use a .358 expander. There is enough spring back for a good fit of a .358 bullet with a suitable crimp.

[TXGunNut]

If Buffalo is sold out just order what you want, just takes a week or so. AFAIK the RCBS expanders work in the Lyman M-type dies. That said, I'll join the "re-check everything" chorus, something's not adding up.

[Char-Gar]

I tend to collect 38/357 dies and they do vary quite a bit with make and vintage. I do not like current carbide dies at all for they reduce the case to much and overwork the brass. I use vintage RCBS steel dies for 38 Special, 357 Magnum, 44 Special, 44 Magnum, 45 Colt, 45 ACP and AR.

For fun, here is a picture of some RCBS expanders of various vintages. Left to right they are an older .357, a more recent .356, a vintage .357 modified by me to have a deeper reach for full wadcutter bullets, a special long .3585 for use with hollow base wadcutters in wadcutter brass.

Next pic is three Lyman expanders, also left to right, a 310 .357, a 310 .358 and a current M type .356.

You might say I am a true believer in matching bullets of various hardness and styles with the proper expander for best results.

[Doc Highwall]

This is the major reason that cast bullets get a bad rap for leading along with bad accuracy, 99.99% of reloading dies are made for jacketed bullet diameters and jacketed bullet hardness. The lead bullets that we shoot need to be at least .001" - .002" larger in order to prevent gas cutting and the case neck expanders also need to be larger in order to accommodate the larger cast bullet diameters especially with soft lead bullets. If you are shooting a very hard alloy that has been water dropped out of a revolver with full power loads a tight bullet grip will be needed and your conventional reloading dies should suffice.

[Char-Gar]

I find it somewhat humorous that folks think of .357 - .358 expanders as being "oversized". When it comes to cast bullets the factory .356 expanders are "undersized".

As stated previously, the .356 works just fine if you have granite hard bullets, but I don't favor such bullet tho many do.

[runfiverun]

I'd be looking at buffalo bore to order the larger diameter.
lapping out a sizer ring and not actually using an expander, just as a flair.
having buckshot make me a new expander spud.
call rcbs and ask them about their expander for their cowboy dies.

that's about all the options I can think of right now.

[tacotime]

I ordered the .357 and .358 from Buffalo...

RCBS Cowboy for .38 is .356 with a larger step at the end similar to the M die, and they do not sell larger ones for .38. The standard .38 plug is also .356 presumably with a smaller step. So I am not sure they were all that serious about a plug for lead shooters. Seems like they would have offered larger plugs as an option. I really don't get that from an outfit involved in cast bullet sports.

How tough is it to lapp out a carbide sizer? And how? I've got a spare I could try...

[Marvin S]

I doubt you will be able to do anything with the carbide ring besides stare at it and wish it was bigger. I usually buy LEE dies as it is so simple for me to turn a stepped expander plug to any size I want. The LEE is just a floating plug.
A tool post grinder with the correct combination of mounted points is what it would take to open up the carbide ring.

[cbrick]

Ordering both expanders may have been a wise choice. When they arrive start with the .358 and check bullet pull & seating effort. You'll need to keep in mind that the older (as in more times fired) the brass the more it will be work hardened and thus less spring back/neck tension. If this appears to be the case then switch to the .357 spud and/or new brass. Annealing is also an option.

Rick