Old RCBS .38 Special Dies are different

[Pistolero]

A month or two back Char-Gar mentioned something in a thread on another board about 'old style
RCBS .38 Spl dies' having a noticeable bottleneck shape, and different than our current dies,
especially the carbide type dies which have a sizing ring so are pretty much cylindrical.

I was curious, and trying to learn about how to make accurate .38 Spl ammo for my Model 14s,
so I found a set of old looking (green and white cardboard box) dies with date codes which put
them in the late 59-60 time period, and purchased them. I sat down and started measuring
brass. The first thing is that you can actually SEE a ring at the neck of the case that is sized
noticeably tighter than the rest of the case. Measuring this shows it is the first 0.25 of the case,
and after FL sizing, this portion is .3718 OD. Comparing to a case sized in recent Hornady
dies (which have a TiN sizing ring, equivalent to a carbide die set, pretty much) I found that
the OD at the neck was .3745, so the old dies size the neck down an additional almost .003".
The body portion of the modern Hornady dies is pretty much the same, at .3747". The old
RCBS steel dies leave the body at .3777 OD below the .25 long ring at the neck. This is .003 larger
and seems like this may keep the cases centered better in the cylinders, we will see in testing.

The old RCBS expander leaves the neck at .3755 OD and the new Hornady dies leave the OD
of the neck at .3748, which is very nearly unchanged from the dimension after FL sizing. This
is good for case life, no doubt and the old dies work the neck a lot more - might need to anneal
necks with the old dies to keep case life long. Again, we will see. In both cases, using pin
gauges, the final ID was .355. Interesting.

Well, just verifying that Char-Gar is right (no surprise there) and old RCBS steel dies are quite
different than current "carbide" type .38 Spl dies. I will be doing some testing to see which
dies produce the most accurate ammo, if I can tell a difference.

Just a bit of historic triva about reloading that I stumbled across in my quest for accuracy
with the .38 Spl. Knowing that at one time there were huge numbers of 2700 shooters
working to discover the best way to make holes appear in the X ring with .38 Spl ammo
and mostly Model 14s or K-38s, by the original name.

 

[358156hp]

I'll have to look up the numbers again, but I sized and measured some 357 mag cases that I sized in an old Pacific Durachrome sizing die and reached similar results. Another part that was really evident was that the cases didn't show the usual mark near the bottom where the sizing ring on the carbide dies stopped. Instead I found a more gradual taper into the web area.

 

[Brad]

I can't help,but think a big advantage of the old steel dies is the ability to lap the neck area to reduce the over sizing in the area. You can tailor the sizer to the bullet size you use. Not gonna do that with a carbide type sizer.
I don't like steel sizers for most pistol cases because they require lube and I don't want to lube cases to load on my Dillon.
Might need to change my thinking on that a bit.

 

[358156hp]

Long, long ago, I had a machinist friend turn down the expander button for a Durachrome die down to Skeeters specs. I need to find that and do an old-fashioned comparison.

 

[Pistolero]

Thinking about this some more, it would seem that partial sizing (neck sizing, if you will) with
the new Hornady dies may be a useful thing to try. Leave the rear of the case fat to center in
the chamber, but make the neck grab the boolit well (hey, do we use bullet or boolit here?)
and not work the neck so much as the old RCBS dies.

 

[Brad]

Sorta like Rick does with 44 mag? Should work well enough. Makes complete sense to me.

 

[Brad]

Hey Bill, I recognize that firing line in your avatar. I spent my share of time laying there too.

 

[Rick]

I've got an old set of 38/357 dies in a cardboard box just as Pistolero described. Haven't used them in years (make that decades) but i'll have to do some measuring and see what I come up with. I only stopped using them so I could stop lubing cases but this could prove quite interesting.

 

[Rick]

Thinking about this some more, it would seem that partial sizing (neck sizing, if you will) with
the new Hornady dies may be a useful thing to try. Leave the rear of the case fat to center in
the chamber, but make the neck grab the boolit well (hey, do we use bullet or boolit here?)
and not work the neck so much as the old RCBS dies.

Bullet will do nicely thank you.

I neck size all my 357 brass, never size the full length of the case. Size down as far the BULLET sits in the case.

 

[Brad]

Bullet please.
I have read about neck sizing pistol cases before but have only done it for 45 Colt. That might be because my Marlin and Riger both have huge chambers and after 10 loads or so I get splits damn near the length of the case.

 

[Pistolero]

Well, Brad, my avatar photo was taken on the line at ENGC during a Swiss match. Lots of good times
there with Dr. Rick and his friends. Eyes are so bad now that I won't be able to compete
usefully with irons until I get the eyes fixed, if then. Working on that, and soon.

But - the first time I went 'old school' was for the .45 Colt, bought old steel RCBS dies because
Brian Pearce of Handloader had mentioned that the old dies had a notable taper, centering
the rear of the case in the chambers better, especially with older guns with notably tapered
chambers. It appears that the actual chambers for the older .45 Colts were tapered, but today
the SAAMI cartridge is different, it has been converted to a straight case, and the rear of the case rattles
in the chambers of older guns. This is part of the reason that I perked up when Charles
mentioned the old RCBS .38 Spl dies. Second time for me.

I will definitely try neck sizing .38 Spl and .357 in the future.

And a tip of the hat to Charles for passing on this tidbit, something I would have
been very unlikely to stumble across on my own. Together we are much more
capable than separately, online idea exchanges are wonderful for learning, and I
am still learning all the time.

Bill

 

[Charles Graff]

Good to see Pistolero/Bill here and even better to know he learned something.

I went back to the old steel dies after dealing with carbide sized brass in large 45 Colt charge holes. The brass tended to rattle around and lay at the bottom of the hole. I tried just neck sizing the brass, but while this worked for the handgun in which it was fired, ammo thus produced would not interchange between my several 45 Colt handguns I own, even of the same make.

I picked up an old RCBS steel die and got out the micrometer and found out what a difference there was. The specs produced were spot on with factory ammo. After than I went back and acquired older steel dies for the 38 Special, 357 Magnum, 44 Special and 44 Magnum. I have a steel dies for the 45 ACP, but it produces cases the exact same size as my carbide die, so no gain there.

Now, just how much will these dies improve accuracy? I have no idea and it would require a more scientific mind than mine to do the controlled testing to find out. But on a theoretical basis, I think the old steel die sized cases offer several advantages.

1. The cases are not as loose in the charge holes and thereby the bullet had a better chance to enter the throat straight and not canted.

2. The less you work your brass, the longer it lives.

3. Ammo thus produced, is just plain cooler than carbide die produced ammo.

4. Retro is good!

Addendum: I have old Pacific and Lyman 38 Special sizing dies and they produced the same two diameter sized case of the same specs as the older RCBS.

I have no experience with the new RCBS Cowboys dies, but from what I hear they are a throwback to the earlier dies of better specs when cast bullets were king of the hill.

 

[Charles Graff]

I might add a word on expanders for the 38 Special round. Current production RCBS and other makes are .356 for jacketed bullets. These work just fine for hard cast bullets, but for softer bullets there is a risk of deforming .358 - .359 bullets. Old RCBS dies came with .357 expanders. The Lyman 310 expanders were .358 for the 38 Special and .357 for the .357 Magnum rounds.

Here are some RCBS expanders that I have. They are left to right;

1. Older .357 expander
2. Newer .356 expander
3. Older .357 expander I modified in my shop for a deeper reach to expand for solid base wadcutters
4. Special long .3585 expander, for HBWCs in wadcutter brass. RCBS no longer offers these for sale.

The second pic are some Lyman expanders, the modern .356 and 310 expanders in .357 and .358

 

[Charles Graff]

Here is another tidbit of trivia regarding dating RCBS dies. The current production dies have the last two digits of the year stamped on top of the sizing die such as 98 for 1998.

RCBS started producing dies in 1949 and they used a letter code. A was 1949, B was 1950, C was 1951 and so forth. They didn't finish the alphabet before they went to the two numerical digit system.

 

[Brad]

Now that is something I did not know.
We see all these letters and numbers stamped on stuff and never know why.

 

[358156hp]

What's old is new again. I've been working a lot with Doug Elliot (Floodgate) lately, gaining (a lot) of knowledge and information on Ideal moulds and reloading equipment. The old stuff is some seriously cool stuff! There is a lot of very useful, very pertinent information in the past, waiting to be rediscovered. So much knowledge got lost, or at least seriously misplaced, with the advent of "modern" reloading/handloading. It did make some areas easier and more productive, but there are a lot of things that never should have been "set aside".

 

[Charles Graff]

In previous generations, thing moved much slower and the change between generations was much less. Folks tended to hold on to the wisdom of previous generations. Today we are living life with warp speed change and the thinking of many young people is that anything before their time has no value to them. This is not true in hand loading or in any area of life and living.