38-40 Crimping Issues

[rbertalotto]

I know this has been discussed a thousand times here on the forum. But the 38-40 is new to me so I'll simply add to the conversation.

The issue is this cartridge was designed for a full case of Black Powder which will limit the bullet from migrating into the case when hammered by other cartridges in a magazine tube on a lever action rifle.

When smokeless powder is used there is a large airspace under the bullet and the bullet needs a strong crimp to keep it in place. But the 38-40 uses extremely thin brass and does not share the neck tension of other types of brass.

The bullets I'm currently casting do not have crimping grooves Lyman) or the crimping groove is in the wrong place and the cartridge OAL is too great to feed properly (LEE)

I ordered the RCBS mold that should have the crimp groove in the proper location.

Here is where I stand:



First some info: www.rvbprecision.com (1873 Winchester article)

I slugged my bore .395 bore / .398 groove

I'm using a LEE seating die with a roll crimp. I loaded thirty cartriges with smokeless powder for my first range session. With five in the magazine, the last two failed to feed because the bullets had been pushed completely into the case.

Here is the issue. My bullets are dropping at .403 and the hole in the die that the bullet must go through before the die can contact the shell and crimp the bullet is only .4015.

So the die knocks the bullet into the mouth of the case before the die can do its crimping. Not good. (Although this would be fine with Black Powder as the powder itself will limit bullet travel within the case.

I need to size my bullets to .401 or use a LEE Factory Crimp Die.

I ordered a .401 sizing die for my STAR lubrisizer from Lathesmith. And I have the LEE Factory Crimp Die and a set of RCBS Cowboy Dies in 38-40 on the way.

Lots of experimenting required............

[Calamity Jake]

I shoot a 44-40 in a Uperti 1866 copy, I too use a boolit with the crimp groove in the wrong place(Saeco 200 RNFP) I load them on a Dillion 550 leaving out the crimp then use my rockchucker to roll crimp into the front drive band, have had no trouble will boolit setback in
the mag tube.

[fcvan]

Roy, I purchased a Ruger Vaquero in 38-40 a couple years ago because it also had a 40S&W cylinder. It is fun to shoot either cartridge but the bottleneck case of the 38-40 was a first for me handgun-wise.

I have two molds in .40 caliber, the Lee 145SWC and the 175TC. I size and lube with a Lyman 450 using a .401 sizing die. My Lee 38-40 dies seat and crimp with enough neck tension that I can't push the boolit into the case. I am not using a heavy roll crimp and am not crimping any tighter that I do with the 40S&W.

I have read on this site where folks have used collets to squeeze a crimp groove in their boolits or even a cannelure tool normally used on jacketed bullets. I haven't found the need to do so. I hope this is helpful. Frank

[Larry Gibson]

My bullets are dropping at .403 and the hole in the die that the bullet must go through before the die can contact the shell and crimp the bullet is only .4015.

I would consider honing the seater out to take the .403 bullet before i would size the bullet down, especially if the groove depth required the larger bullet. Just have to be careful not to hone the crimp edge off.

Larry Gibson

[runfiverun]

i think when you get your dies you'll figure it out.
i use the 38-40 boolit mold from magma and it has the crimp groove in the right place for cartridge oal.
the issue i run into was the die set and the chamber having different ideas about where the shoulder needed to be.
i had to have my sizer die milled off about 10 thousandths to make things right.
using the magma 44-40 mold for my rossi 44-40 and rcbs dies things are similar, i can't use 430 boolits in it but i can use 429. but it puts the shoulder in the right place.

the cowboy dies have a bit more room in them for larger boolits.
but weren't available when i started doing this.
the others were cut for jaxketed bullets.

[w30wcf]

"Here is the issue. My bullets are dropping at .403 and the hole in the die that the bullet must go through before the die can contact the shell and crimp the bullet is only .4015.

So the die knocks the bullet into the mouth of the case before the die can do its crimping. Not good. (Although this would be fine with Black Powder as the powder itself will limit bullet travel within the case."

I have a 44-40 with a .433" groove diameter and had the same issue. I ended up backing the seater die out to the point where the bullet could be seated to the proper depth. I then used the Lee FCD to crimp.

As was indicated, you could remove material from the bottom of the sizer die to make the neck longer (I removed .10" from the bottom of my 44-40 sizer die), or you could use a capacity load of slower burning RL7 to support the base of the bullet.

Have fun!
w30wcf

[rbertalotto]

GREAT comments folks!

I'm going to look into RL7 as I have lots of it and use it in 221FireBall and 17MKIV.

My LEE Factory Crimp Die should be here tomorrow...........We'll see!

[rintinglen]

This is one area where the Lee Factory Crimp Dies shine. The old WCF cartridges can be troublesome to load, as I can well attest. THE FCD makes crimping a snap.
I shoot the 32-20 a lot out of my Browning M-53 and S&W M&P. Using the standard crimp die, I was having a lot of problems, cases crumpled, boolits were getting dammaged: it was not working well at all. Then I got a Lee FCD and suddenly it was all blue sky and sunshine. I also use the FCD on my 44-40 loads.

[fcvan]

I decided to tinker with my 38-40 loads after reading this post. I'm shooting a Ruger Vaquero 38-40. I loaded boolits cast from a Lee 175 TC mold normally used in my 40S&W and sized to .401 with a Lyman 450 and home made lube. I loaded the cartridges with Lee 38-40 dies. As they aren't carbide I lubed the cases with a spray bottle filled with 2 ounces of Lanolin and 8 ounces of alcohol. (I heat it up and shake before I spray)

I expand the case mouths no more than is necessary to accept the boolit. I crimp the cases no more than I do for semi-auto rounds that headspace on the mouth. Try as I may I could not push the boolit deeper into the case. I fired 4 rounds and inspected the 5th and 6th rounds to see if they jumped the crimp. The only thing I could do to get the boolits to jump the crimp was squeeze the trigger. That worked so well I felt inclined to empty 50 rounds.

I got home and reloaded the box of empties. The load is about 975fps. Just to make sure today's success wasn't a fluke I intend to repeat the process tomorrow. I expect that the results will be similar but just in case I may have to try again the day after tomorrow . . . Frank