Unable to crimp 38-40 cases after trimming them to trim to length

mrappe · April 16, 2018, 03:30 PM

I have been loading 38-40 for 22 years using a Redding FL die set. I was shooting an original Winchester 1873 with a 24" barrel in that caliber up until a 1 1/2 years ago when I bought a Uberti 73 from Taylors with a 20" barrel in 38-40. I found that when I when I loaded 10 rnds (the max that we ever load for a stage) into it some of the bullets would get pushed back into the case. This never happened with my older gun which had a longer mag and an old spring so I realized that the rnds needed a firmer crimp and finally started seating the bullets with the Redding die and crimping them with a Lee Factory Crimp Die. This was working and I bought some new Starline brass and measured it. It was way longer than the max length so I trimmed it to the recommended length of 1.295" and loaded it but I saw that the crimp was not enough either with the Lee die or the Redding built in roll crimp. Under pressure the bullets could get pushed into the case. I measured my old brass and found that it was around 1.32" to 1.34" in length and over the published max length of 1.305". I have not measured or trimmed the cases in a long time and did not have any problems chambrering them in either gun. The problem seems to be that when I trimmed the new cases to the published spec I cannot get a good crimp on them due to the length of the brass even if I set the dies down to where they touch the shell holder at its peak. Someone said at my club that I should shorten the die but I don't have a lathe to do that so I am trying if all of the brands of the dies are going to have the same problem. It seems like the dies would be made so that you could roll crimp even when the brass is trimmed to the trim to length.

thanks,

Mike

44 Dave · April 16, 2018, 03:50 PM

I load .44 WCF, another fussy round.
What bullet are you using,does it have a crimp groove?
Have you shortened the magazine spring?
I had a die shortened , they are hard stuff it took a tool post grinder on the lathe.

Hawg · April 16, 2018, 07:24 PM

38-40 case length is 1.305.

G.O. West · April 16, 2018, 08:48 PM

You may be able to remove a touch of the top surface of the shell holder, by hand, using a grinding wheel. Take care to keep it square. I have done this with good results.

fourbore · April 17, 2018, 07:35 AM

It wont due any harm to use a bench grinder on the crimp die. First :

I am curious, have you measured the case length on new once fired factory ammo? You might be in for a surprise. if not, at least it would be a sanity test. Cause something dont sound quite right here. BOTH - the new brass and the dies - I suspect pilot error.

mehavey · April 17, 2018, 06:14 PM

As mentioned above, SAAMI length is 1.305MAX - 1.295MIN (not necessarily the recommended overall length)

Still... I'm having a hard time seeing a standard RCBS standard roll crimp die being unable to accommodate that.
What bullet are you using?

eastbank · April 19, 2018, 06:30 PM

I had a 45-70 seat-crimp die shortened to use on my 1876 45-60 by a local gunsmith for 10.00, a lot cheaper than a set of 45-60 dies. I would have that done on your seat-crimp die.

kraigwy · April 20, 2018, 11:12 AM

Simple fix, sick your crimping die in a lathe and cut off a few thousands from the base.

I've dont that to many of 357 crimping dies people mistakenly bought to load 38s.

Cut it as short as you need it. You can always screw the die out a little if need be to crimp longer cases.

April 16, 2018, 03:30 PM	#1
mrappe Senior Member Join Date: January 29, 2009 Location: Texas Posts: 244	Unable to crimp 38-40 cases after trimming them to trim to length I have been loading 38-40 for 22 years using a Redding FL die set. I was shooting an original Winchester 1873 with a 24" barrel in that caliber up until a 1 1/2 years ago when I bought a Uberti 73 from Taylors with a 20" barrel in 38-40. I found that when I when I loaded 10 rnds (the max that we ever load for a stage) into it some of the bullets would get pushed back into the case. This never happened with my older gun which had a longer mag and an old spring so I realized that the rnds needed a firmer crimp and finally started seating the bullets with the Redding die and crimping them with a Lee Factory Crimp Die. This was working and I bought some new Starline brass and measured it. It was way longer than the max length so I trimmed it to the recommended length of 1.295" and loaded it but I saw that the crimp was not enough either with the Lee die or the Redding built in roll crimp. Under pressure the bullets could get pushed into the case. I measured my old brass and found that it was around 1.32" to 1.34" in length and over the published max length of 1.305". I have not measured or trimmed the cases in a long time and did not have any problems chambrering them in either gun. The problem seems to be that when I trimmed the new cases to the published spec I cannot get a good crimp on them due to the length of the brass even if I set the dies down to where they touch the shell holder at its peak. Someone said at my club that I should shorten the die but I don't have a lathe to do that so I am trying if all of the brands of the dies are going to have the same problem. It seems like the dies would be made so that you could roll crimp even when the brass is trimmed to the trim to length. thanks, Mike __________________ God is fluxing me which is good but it is not fun.

April 20, 2018, 11:12 AM	#8
kraigwy Senior Member Join Date: June 16, 2008 Location: Wyoming Posts: 10,950	Simple fix, sick your crimping die in a lathe and cut off a few thousands from the base. I've dont that to many of 357 crimping dies people mistakenly bought to load 38s. Cut it as short as you need it. You can always screw the die out a little if need be to crimp longer cases. __________________ Kraig Stuart CPT USAR Ret USAMU Sniper School Oct '78 Distinguished Rifle Badge 1071

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

April 16, 2018, 03:50 PM	#2
44 Dave Senior Member Join Date: February 24, 2013 Posts: 431	I load .44 WCF, another fussy round. What bullet are you using,does it have a crimp groove? Have you shortened the magazine spring? I had a die shortened , they are hard stuff it took a tool post grinder on the lathe.

April 16, 2018, 07:24 PM	#3
Hawg Senior Member Join Date: September 8, 2007 Location: Mississippi Posts: 14,670	38-40 case length is 1.305.

April 16, 2018, 08:48 PM	#4
G.O. West Member Join Date: January 4, 2018 Location: British Columbia Posts: 25	You may be able to remove a touch of the top surface of the shell holder, by hand, using a grinding wheel. Take care to keep it square. I have done this with good results.

April 17, 2018, 07:35 AM	#5
fourbore Senior Member Join Date: August 22, 2015 Location: new england Posts: 888	It wont due any harm to use a bench grinder on the crimp die. First : I am curious, have you measured the case length on new once fired factory ammo? You might be in for a surprise. if not, at least it would be a sanity test. Cause something dont sound quite right here. BOTH - the new brass and the dies - I suspect pilot error.

April 17, 2018, 06:14 PM	#6
mehavey Senior Member Join Date: June 17, 2010 Location: Virginia Posts: 4,928	As mentioned above, SAAMI length is 1.305MAX - 1.295MIN (not necessarily the recommended overall length) Still... I'm having a hard time seeing a standard RCBS standard roll crimp die being unable to accommodate that. What bullet are you using?

April 19, 2018, 06:30 PM	#7
eastbank Senior Member Join Date: February 7, 2008 Location: pa. Posts: 1,972	I had a 45-70 seat-crimp die shortened to use on my 1876 45-60 by a local gunsmith for 10.00, a lot cheaper than a set of 45-60 dies. I would have that done on your seat-crimp die.