OAL for 158 grain SWC?

ahanes · February 19, 2010, 05:52 PM

Guys, ran into a little confusion trying to work up a new load for my .38 Special. I cast up some 158 grain tumble lube SWC's and went to my Lee's Modern Reloading Second Edition, but the data shows a minimum OAL of 1.55 when using 4.1 grains of WIN231. This leaves the bullet barely in the case and won't even fully chamber in my Smith Model 15, just doesn't seem right.

Looking around on the internet for additional data, the OAL is all over the place, though a few others also show 1.55 as the correct OAL. Just eyeballing, 1.48 looks like a good depth, but I'm wondering if I'm going to raise my pressure too much. To add to my confusion, the +P load is 4.5-4.7 grains of WIN231 with an OAL of 1.481...

Bottom line, do you think 4.1 grains of WIN231 at t1.48 OAL is safe (I know, I need to get a chrono)?

hornady · February 19, 2010, 06:08 PM

My Lyman cast bullet book gives a OAL of 1.460 for there 158Grain SWC and the charge with Win, 231 is 3.5 to a max of 4.7

**Unclenick** · February 19, 2010, 06:20 PM

The reason the Internet COL's are all over the map is the design of the SWC noses are all over the map. With the tumble lube bullets, I just use the top-most bullet lube groove—the one nearest the nose—to crimp into. As long as the OAL doesn't exceed the SAAMI max (1.55"), you are good to go.

Clark · February 19, 2010, 07:39 PM

I have blown up a half dozen 38 specials in experimental work ups.

Do not work up loads, just follow the cook book load books.

What would you be looking for in the work up?
The first crack in the cylinder?
With AA#5, the is the first thing you will see, except small Aluminum frames may bend first, but in strong frames, the cylinder goes first.

Typically the cylinder breaks into two or three pieces and half the time the top strap breaks. The cylinder pieces leave at such a velocity that they put holes in wood and sheet metal.

Working up loads in 357 mag works better, as there is some pressure sign on the brass:
http://groups.google.com/group/rec.g...02ce69fa01e631

ahanes · February 19, 2010, 08:22 PM

Not really "working up a load" in the traditional sense, just my first loads with the newly cast bullets. I tried to follow the cookbooks, but their OAL spec didn't work.

I'll try the 1.48 OAL and look for any overpressure signs, but from the replies I think it'll be good.

Thanks to all.

zxcvbob · February 19, 2010, 08:41 PM

That bullet loaded to 1.48" will give you less than 15000 psi chamber pressure with 4.1 grains of 231. Muzzle velocity will be about 800 fps from a 4" model 15. 4.5 grains will get you to almost 17000 psi and 875 fps (still not "+P" by anybody's definition, but getting close.) HTH

February 19, 2010, 05:52 PM	#1
ahanes Junior Member Join Date: June 25, 2008 Posts: 9	OAL for 158 grain SWC? Guys, ran into a little confusion trying to work up a new load for my .38 Special. I cast up some 158 grain tumble lube SWC's and went to my Lee's Modern Reloading Second Edition, but the data shows a minimum OAL of 1.55 when using 4.1 grains of WIN231. This leaves the bullet barely in the case and won't even fully chamber in my Smith Model 15, just doesn't seem right. Looking around on the internet for additional data, the OAL is all over the place, though a few others also show 1.55 as the correct OAL. Just eyeballing, 1.48 looks like a good depth, but I'm wondering if I'm going to raise my pressure too much. To add to my confusion, the +P load is 4.5-4.7 grains of WIN231 with an OAL of 1.481... Bottom line, do you think 4.1 grains of WIN231 at t1.48 OAL is safe (I know, I need to get a chrono)?

February 19, 2010, 06:20 PM	#3
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,061	The reason the Internet COL's are all over the map is the design of the SWC noses are all over the map. With the tumble lube bullets, I just use the top-most bullet lube groove—the one nearest the nose—to crimp into. As long as the OAL doesn't exceed the SAAMI max (1.55"), you are good to go. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

February 19, 2010, 08:41 PM	#6
zxcvbob Senior Member Join Date: December 20, 2007 Location: S.E. Minnesota Posts: 4,720	That bullet loaded to 1.48" will give you less than 15000 psi chamber pressure with 4.1 grains of 231. Muzzle velocity will be about 800 fps from a 4" model 15. 4.5 grains will get you to almost 17000 psi and 875 fps (still not "+P" by anybody's definition, but getting close.) HTH __________________ "Everything they do is so dramatic and flamboyant. It just makes me want to set myself on fire!" —Lucille Bluth

February 19, 2010, 06:08 PM	#2
hornady Senior Member Join Date: April 6, 2009 Location: SWPA Posts: 428	My Lyman cast bullet book gives a OAL of 1.460 for there 158Grain SWC and the charge with Win, 231 is 3.5 to a max of 4.7

February 19, 2010, 07:39 PM	#4
Clark Senior Member Join Date: December 4, 1999 Location: WA, the ever blue state Posts: 4,678	I have blown up a half dozen 38 specials in experimental work ups. Do not work up loads, just follow the cook book load books. What would you be looking for in the work up? The first crack in the cylinder? With AA#5, the is the first thing you will see, except small Aluminum frames may bend first, but in strong frames, the cylinder goes first. Typically the cylinder breaks into two or three pieces and half the time the top strap breaks. The cylinder pieces leave at such a velocity that they put holes in wood and sheet metal. Working up loads in 357 mag works better, as there is some pressure sign on the brass: http://groups.google.com/group/rec.g...02ce69fa01e631

February 19, 2010, 08:22 PM	#5
ahanes Junior Member Join Date: June 25, 2008 Posts: 9	Not really "working up a load" in the traditional sense, just my first loads with the newly cast bullets. I tried to follow the cookbooks, but their OAL spec didn't work. I'll try the 1.48 OAL and look for any overpressure signs, but from the replies I think it'll be good. Thanks to all.