The Firing Line Forums

Go Back   The Firing Line Forums > The Skunkworks > Handloading, Reloading, and Bullet Casting

Reply
 
Thread Tools Search this Thread
Old September 22, 2010, 11:05 AM   #1
zxcvbob
Senior Member
 
Join Date: December 20, 2007
Location: S.E. Minnesota
Posts: 4,720
Need some help customizing QuickLOAD

I've been using QL for several years and love it. But now I'm trying to develop loads for .38 S&W (a.k.a .38 Colt N.P.) and I'm having some problems; there's obviously something wrong in the cartridge database.

I have some actual Starline .38SW brass, and some .38 Special brass that's cut down to .775". The Special brass fits loose in the chambers because it's a slightly smaller diameter cartridge. So how come if I plug in the same powder, bullet, and length numbers in for .38 Special and .38 S&W, the .38SW comes up with a significantly higher pressure instead of slightly lower? I think the actual problem might be with the .38 Special data rather than the .38 S&W, because I've seen strange results when comparing .38 Special and .357 Magnum before. Also my .38 Special loads don't really match published load data very well; I put in their numbers and get much lower pressures and velocity.

So, how do I measure the water capacity myself, assuming that's the measurement that's off? I have an idea: put 10 fired cases (so I get an average) on a digital scale and zero it, then fill each one to the top with distilled water with a drop of soap in it, and divide the weight by 10. Or is there another measurement that could be throwing things off?
__________________
"Everything they do is so dramatic and flamboyant. It just makes me want to set myself on fire!" —Lucille Bluth
zxcvbob is offline  
Old September 22, 2010, 11:38 AM   #2
Unclenick
Staff
 
Join Date: March 4, 2005
Location: Ohio
Posts: 21,017
That's correct. Just be sure there is no meniscus, positive or negative. For rounds that fire below 30,000 psi do this with sized cases, and use fired case capacity for those running above that peak pressure. If you want, you can download the Excel file I made for water weighing from my file repository. It adds compensation for change in water density with temperature, but the difference is pretty small.

One problem with all brass is that SAAMI and the CIP only spec the outside dimensions of the brass. The internal case head dimensions and the the like are up to the manufacturer, so even though the QuickLOAD data shows suspiciously low case water capacity for the .38 S&W it could be correct for some make somewhere, and the program usually has a worst case default where the author knows what that is. Notice, for example, he has separate cases for .300 Win. Mag. for Winchester, Remington, Federal, and Norma because the cases are different enough to warrant that (and I suspect the author owns that chambering and has seen it).
__________________
Gunsite Orange Hat Family Member
CMP Certified GSM Master Instructor
NRA Certified Rifle Instructor
NRA Benefactor Member and Golden Eagle
Unclenick is offline  
Old September 22, 2010, 11:44 AM   #3
zxcvbob
Senior Member
 
Join Date: December 20, 2007
Location: S.E. Minnesota
Posts: 4,720
Quote:
For rounds that fire below 30,000 psi do this with sized cases, and use fired case capacity for those above.
That brings up another point about this project. When I'm using cut-down .38 Special brass and only loading to about 12500 psi, it's going to expand and spring back (mostly) every time rather than expand and stay that way. So I should probably make a full length expander and use it once as part of my case-forming, so the brass won't work-harden and crack so fast after a few firings...
__________________
"Everything they do is so dramatic and flamboyant. It just makes me want to set myself on fire!" —Lucille Bluth
zxcvbob is offline  
Old September 22, 2010, 01:30 PM   #4
Unclenick
Staff
 
Join Date: March 4, 2005
Location: Ohio
Posts: 21,017
Assuming you have correct dies for resizing .38 S&W, if your loads are too light to provide permanent expansion of the brass, just don't resize it. Decap, flare and seat and crimp. That's it. If you eventually find the bullet slipping into the case mouth, then apply the .38 S&W sizing die.
__________________
Gunsite Orange Hat Family Member
CMP Certified GSM Master Instructor
NRA Certified Rifle Instructor
NRA Benefactor Member and Golden Eagle
Unclenick is offline  
Old September 23, 2010, 12:42 AM   #5
Clark
Senior Member
 
Join Date: December 4, 1999
Location: WA, the ever blue state
Posts: 4,678
My grandfather had an Iver Johnson 38 S&W breaktop 5 shot revolver in the Alaskan Gold Rush, and it is a family heirloom worth $50. But it interested me, so I bought a whole bunch of them at the guns show and overloaded them until I stretched the latch.

My father was chief engineer over 150 engineers and draftsmen for 40 years.
He designed guns and vehicles.
He is REALLY smart.
I showed him an antique break top revolver I screwed up [Using ~ 38 Super +P type loading with jacketed 158 gr bullets] and said there was too much pressure.
My father snapped at me, "That is not from pressure. That is from bullet friction and recoil acceleration on the some of the barrel mass."

I did not get it. I had to think and think about what he said.
After 2 days I could start to see it.

So now when I shoot old 38 S&W break tops, I use wimpy loads with little recoil and soft lead bullets.
Clark is offline  
Old September 23, 2010, 09:58 AM   #6
zxcvbob
Senior Member
 
Join Date: December 20, 2007
Location: S.E. Minnesota
Posts: 4,720
I'm trying to work up loads for a Colt Police Positive and a Webley top-break. Ultimately I want to give a box of ammo to a friend who has a S&W top-break. I'm starting with soft lead bullets for everything except maybe I'll use hard lead in the Colt and Webley (but not the S&W.) I'm not looking for a barn-burner load, just something accurate, not too filthy, and an honest 700 to 750 fps with a 150-ish grain bullet.

Since the Colt has a solid frame, j-bullets would probably be OK, but it was made in 1919 so I'm assuming the frame is soft steel and I don't want to abuse it. And I don't want to dust off my brain cells that have the "modulus of elasticity" stuff.

Quote:
Assuming you have correct dies for resizing .38 S&W
That's a big assumption. I'm trying to get by with 9mm Luger dies, which should only size the top half of the case. I also have 9mm Mak dies that might work better for seating and crimping. I will buy .38SW dies if I need to, but I want to see what I can do with what I have already.
__________________
"Everything they do is so dramatic and flamboyant. It just makes me want to set myself on fire!" —Lucille Bluth
zxcvbob is offline  
Old September 23, 2010, 11:20 AM   #7
Jim Watson
Senior Member
 
Join Date: October 25, 2001
Location: Alabama
Posts: 18,483
There was a thread here a while back about the difficulty of running Quick Load for pistol and straight wall rifle cartridges. I think I would go with Lyman.
Jim Watson is online now  
Old September 23, 2010, 05:30 PM   #8
Unclenick
Staff
 
Join Date: March 4, 2005
Location: Ohio
Posts: 21,017
QuickLOAD does do better with bottleneck rifle cases, but comes very close on a lot of the .45 ACP loads I use. If you have actual velocity data to work with, you can correct the errors.

Zxcvbob,

To address your original question, no doubt, when the .38 Special Case and the .38 S&W case are given bullets seated to the same COL, it shows the .38 Special having a couple more grains of usable water capacity under the bullet. That may be part of the original case design? I don't know, but if you cut down .38 Special cases, there should be no difference in reality.
__________________
Gunsite Orange Hat Family Member
CMP Certified GSM Master Instructor
NRA Certified Rifle Instructor
NRA Benefactor Member and Golden Eagle
Unclenick is offline  
Old September 23, 2010, 09:11 PM   #9
SL1
Senior Member
 
Join Date: November 8, 2007
Posts: 2,001
Zxcvbob,

Looking at the calculations, I see several things:

1. The change in seating depth for the .38 Special to make it the same length as the .38 S&W does not make the remaining useable case capacities identical. The Special remains larger, for reasons that aren't clear. Further reducing the COL to match the Special available case capacity to the S&W case makes the Special pressure slightly higher than the S&W pressure. So, actually measuring your case capacities will be essential for making any more progress.

2. There are other differences, including the bore cross sectional area and the weighting factor. The weighting factor doesn't seem to make much difference (in this case) and the bore area difference makes much less difference than the case capacity.

SL1
SL1 is offline  
Old September 24, 2010, 07:47 AM   #10
Unclenick
Staff
 
Join Date: March 4, 2005
Location: Ohio
Posts: 21,017
Zxcvbob,

One on other quick check you can do: if you have some actual commercial .38 S&W brass and some of your cut-to-same-length .38 Special cases, just weigh the two. If the .38 S&W brass actually has a couple of grains less water capacity due to thicker brass, it should weigh about 17 grains more at the same length.
__________________
Gunsite Orange Hat Family Member
CMP Certified GSM Master Instructor
NRA Certified Rifle Instructor
NRA Benefactor Member and Golden Eagle
Unclenick is offline  
Reply

Tags
quickload

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 05:02 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
This site and contents, including all posts, Copyright © 1998-2021 S.W.A.T. Magazine
Copyright Complaints: Please direct DMCA Takedown Notices to the registered agent: thefiringline.com
Page generated in 0.05740 seconds with 10 queries