Case separation.

Discussion of BPCR loading techniques, SAFETY, Case Cleaning and Prep, Indexing, BP Choice, Primers, Wads, Compression, Drop Tubes, Vibration, Load Testing, etc.
Singleshot S.A.
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Case separation.

Post by Singleshot S.A. » Tue Jan 14, 2020 4:38 pm

Hi all,
I recently purchased some new Brass in 38/55 for re sizing to 32/40.
I have two rifles in this cal, and have resized many cases from 38/55.
I always anneal first, then take three steps to complete the sizing, and Don't usually loose many cases at all.
I then trim them roughly to length, fire form them, then trim them again.
This time I'm getting case separation. 2 out of 3 on the first firing. (Swiss 2f) So I unloaded all the remaining cases and re loaded with Wano P (no Swiss available here at the moment) only to have the same result again. I am loading a (full case) weighed 49.0 grns. With a LDPE wad for Breach seating.
Any thoughts. ?? I've never had this happen before. I'm using the same brass as always. They are separating at about 1/2 way down the case.
Should I re anneal them ??

I will go back to the old (Gaintwist) cases for now, but Don't understand what's happened.
By the way, the new Starline hold more powder than the Gaintwist, so wall thickness must be different. I also note that the Gaintwist heads are 2 - 4 thou thicker, surely that's not enough for a headspace problem in the Starline ??

If anyone has any Gaintwist cases they Don't need, I would gladly take them.

Crash Landing
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Re: Case separation.

Post by Crash Landing » Mon May 18, 2020 8:14 pm

Singleshot S.A.
The situation you are experiencing is similar to mine. I was having .32-40 case separations, breech seating with the case full of straight black powder. Both reformed Starlilne .38-55 and WW .32-40 cases were separating in the same place as yours and at about the same ratio as you are having.
Here are the steps I used that stopped .32-40 case separations:
1.Tumble clean cases before reloading. I use stainless steel pins in a cheap’o rock tumbler from Harbor Freight.
2.Trickle powder into cases through a 24 inch drop tube. Fill cases so powder is even with case mouth.
3.Use an .030 inch snug fitting card wad in case mouth, press down so wad is even with case mouth. I haven’t tried LDPE wads.
4.At first it worked best with FG or 1.5 F Swiss but as I became more proficient with this loading method, it worked with 2F also.
IMO the key is not too much powder compression. I have reloaded at the range with a single cartridge case using only a case scrapper to clean cases between shots. After well over a 100 shots the reformed Starline .32-40 case I use is still intact.
This is all breech seating, I have no idea if this will work for fixed ammo.
This basic loading method is covered in some detail in my book - The Golden Age of the American Schuetzenfest.
Crash

TexasMac
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Re: Case separation.

Post by TexasMac » Tue May 19, 2020 10:09 pm

Read this article and see if any of the condition listed that result in case separation fit.
http://www.texas-mac.com/Case_Stretchin ... ifles.html

Wayne
NRA Life (President's Council) Member, TSRA Life Member, NSSF Member
Click on http://www.texas-mac.com/index.html to my home page containing information on my Browning/Winchester BPCR book & associated articles.

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Ranch 13
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Re: Case separation.

Post by Ranch 13 » Wed May 20, 2020 6:19 am

Check the thickness of the brass at the mouth of the case. I had that happen with some starline 38-55 sized to 32-40. The guy I got the rifle and cases from said he was perplexed by it, he could load smokeless and no problems, black powder loads would seperate the cases... After I thought it was probably something he was doing with bore wiping or such, nope was just the brass was to thick at the mouth.

Brent
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Re: Case separation.

Post by Brent » Wed May 20, 2020 6:42 am

You definitely don't want to anneal them more than you have. That would only seem to make it worse.

Personally, I put no credence on compression causing stretching or case separation. I have used extreme compression to the point of the case expanding so much that it would not fit in the chamber, and got no stretching.

I have also used all types and thicknesses of wads and cookies and never had a stretching or separation problem.

However, I have carelessly failed completely remove sizing lube from my cases once, and they stretched and separated pretty readily.
I'm not from here, I just live here.

Kurt
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Re: Case separation.

Post by Kurt » Thu May 21, 2020 9:15 pm

Is there any sign that the case mouth is getting pulled into the throat from being too long?
I formed some .44 - 3.25 Bell basic brass for the .44-90 bn and breach seated the bullets for blowing the shoulders out but I trimmed them .010" too long that pulled the neck into the throat and it pulled the first 3 necks.You wouldn't thing a case load of powder would do this like a bullet would loaded in the case neck.
"Complaining about a problem without posing a solution is called whining."
Teddy Roosevelt.

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