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slimjim Super Member
Joined: May 16, 2009 Posts: 8314 Location: Fort Worth TX
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Posted: Sun Jan 03, 2010 10:25 pm Post subject: Any suggestions for why this case failed? |
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I've had a life long project to return a 1868 Remington Rolling Block back to working order. It has been rebarreled with a Numrich 45-70. I'm shooting 405gr Laser Cast bullets with 40gr of Varget (minimum load recommended by Hodgdon) and Winchester Brass. This load has lower pressure than the black powder loads I've check on. I test fired the rifle last month with 3 shots. Went to the range today to check out the new trigger spring and see how accurate the barrel is. Temp was 40 degrees with a breeze out of the North (head on). Did 4 shots with 40gr Varget before the minor mishap below happened.
The case on the 5th shot was an increase to 41 gr of Varget. This is still a low pressure load. The case was new and fired for the first time. Is this just a weak case? I've seen this happen with .223 in ARs after a couple of reloads but why this? Is there better brass for 45-70 than Winchester? The wall is pretty thin.
Also, how do I get the rest of the case out? It is stuck pretty good.
Thanks for your comments.
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gelandangan Super Member
Joined: May 07, 2006 Posts: 6396 Location: Sydney Australia
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Posted: Sun Jan 03, 2010 10:32 pm Post subject: Re: Any suggestions for why this case failed? |
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Check the headspace, you probably have a short chamber.
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A smile is the shortest distance between two people.
Do - Not try!
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1895ss Super Member
Joined: Jul 21, 2005 Posts: 2612 Location: Not Here...!!
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Posted: Sun Jan 03, 2010 11:37 pm Post subject: Re: Any suggestions for why this case failed? |
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slimjim wrote: |
Is there better brass for 45-70 than Winchester? The wall is pretty thin. |
I know what you mean about the thin walled 45-70 Winchester brass. I still have some but I use 45-70 Remington brass for my hunting loads now. It is thicker and is much better.
As for the stuck case, as you said the WW brass is very thin and bends easily so, could you push a sliver of wood (eg... round toothpick) down between case and chamber to buckle it and then pull it out? One would want to be careful as to not scratch the chamber.
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Pumpkinslinger Super Member
Joined: Sep 22, 2007 Posts: 5001 Location: NC foothills
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Posted: Mon Jan 04, 2010 12:24 am Post subject: Re: Any suggestions for why this case failed? |
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How easy was it to chamber a loaded round and how much crimp did you use? I'm following Gelan's line of thinking here. I was looking at the ring around the case mouth of the right hand case.
_________________ Mike
"I ain't no better than anybody else, and there ain't nobody better than me!" Ma Kettle |
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slimjim Super Member
Joined: May 16, 2009 Posts: 8314 Location: Fort Worth TX
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Posted: Mon Jan 04, 2010 5:28 am Post subject: Re: Any suggestions for why this case failed? |
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1895ss wrote: |
push a sliver of wood (eg... round toothpick) down between case and chamber |
The broken case is in so tight that I can't get a sliver or toothpick between it and the chamber. It is stuck good. I tried using an oversize brass brush and reversing it but the brass didn't budge. I'm trying some penetrating oil right now. Not sure what that will do but will try it.
Pumpkinslinger wrote: |
How easy was it to chamber a loaded round and how much crimp did you use? I'm following Gelan's line of thinking here. I was looking at the ring around the case mouth of the right hand case. |
I don't use a crimping die, just a Classic Lee Loader. Rounds just slide in. I'm also making sure I index the cases. Regarding the picture, my bad - I went back and checked the brass. The case on the right in the picture is not fired from my rifle. The ones from my rifle have no marks on the lip and are at least .005 below max case length.
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Pumpkinslinger Super Member
Joined: Sep 22, 2007 Posts: 5001 Location: NC foothills
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Posted: Mon Jan 04, 2010 8:01 am Post subject: Re: Any suggestions for why this case failed? |
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OK, thanks for the additional info. Right now I don't even have a good guess as to what happened. Sorry!
_________________ Mike
"I ain't no better than anybody else, and there ain't nobody better than me!" Ma Kettle |
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slimjim Super Member
Joined: May 16, 2009 Posts: 8314 Location: Fort Worth TX
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Posted: Mon Jan 04, 2010 9:43 am Post subject: Re: Any suggestions for why this case failed? |
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looks like I may be off to the gunsmith. Not sure I want to shoot another Winchester case out of this gun. It will be interesting. The case pullers I found on the internet only went as high as .338.
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Bushmaster Super Member
Joined: Jun 12, 2005 Posts: 11390 Location: Ava, Missouri
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Posted: Mon Jan 04, 2010 9:48 am Post subject: Re: Any suggestions for why this case failed? |
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Instead of a toothpick. Try a brass drift that has been reshaped to slip between the case and the chamber wall. Use a small hammer to drive it in to colllapes the case. The brass drift will not harm the chamber as it is steel...
Case seperation of that kind is usually caused by accessive head space...
_________________ I have one nerve left and yer standin' on it...
DEMOCRACY Two wolves and one sheep voting on what to have for lunch...
LIBERTY A well armed sheep contesting the outcome of the vote... |
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slimjim Super Member
Joined: May 16, 2009 Posts: 8314 Location: Fort Worth TX
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Posted: Mon Jan 04, 2010 9:54 am Post subject: Re: Any suggestions for why this case failed? |
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maybe I need to try 1895ss' idea with something other than a tooth pic?
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slimjim Super Member
Joined: May 16, 2009 Posts: 8314 Location: Fort Worth TX
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Posted: Mon Jan 04, 2010 10:13 am Post subject: Re: Any suggestions for why this case failed? |
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Bushmaster wrote: |
Try a brass drift that has been reshaped to slip between the case and the chamber wall. ... Case seperation of that kind is usually caused by accessive head space... |
Bushmaster, thanks. I must not have refreshed my page before I sent the last comment. I may give this a try to remove the brass.
I had a gunsmith check the gun over before I fired it the first time. He said my breech block was not quit square (due to wear) and that I should index my brass to make it last longer. The primers are pushing out some which may be an indication of excessive head space. Not sure how easy that would be to fix excessive head space in a rolling block. Maybe a thicker, less-hard brass would be my best option. I'm not looking to sink a lot of money into this gun. Just want a fun shooter.
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Aloysius Super Member
Joined: Nov 03, 2009 Posts: 2438 Location: B., Belgium
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Posted: Mon Jan 04, 2010 11:46 am Post subject: Re: Any suggestions for why this case failed? |
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Slimjim, on the South Africa forum they give advice for the Lee Enfield to put a small O-ring on the rim before you use that brass for the first time. This way you push the cartridge to the bolt.
And afterwards you just necksize and don't need the O-ring anymore.
The minute I did understand why and how, I also understood I'm still not too old to learn.
What works on a .303 British could also be helpfull for a .45 Government?
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slimjim Super Member
Joined: May 16, 2009 Posts: 8314 Location: Fort Worth TX
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Posted: Mon Jan 04, 2010 11:58 am Post subject: Re: Any suggestions for why this case failed? |
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Aloysius wrote: |
put a small O-ring on the rim before you use that brass for the first time. This way you push the cartridge to the bolt. |
Great tip! Thanks!
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Bushmaster Super Member
Joined: Jun 12, 2005 Posts: 11390 Location: Ava, Missouri
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Posted: Mon Jan 04, 2010 1:28 pm Post subject: Re: Any suggestions for why this case failed? |
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That might just work. Remember though that that case may not fit any other .45-70 chamber...Unless you trimmed them first.
Just thought of something. It may not work because the .45-70 head spaces on the case rim and not a shoulder like on a .303 British...
_________________ I have one nerve left and yer standin' on it...
DEMOCRACY Two wolves and one sheep voting on what to have for lunch...
LIBERTY A well armed sheep contesting the outcome of the vote... |
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Aloysius Super Member
Joined: Nov 03, 2009 Posts: 2438 Location: B., Belgium
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Posted: Mon Jan 04, 2010 3:05 pm Post subject: Re: Any suggestions for why this case failed? |
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Bushmaster wrote: |
Just thought of something. It may not work because the .45-70 head spaces on the case rim and not a shoulder like on a .303 British... |
In that case you keep the O-ring or replace it by a small ring of solder thin. (best do this BEFORE you put a new primer or the powder )
This way you kind of fire form the rim...
Still in my opinion: when you shoot such a rimmed .45-70 and the bold is not completely touching the brass: the powder ignits, pressure increases and pushes the brass to the chamber, bullet starts, pressure increases more and pushes now the bottom of the cartridge to the bolt => because friction is still holding the upper part of the brass, you can get 2 things. Or you have a strong case and only the primer comes backward, or second: somewhere in the case there is a weaker spot and it comes apart.
So keeping the cartridge foot against the bolt when you shoot could solve your problem without big costs to eliminate headspace.
I think I've just earned a beer
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Elvis Super Member
Joined: Jul 27, 2008 Posts: 9239 Location: south island New Zealand
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Posted: Mon Jan 04, 2010 4:03 pm Post subject: Re: Any suggestions for why this case failed? |
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I have had .270 cases do this on the first reload with loads done for me at a sports shop in town. I havent had any do it since I started loading my own. one theory was tight dies and loose chamber causes too much working of the brass but that shouldnt happen on new brass.
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