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08-27-2016, 07:33 AM,
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ken s
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40 70 PP problem
I'm shooting an original 40 70 SS. .403. bore
I'm paper patching a custom 330 and 390 , both custom moulds.
I'm having trouble with getting the patched bullets in the case.
too tight and patches are ripping. some go in, some don't.
I'm patching with .005 onion skin, to .403...but it comes out larger.
I have a .409 expander, but if I go out all the way to 409 the case gets distorted. and won't chamber. it goes too far in the case. full length sizing is then needed.
I've ordered a .410 to 413. Hoping the start at 410 will expand it just enough without going too far in the case.
I use the factory crimp die to tighten around the bullet.
AND. in PP casting...is PURE LEAD BETTER THAN 1 20. IT SEEMS THE ORIGINALS WERE PURE LEAD....
Any thoughts?
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08-27-2016, 11:21 AM,
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Kurt
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RE: 40 70 PP problem
Ken.
Give us a little more information.
What is the brass your using?
Case neck wall thickness?
Chamber diameter at the neck. If you don't have this, what is the diameter of a fired unseized case mouth.
I have never seen Onion skin paper .005" thick.
A double wrap of your .005" thick paper would add .020" to your unpatched bullet.
Your .330" unpatched bullet would be patched .350" and that should fall right through your .403" bore diameter.
The .390" with .020" would be .410" diameter.
The reason a dog has so many friends is because he wags his tail instead of his tongue.
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08-27-2016, 01:20 PM,
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ken s
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RE: 40 70 PP problem
(08-27-2016, 11:21 AM)Kurt Wrote: Ken.
Give us a little more information.
What is the brass your using?
Case neck wall thickness?
Chamber diameter at the neck. If you don't have this, what is the diameter of a fired unseized case mouth.
I have never seen Onion skin paper .005" thick.
A double wrap of your .005" thick paper would add .020" to your unpatched bullet.
Your .330" unpatched bullet would be patched .350" and that should fall right through your .403" bore diameter.
The .390" with .020" would be .410" diameter. sorry Kurt. the diameter of the bullet is .397 and weight is 330 grains.
the paper mikes out at .005, so I'm getting a large .417 result.
It does chamber. and once in the shell it works.
just loading is tough.
The brass is once fired 40 70 SS from Buffalo arms.
thanks...Ken
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08-27-2016, 04:02 PM,
(This post was last modified: 08-27-2016, 04:04 PM by Kurt.)
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Kurt
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RE: 40 70 PP problem
Ok, Well sounds like your trying to use that bullet as a groove diameter.
The .403" bore diameter it sounds like you might have a Remington. I have no idea what your groove diameter is, but with the .403 bore diameter and a .417? diameter bullet you will have a hard time loading the round unless the ogive is seated off the lead.
I take it that the Buff arms cases are the stretched .30-40 brass. If so the wall thickness is .010" +- some maybe. So you will need a chamber dimension at the case neck at least .437" to load that round with out to much thumb pressure and a clean throat between shots.
Ken all of this is a guess with out knowing what exactly you have for a chamber.
But I would suggest you get some paper that is two thousands or less in thickness and give this a try.
You can find some thinner paper at Walmart in the craft section or ask. at a paper store. Take a micrometer with you when you look for paper. With your .403 bore .0023" thick would be just fine for shooting the bullets closer to bore. I like mine patched one thousand over bore for my rifles. But if you want to go for groove diameter patched bullets then adjust your paper close to your groove diameter and seat your bullet depth accordingly for your chamber. It's not a good idea to go to much over groove diameter. I wouldn't go more then one thousands over groove if this is your intend.
Then work up a ladder load from zero to top compression you feel you need in one grain intervals 3 shots each. Usually 21 rounds fired will give you an idea what to tune up a little more.
Kurt
Kurt
The reason a dog has so many friends is because he wags his tail instead of his tongue.
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08-28-2016, 08:49 AM,
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ken s
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RE: 40 70 PP problem
thanks Kurt. I have the new Jamison Brass, once fired, and the gun is an Original Sharps 74 sporting rifle with a great bore. .
I'll try some paper that is a little thinner. off to the store with my micrometer! Thanks..>Ken
I am getting 2 to 3 inches at 50 yds....short distance, but it is working. I clean between shots and generally they chamber.
The 330 grain chambers, but the longer 390 will sometimes have trouble if I don't clean well...
oh, the journey...huh? Ken
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08-28-2016, 09:11 AM,
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Kurt
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RE: 40 70 PP problem
Very good. I bet that original Sharps has a very shallow groove. That works good with paper patching.
You will get this all ironed out when you shoot it.
Kurt
The reason a dog has so many friends is because he wags his tail instead of his tongue.
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09-23-2016, 11:24 AM,
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ken s
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RE: 40 70 PP problem
[quote='Kurt' pid='18698' dateline='1472389883']
Very good. I bet that original Sharps has a very shallow groove. That works good with paper patching.
You will get this all ironed out when you shoot it.
Kurt
[/quote
right Kurt. very shallow groves, and the latest is 1 1//2 inch groups at 50 yards. time to go to 100
I cleaned up the bore with a careful wipe of valve grinding compound on a cloth, wet, and then full length draws with jewelers rouge, again wet.
the cleaning patch slides down the bore .
and the groups cut in half.....
Ken
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