how accurate do you have to be when measuring cases
- Thread starter Tak
- Start date
- Location
- Prince Albert, Sk
yes!!!
get a new micrometer, brass size is pretty dang important for accuracy
get a new micrometer, brass size is pretty dang important for accuracy
Well I resized brass with the correct Die and the sizes I get are off compaired to the standarts in the book. And different brass I sized with the same die don't give the same dimensions...
What else could it be?
Also I got some new brass and the micrometer doesn't show the propre measure. Isn't new brass supposed to be sized already?
Actually it's a vernier
What else could it be?
Also I got some new brass and the micrometer doesn't show the propre measure. Isn't new brass supposed to be sized already?
Actually it's a vernier
You mean the length? That will be all over the map new, used, resized or not unless you've trimmed the cases with a really good trimmer, which you haven't.
Vernier's don't go off.
If you have a known-sized object, try measuring it. Good quality target bullets for rifles generally consistent diameters. Or find a buddy with a set of calipers or micrometer and compare its readings to yours on the same object.
go buy a $14 digital vernier from CT and check your mic. The only way it could be off like that is if you've been filing the anvil or performing other strange behaviour. 
Why check the diameter of your cases anyway? As long as they chamber?
Why check the diameter of your cases anyway? As long as they chamber?
Guess what,the actual case dimensions are rarely exactly the same as the SAAMI dimensions in a book.Measure a known dimension to check your micrometer.Even a bullet will be a much better reference than a cartridge case.
Good to know
so basically, as long as they get through the die, All I have to worry about is case lenght and OAL ?EDIT : You were right guys, the bullet I measured reads straight .308 on the vernier
This would mean that
1- I have to lenght trim my brand new 300 win mag casings
2- The once fired 30-30 cases need trimming already
You are expecting perfection from a mass manufactured item that is not manufactured to a specification that you are expecting.
Your brand new .300 win mag cases should not need trimming. I find that it is best to trim them to the 'trim to length' after the first firing and after they are full length resized.
I also trim all of my .30-30 cases to the same length after their first firing and full length resizing, so that I have a common case length for crimping.
You don't need to be absolute on your trim length. As long as they are shorter than the maximum, they should be the same length.
Your brand new .300 win mag cases should not need trimming. I find that it is best to trim them to the 'trim to length' after the first firing and after they are full length resized.
I also trim all of my .30-30 cases to the same length after their first firing and full length resizing, so that I have a common case length for crimping.
You don't need to be absolute on your trim length. As long as they are shorter than the maximum, they should be the same length.
Where are you located? From your many posts, where you appear to be obsessed with many small details that you don't need to be (and you don't appear to have enough experience to know what you need to know - this is not a slag, but I believe you have said that you are a newbie), it might be useful if you were able to link up with someone and go through it all in person.
"...Isn't new brass supposed to be sized already?..." Nope. New brass needs to be full length resized, checked for length, trimmed if required and chamfered and deburred. The chamfering and deburring allows easier bullet seating.
"...All I have to worry about is case length and OAL..." Pretty much. Two different things though. Having your cases all the same length makes getting the OAL the same easier.
"...The once fired 30-30 cases need..." That's not unusual. Cases used in a lever action, must be FL resized too. Has to do with the strength of how lever actions work. The extractor has to pull it straight out with no camming like a bolt action.
"...All I have to worry about is case length and OAL..." Pretty much. Two different things though. Having your cases all the same length makes getting the OAL the same easier.
"...The once fired 30-30 cases need..." That's not unusual. Cases used in a lever action, must be FL resized too. Has to do with the strength of how lever actions work. The extractor has to pull it straight out with no camming like a bolt action.
go buy a $14 digital vernier from CT and check your mic. The only way it could be off like that is if you've been filing the anvil or performing other strange behaviour.
Why check the diameter of your cases anyway? As long as they chamber?
My reloading buddies and I use the Crappy Tire ones and they work just fine. They go on sale every few weeks for 60% off.
http://www.canadiantire.ca/AST/browse/6/Tools/MeasuringTools/SpecialtyMeasuring/PRD~0586800P/Mastercraft%252BDigital%252BCaliper.jsp?locale=en
I'm in Quebec, and well yes I'm new to this, that's why I'm trying to learn from 3 sources, this forum, a good video I found on internet and the Lyman's book. The book says trim to lenght and max lenght equals x and y, I try to get x or y
I size and get dimensions that aren't like in the book, I wonder if it's normal
I don't know yet what is important and what's not, so I don't wanna take any chances. I've read a good part of the manual already and when ever I don't get awnsers to my questions I comme here hehehe.
I also generaly try to do the things I do as well as possible, no point in learning something if you learn it the crappy way
@ Sunray : Thanks alot it's pretty good to know I'm not totally crazy
