So I am Making this Measuring DooDad!

USMCDOC

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It is used to measure the rim thickness of 22LR cases.. i am not done with it yet, but i am getting closer.. still have a lot of bling yet still to put into it!

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Looookin good! So the casing goes into a block of steel with a hole in it sized to catch the rim from the underside? Then you compare/measure the top? Correct?
 
pardon my ignorance, but why would you need to measure the rim thickness on .22 shells?o_O
can the thickness be adjusted ? or is merely to know how thick they are in comparison to each other?
i'm assuming it will have effect on headspace, but as i said i'm trying to wrap my head around measuring .22 shells...
i'm further assuming that serious deviations would create ballistic variables downrange?
help!:blowup::grin big:
 
pardon my ignorance, but why would you need to measure the rim thickness on .22 shells?o_O
can the thickness be adjusted ? or is merely to know how thick they are in comparison to each other?
i'm assuming it will have effect on headspace, but as i said i'm trying to wrap my head around measuring .22 shells...
i'm further assuming that serious deviations would create ballistic variables downrange?
help!:blowup::grin big:
I think perhaps he is trying to achieve consistency by sorting and grouping his ammo by the various variables in the quest of better accuracy. Case I.D., cartridge OAL, case diameter, and perhaps other things could also be sorted on. If it makes a difference, it can be the difference between winning and losing when match shooting. If I did that, it would only take away my alibi, because most any gun is more accurate than me...
 
Not sure but if the rim is thin it will not ignite correctly. The primer is poured into the case as it rotates then it's dried before the powder is dropped and bullet seated , most are lightly crimped . By cking the rim you can almost find the ones who will miss fire. Anybody that's shot rimfries has had ones that don't go off . Sometimes turning and fired again they will go off. Not every time but sometimes .
 
I used to shoot over 1500 a week. Ya, that's a lot but for someone to make their own ammo it is like Bob says, Consistency. Each slug I pourred is carefully weighed, powder masured to very high fine weights, even primers can be weighed. Cases are supper cleaned and inspected for flash hole dia. concistence. So for match shooting that UMCdoc is most likely doing, it is the difference of a win or 2nd place.
 
it's funny, i have shot over 10,000 .22 rounds in my life- i never had one not go bang when i pulled the trigger

centerfire ammunition, well that's another case completely
i had some persian headstamp 7.5 French that was scary to shoot. 3 out of 4 would shoot. the 4 th one wouldn't.
i had one of the persian shells detonate a full 2 seconds after the trigger was pulled, luckily i still had the round chambered and aimed downrange.:eek:
 
Whether it's beneficial or not may be debatable, and probably should be debated on a different forum, but I think it's a pretty cool piece of work. I'm considering something similar but for different measurements of reloaded centerfire cartridges. I hope mine turns out as well as USMCDoc's.

Tom
 
i agree that the debate of the effects should be somewhere else.. but i will state that the argument is that sorting by rim thickness of 22lr shells does not improve or make you ammo "more" accurate.. i agree with that statement.. but sorting by rim thickness has in the past proven to me that it makes those "flyers" more consitant.. meaning.. lets say that cases that are minus 2 in deviation from the "0" case (which is the one that you zero the gauge to) are flyers that land at 10 o'clock in a no wind condition. Would you want to have them just randomly land there or have them all concentrated together so that they all land there consistently, just center up on the target.. that is the jist to sorting.. it does seem to help with lower level match ammo.. but say Lapua Center X or Black or Red box Eley.. it don't seem to help too much with that ammo.. but i know a guy that is weighing his Center X ammo.. and doing good with it..

i used to be a center fire competitor.. long range, Palma and the sort. And sorting does make a difference.. i would be interested in what your deciding to do.. maybe i can help..
Whether it's beneficial or not may be debatable, and probably should be debated on a different forum, but I think it's a pretty cool piece of work. I'm considering something similar but for different measurements of reloaded centerfire cartridges. I hope mine turns out as well as USMCDoc's.

Tom
 
It is said that there is with certain 22lr chambers that there is a "rim" thickness that the rifle will like better than the others.. so the quest is to find that.. it is said that .041 headspacing is the best.. The ammo i was checking all was running around .031 in thickness.. i need to check some Lapua Center X, my rifle seems to like that stuff!
pardon my ignorance, but why would you need to measure the rim thickness on .22 shells?o_O
can the thickness be adjusted ? or is merely to know how thick they are in comparison to each other?
i'm assuming it will have effect on headspace, but as i said i'm trying to wrap my head around measuring .22 shells...
i'm further assuming that serious deviations would create ballistic variables downrange?
help!:blowup::grin big:
 
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