.45ACP actual case length compared to SAAMI specs

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I believe he is letting @Stimovsky know that the tolerance on brass length measurement is a little bit more than a half thousandth.
And that it errs to the short side, as being too long(a "plus" measurement) would keep the firearm from chambering the round and reaching battery.
 
^^^^ I took it that way as well. We all pretty much take it that you take a pistol brass resize it and use it to reload with not bothering to measure as it was OK the previous firing-----most of us. Until that day when it does not work and then we start to measure and learn things we took for granted might need to be fine tuned in our brains. Also I see some that measure every casing and adjust for differences in batches. It may make better ammo but the things we do prepping brass reach a point of diminishing returns, as for me if I cannot see an improvement I do not bother with those most minute things in the future. YMMV
 
Never measured a handgun caliber case….never going to. .223 is a big enough PIA. lol

LONG ago I tried to be the level of shooter for whom this level of ammo precision would be even detectable. Gave up the quest a LONG time ago too. lol
 
I sorted some 2000+ 45acp brass years ago by length. It was just to see if what I had read on head spacing was true. What I was looking for was the long ones that were in the 0.001"-0.003" short of my chamber length. What I found was 98-99% were shorter than that, with most toward the lower end of the spec. These were unsized brass. Going on memory I believe I found enough to make up a box or two. The reason was to test if my BE gun would shoot more consistent tighter groups. It actually does but not worth the effort. It really lowered the SD of the rounds. I do keep those separate from the rest since I went through all the work to find them.

Would I do it again, NO.
 
I kinda sort of would like to know what instrument and brand he is using to measure brass accurately out to .0001 variance?:scrutiny:
 
To explain the 4-digit values: I thrown all my measurements in an excel sheet, averaged them and kept just as many numbers as the caliper displayed.
I just read about accuracy, precision and resolution. Lesson learned (I guess?): I'll pay more attention to significant numbers.
I'm currently working on another 100 batch, new data will probably make more sense.
 
Stimovsky said:
It's supposedly accurate up to .0005"
Click to expand...
Digital calipers like that just round off to the nearest .0005. Good ones are OK for for measuring to .001.

From the link:
PRECISION | ACCURACY: Measurement Range: 0 - 6” and 0 - 150mm; Resolution: 0.0005” / 1/128” / 0.01mm; Accuracy: 0.001” / 0.02mm
Click to expand...
 
Okay, I have them right now under my scope, I count 8 of them : measure, accuracy ,uncertainty, precision, fluctuation, resolution and sensitivity.
If none of you guys invite Heisenberg to this discussion, maybe we can close the thread.

I know I only listed 6 fairies
 
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Some handgun case gages, and maybe rifle case gages also are made to the SAAMI maximum case dimensions and others are made to the SAAMI minimum chamber dimensions. Consequently different brands of case gages give different results. I use a L.E. Wilson case gage and I dpon't sweat it when the round does not fall all the way to the bottom.
 
Darn another thing I have to add to my list of "New Years" things to do. aka Resolutions

Organize two 5gal buckets full of 45 ACP brass not only by head stamp, but deprime, clean in a wet tumbler,uniform primer pockets, ream flash holes resize, measure each one in a gauge (buy gauge) and place in individual labeled containers throwing away all that are not within .0001"
:);):scrutiny:
 
Rule3 said:
Darn another thing I have to add to my list of "New Years" things to do. aka Resolutions

Organize two 5gal buckets full of 45 ACP brass not only by head stamp, but deprme, clean in a wet tumbler,uniform primer pockets, ream flash holes resize, measure each one in a gauge (buy gauge) and place in individual labeled containers throwing away all that are not within .0001"
:);):scrutiny:
Click to expand...
Sir: IMHO, and I've been reloading & shooting .45 auto for some 50+ years, it would almost pay you to collect only 1 brand of .45 auto cases, if you are going to put yourself through all that. Unless you are a B/E shooter, or are capable of shooting a 3.5" 10 shot group or less @ 50 yds most of that is unnecessary and will not improve handgun accuracy. What dimension or measurement should be within .0001. Just kidding, but you like zeroes, huh. I shoot indoors, save all of my brass & do not pick up others brass. Nor do I collect range brass. Just some random thoughts, Sir.
However, virtually all of your ideas are pretty much minimum requirements for long range bench rest shooting.
 
Rule3 said:
Darn another thing I have to add to my list of "New Years" things to do. aka Resolutions

Organize two 5gal buckets full of 45 ACP brass not only by head stamp, but deprime, clean in a wet tumbler,uniform primer pockets, ream flash holes resize, measure each one in a gauge (buy gauge) and place in individual labeled containers throwing away all that are not within .0001"
:);):scrutiny:
Click to expand...
I really think you should do it............ :D
 
Rule3 said:
Darn another thing I have to add to my list of "New Years" things to do. aka Resolutions

Organize two 5gal buckets full of 45 ACP brass not only by head stamp, but deprime, clean in a wet tumbler,uniform primer pockets, ream flash holes resize, measure each one in a gauge (buy gauge) and place in individual labeled containers throwing away all that are not within .0001"
:);):scrutiny:
Click to expand...

I'll pay the shipping if you'll send that reject brass my way.
 
I wouldn't invest a large sum of money in a case trimmer for 45acp
Click to expand...
A what to do what? Trim 45 ACP?:eek::what:
That would mean I need to measure it to see if it needs to be trimmed:evil::), heck I just load it and shoot it, worked so far for 10K+
 
Mowgli Terry said:
Is there a Troll at Handloader magazine.
Click to expand...

There are also many Trolls at Hornady. They claim the 45 AUTO head spaces on the case mouth but what do they know? The must not surf the Web.

And what about Walkalongs infamous Picture of the case "plunk"??

45 ACP Barrel Seating.jpg
 
The only problem with the one being to long is that most productions guns have clearance between the barrel and breach face. I believe the spec Colt uses allows for 0.010" gap. The most accurate guns have a hard lock up, meaning there is not no gap at the breach face and no loose fitting bushings. At least for the 1911's. I had one of the top BE builder of 1911 says you will get your best groups when the brass length is 0.001"-0.003" your chamber length. This minimizes the shift in the brass during firing and seals of gases the fastest.

But in general it's correct but it changes due to head spacing on the mouth of the brass. Mixed brass except 0.010" variance and maybe more.
 
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