Miguel's Reloading Journey: calipers

[miguel]

This is the first in a series of no-nonsense posts related to buying reloading equipment and related gear. Take it for what it's worth. I am neither a ballistics engineer, a metrologist, nor a paid spokesman for any of the gear I may report on. As of this writing, I have reloaded a grand total of 25 rounds of 45 ACP, so you will want to seek a second opinion when in doubt! These experiences are mine and may have little validity in your particular circumstances.

After taking Andrew's class in April, I have started to earnestly research equipment that I believe will meet my needs and budget to safely reload my own ammunition.

The first thing I've learned is that in every case, it is SAFETY FIRST when reloading! That being established as my sine qua non (without this, nothing) I've been primarily focused on finding calipers that will accurately allow me to measure OAL ("overall case length" -- aka COL [case overall length]) so I don't make rounds that are too long to chamber or so short they will cause pressure spikes or worse. Of course a case gauge will resolve the "too long" part, but I digress...

I have spent, at minimum, ten hours researching calipers and trying to decide which are "good enough" for a hobby that, worst case, could lead to a nasty injury -- or worse -- to my gun, me or someone else nearby. With that context, I wanted to make sure that anything I used would give me the confidence to proceed on my journey.

One of the first things you'll learn about calipers is that there are, at least, three different type that can be useful for reloading: vernier, dial and electronic, aka digital.

Vernier calipers are old school, manually read devices that, in the case of reloading, should give you measurements as granular as .001" or better. A very useful video that helped me understand how a vernier caliper is read is available on YouTube here:

http://www.youtube.com/watch?v=Vz40xmrdhyY

Being a traditional bastard, I like the idea of getting a pair of these some day, but I didn't want to get those right off the bat. In my opinion, they are the James Dean of calipers...unquestionably cool. There are any number of manufacturers of these devices from mass-produced Chinese versions to those made my Swiss and Japanese companies that likely have more quality control. Of course, the more the actual (and/or perceived) quality, the more you will pay.

Next type of caliper...dial calipers. These are actually the first kind I ever used and they basically look like a ruler with a small stopwatch attached to them. Dial calipers have jaws just like any other caliper, but their reading is provided on a mechanical dial (imagine an odometer as granular as one thousandth of an inch!) and are adjusted with either a thumb-wheel or other thumb-powered protrusion on the body of the tool. Like the vernier calipers mentioned above, these range in price based on the granularity of their measurement and the quality of their manufacture. I'd like a pair of these someday, too.

Last type of caliper that I'll cover...the kind for the 21st Century and the kind I ended up buying...electronic/digital calipers! These are said to be easier to read and look like a ruler with the display from a 1980s digital watch attached to them. Electronic calipers of various granularities can be found and like their caliper brethren, run the gamut from cheapo models to ones in the hundreds of dollars. Heck, there are even versions that have a USB port to load your data onto your computer. That is intriguing, to say the least, but they have a price tag to match their intrigue, of course!

As I did my research, it became quite clear that several brands stood out from the pack -- or did at one point in time -- specifically: Mitutoyo, Starrett and Brown & Sharpe. Got $300? Then they have a caliper for you! Honestly, their entry level models tended to come in at just under $100 depending on the vendor chosen. And that brings up another point...there appears to be a limited selection of calipers in big box type stores, at least in Hamilton County and northern Indianapolis. I hit Harbor Freight, Lowes, Home Depot, Menards, Sears, Tractor Supply, Ace Hardware and basically found calipers that were either not granular enough (metrics, fractional, good to .01", etc.) or looked like my son made them at school. Granted, there were many branded models of calipers on the reloading sites (Midway USA, Grafs, etc.) but before I dropped money online, I wanted to get my hands on a pair to feel comfortable with my purchase. While I'm not from Missouri, I do want to feel comfortable with things I buy online, especially when I've got zero experience with such a tool. I mean, it's not like a book where every copy is like the next.

In my eagerness to actually get a pair on the quick, I decided on a digital caliper from Harbor Freight. I took a set out of the box at the store and while they felt a little cheap, I thought, "I'll buy them, try them and bring them back if they suck." The pair in question was:

6" Digital Caliper with Metric and SAE Fractional Readings

Once I got home, as an experiment, I decided to measure some US quarter dollars, which are allegedly 0.955" from the mint. I assumed there could be some variation in individual specimens, depending on whether they sat in a jar or had circulated quite a bit, but they provided me some frame of reference. Well, once I got them out of the box, I could tell I had been had. Damn thumb wheel turned but the jaws didn't open or close!

I was so disappointed in them, I'd have returned them that night if it wasn't for the fact it was storming and HF is a 40 minute drive from my house! I did end up taking them back the next day, where a cheerless gal asked, "Anything wrong with them?" My reply, "Wasn't the quality I was looking for." was all I could muster with a straight face. Her eyes said, "Ya think?" as she handed me my cash back...

After this, I hated the thought of going online and dropping $100 for a pair of Mitutoyo vernier calipers...I mean, I liked the idea, but couldn't do it. Not yet, anyway. While scouring several popular forums, I had read several posts that alleged -- accurately or not, I do not know -- that unless you are benchrest or bullseye shooting, +/- .005" is plenty accurate for a handgun OAL, especially if plinking. Since that is primarily what I want to reload for, and knowing I could always return them, I decided to return to Lowes, where I had seen a pair of calipers that, visually at least, appeared to be of slightly higher quality (translation: didn't totally look like chum) than the others I'd actually seen in person. Specifically, they were the Kobalt model: Shop Kobalt 6" Metric and SAE Caliper at Lowes.com

They had eleven reviews, with an average of four stars. Throw out the guy who gave it one star and didn't elaborate why ("Do not waste your time and money. Either get a $6 plastic one, or spend the bucks to get a real tool.") and I thought they would be worth the risk, again knowing I could take them back and move on to the Mitutoyos.

I picked them up Sunday night and came home hell bent on vetting them. While my science certainly may be in question, I am satisfied I made a good purchase based on it. Here goes...

Since I am not a machinist and didn't have any gauge blocks, I went to my dresser and found seven US quarter dollars. Again, the A-bomb wasn't built on this type of science, but my experiment only had to satisfy a simple liberal arts grad, not Stephen Hawking. I used quarters since I had a nominal factory dimension (0.955") on them and they were abundantly available. I was going to run the same test using dimes and pennies, but as I have some semblance of a life, I didn't want to have this test take all night!

On principle, I decided to document each coin to make sure I could uniquely identify it (none from the same year) and measure it three times. That would give me a decent sample to see how consistently their measures were. Note I didn't mention the accuracy of the measure, but the consistency of the measure. Without gauge blocks, I'm at the mercy of being able to test only the consistency of this device's measurements. That said, I do plan to get some certified gauge blocks to see just how accurate these things are.

I decided to measure each coin once, then move on to the next coin. The calipers were zeroed between each measurement and actually turned off between each "series" of measurements. I also made it a point to get up and walk around for a few minutes between each series. Data was tracked in Excel and the previous measurement of the coins was hidden so as not to psychologically impact my current measurement.

Once I finished and ran the numbers, I was pleased to see that four of the seven coins measured the same every time. Three of those had pre-2000 mint dates. The fourth coin with a zero variation across the three measurements was a "Colorado" quarter from 2006, which hit 0.954" each time. The other coins, which each had a single variation between their three measurements, all were off only 0.001" in each instance, which is the stated accuracy for the calipers. Also of note, the three coins with variations were post-2000 "state" quarters. I guess Bush was responsible for that, too...

While these are small sets of data, to be sure, I felt that accurate or not, these calipers were consistently measuring the objects in question. I'd post the standard deviations I calculated in Excel, but I think that would be a little uppity for such a small number of measurements.

Only with a certified tool or gauge will I know for sure, but I'm feeling confident enough that I will keep these calipers, but will remain on the lookout for an additional set -- hopefully an old school vernier! -- to cross check them against.

p.s. Of course, the editor of Miguel's Reloading Journey will be happy to accept gifts of calipers or gauge blocks -- even on loan! -- should you wish to contribute them to the cause.

p.p.s. I know this post was kinda long, especially just over a pair of calipers, but hopefully you enjoyed the read, and someone who follows me down the reloading path will not spend as much time I did on these things!

 

[jedi]

Oh you virgin reloader you.
Looks like I'm ahead of you by 350 rounds.
I have fired 50 rounds so far and have reloaded a new batch of 350 last night (230 gr FMJ, Winchster 231 - 5gr, CCI primers). This time the calpiers only came out once to measure the very first round I did. Since I did not move/adjust my dies from last time and the last 50 rounds all worked I figured the bullet setting is OK so no more need for fine-tune measuring.

I'm glad I did not spent $100+ on my calpiers since at this point it's a tool I don't really thing I will use much for .45 ACP plining ammo. I see how they are useful when you are making precision rifle ammo but for me right now they will be a once in a while tool.

-Jedi

 

[miguel]

What can I say Jedi, I just love calipers!

Had so much fun researching them, I actually went to the Ivy Tech website and started looking into machining classes. A man's gotta have options in this economy, you know!

 

[U.S. Patriot]

Calipers are a handy tool, for much more than reloading.

 

[Broom_jm]

I can empathize with how thorough you are in your examination of something new, prior to spending your hard-earned money on equipment. I am wont to do the same; loathing the idea of paying any money for junk, but equally suspect of paying top-dollar for a "name", instead of something that simply works like it's supposed to work.

I am fortunate enough to have a father who is a jet aircraft mechanic. Vernier calipers and actual micrometers were items I was well-acquainted with by the time I was in my teens. When I learned that calipers only need to be accurate to within half a ten-thousandth, I knew the Mitutoyo set dad and I had used to measure stuff with would more than suffice.

I also learned to rely upon the conventional wisdom of those who preceded me on this path of reloading independence. I'm not saying you should jump off a bridge, but if dozens of experienced reloaders suggest getting a certain make/model of widget for a particular need, I usually respect their opinion and do not quibble about the price.

A word about electronic doo-dads: I have a digital scale. It works. I verify it against a Dillon beam scale, frequently. Why? Batteries die and as they are dying, electronic things do weird stuff. I am so used to reading a dial caliper I don't think it would be any advantage to me, using a digital model. To each his own. I'm getting old and have earned the right to be curmudgeonly, at times.

Continue being vigilant, but be advised that you needn't spend 10 hours one each item to determine what will, and will not, work well. Like so many consumer items, disregard those costing the absolute least/most and focus on reviewing the product in-between. One of them will likely be just about ideal for your needs.

 

[Broom_jm]

Oh you virgin reloader you.
Looks like I'm ahead of you by 350 rounds.
I have fired 50 rounds so far and have reloaded a new batch of 350 last night (230 gr FMJ, Winchster 231 - 5gr, CCI primers). This time the calpiers only came out once to measure the very first round I did. Since I did not move/adjust my dies from last time and the last 50 rounds all worked I figured the bullet setting is OK so no more need for fine-tune measuring.

I'm glad I did not spent $100+ on my calpiers since at this point it's a tool I don't really thing I will use much for .45 ACP plining ammo. I see how they are useful when you are making precision rifle ammo but for me right now they will be a once in a while tool.

-Jedi

Am I reading this right? You loaded 350 rounds and literally only measured the first one? You have too much faith in your seating die.

Just for grins n' giggles, what say you go back and spot check another 5-10 rounds, from throughout your efforts? And for future reference, take it from guys who have been forced to pull HUNDREDS of bullets in the past: Stop and measure every once in a while, to make sure nothing has changed. Particularly where pistol loads are concerned, it totally sucks to find out that bullets started seating .015" deeper when you weren't paying attention. Dude, seriously!

 

[U.S. Patriot]

Only measuring 1 out of 350 rounds is asking for trouble. I do not care what dies you are using, you never just trust a piece of equipment. I check every tenth round myself. It takes a matter of seconds.

As for the caliper, I do not like digital. I worked as a machinist, and I do not trust digital calipers. Also, I have found you do not need to spend top dollar for an accurate pair of calipers that will hold calibration. I knew guys that would buy the top brands and pay big $. Yet, my less expensive set of calipers would give me the exact same measurement.

 

[miguel]

I also learned to rely upon the conventional wisdom of those who preceded me on this path of reloading independence. I'm not saying you should jump off a bridge, but if dozens of experienced reloaders suggest getting a certain make/model of widget for a particular need, I usually respect their opinion and do not quibble about the price.

...

Continue being vigilant, but be advised that you needn't spend 10 hours one each item to determine what will, and will not, work well. Like so many consumer items, disregard those costing the absolute least/most and focus on reviewing the product in-between. One of them will likely be just about ideal for your needs.

I hear you, man. I realize now if I make myself do this for each item, I may not start reloading until 2015!!!

First purchase is always the hardest, I guess.

 

[shibumiseeker]

Heh. I never used calipers until I'd reloaded a few tens of thousands of rounds, and only then when I got into precision rifle shooting.

I'd just compare to factory brass or ammo and move on

Now of course that I own several sets I use them all the time.

 

[cundiff5535]

Am I reading this right? You loaded 350 rounds and literally only measured the first one? You have too much faith in your seating die.

Just for grins n' giggles, what say you go back and spot check another 5-10 rounds, from throughout your efforts? And for future reference, take it from guys who have been forced to pull HUNDREDS of bullets in the past: Stop and measure every once in a while, to make sure nothing has changed. Particularly where pistol loads are concerned, it totally sucks to find out that bullets started seating .015" deeper when you weren't paying attention. Dude, seriously!

Thank you for this post sir... I am about to start researching reloading and this never even come into my thought process! I am sure I would have been told to do so but, at least I know that this is a must

Looks like I will be testing every 10-20 rounds

 

[jedi]

Am I reading this right? You loaded 350 rounds and literally only measured the first one? You have too much faith in your seating die.

Just for grins n' giggles, what say you go back and spot check another 5-10 rounds, from throughout your efforts? And for future reference, take it from guys who have been forced to pull HUNDREDS of bullets in the past: Stop and measure every once in a while, to make sure nothing has changed. Particularly where pistol loads are concerned, it totally sucks to find out that bullets started seating .015" deeper when you weren't paying attention. Dude, seriously!

I did put every 20th round into my case guage (of the 350 I did) and they all were OK. I was looking more closely at the "too short" line/groove and none of them were too short.

What would I go back and be measuring with the calipers?
The OAL?

 

[miguel]

Thank you for this post sir... I am about to start researching reloading and this never even come into my thought process! I am sure I would have been told to do so but, at least I know that this is a must

Looks like I will be testing every 10-20 rounds

Take Andrew's class if you can. He covers everything like this and you can hammer him with all your questions afterwards.

 

[Broom_jm]

I did put every 20th round into my case guage (of the 350 I did) and they all were OK. I was looking more closely at the "too short" line/groove and none of them were too short.

What would I go back and be measuring with the calipers?
The OAL?

OK, if you put every 20th round in the case gauge, that tells you your bullets are likely not seated too long and that the belling of the case mouth has been removed effectively, but how do you ensure your bullets are not seated too deeply into the case? If you are eye-balling that measurement against anything other than a cannelure or crimp groove, it can be really difficult to tell if they are of the correct length.

With semi-auto pistol rounds, bullet seating depth is a pretty critical measurement. If your bullets are seated too long or the case mouth belling is not removed, you rounds don't chamber properly, but that's not the most dangerous condition. If your bullets are seated too deep into the case, that can drive start pressures up very quickly. Of all the potential problems associated with loading semi-auto pistol rounds, this is the one that folks get into trouble with, most often.

 

[miguel]

With semi-auto pistol rounds, bullet seating depth is a pretty critical measurement. <snip> If your bullets are seated too deep into the case, that can drive start pressures up very quickly. Of all the potential problems associated with loading semi-auto pistol rounds, this is the one that folks get into trouble with, most often.

This is ultimately my concern, which led me to a 10+ hour investigation of calipers!

How deep is too deep? I'm sure it's caliber and recipe specific, but I've had a hard time finding a universal tolerance for what is "too" short. The only thing I've found is some random posts about OAL +/- .005" being "good enough". Sounds reasonable, but far from a ringing endorsement for my simple self.

Assuming one accepts that OAL - .005" is good enough, if your OAL measurements are potentially .001" or .002" off due to caliper (in)accuracy, is that an absolute no go or does it fall under "close enough to good enough"?

Plus, I've got those evil, unsupported Glock chambers to worry about!

 

[billybob44]

Brown & Sharpe Dial Type..

^^^This is what I used..Bought them about 35 years ago (for $15.00!!) from a co-worker that was hurting for $..

I like others, trust the Dial type more than the electronic type..Bill.

 

[U.S. Patriot]

Back on the subject of measuring rounds after the seating process. On occasion, I have had bullets seat to deep. I visually check every round when it comes off the press. If it does not look right, I measure the OAL. If I would have not caught those rounds, it could have turned into a bad situation. Reloading is not a joke. It only takes that one time.

 

[Mr Evilwrench]

I've been using this stuff since I was a teenager, and I've picked up a few choice items at auctions, garage sales, whatnot. I have a couple of digitals, and they have some nice features, like instant conversion and differential measurement. Mostly I use the dials, though. My real prize is the 0-6 mike set.

 

[jedi]

OK, if you put every 20th round in the case gauge, that tells you your bullets are likely not seated too long and that the belling of the case mouth has been removed effectively, but how do you ensure your bullets are not seated too deeply into the case? If you are eye-balling that measurement against anything other than a cannelure or crimp groove, it can be really difficult to tell if they are of the correct length.

With semi-auto pistol rounds, bullet seating depth is a pretty critical measurement. If your bullets are seated too long or the case mouth belling is not removed, you rounds don't chamber properly, but that's not the most dangerous condition. If your bullets are seated too deep into the case, that can drive start pressures up very quickly. Of all the potential problems associated with loading semi-auto pistol rounds, this is the one that folks get into trouble with, most often.

First I'll give you my data and then I'll ask the question.
Box 1 - 50 rounds
Round 10 = 1.271 OAL
Round 20 = 1.271 OAL
Round 30 = 1.271 OAL
Round 40 = 1.270 OAL
Round 50 = 1.270 OAL

Box 2 - 100 rounds
Round 10 = 1.271 OAL
Round 20 = 1.271 OAL
Round 30 = 1.271 OAL
Round 50 = 1.270 OAL
Round 70 = 1.271 OAL
Round 100 = 1.271 OAL

Box 3 - 100 rounds
Round 10 = 1.271 OAL
Round 50 = 1.271 OAL
Round 100 = 1.271 OAL

Box 4 - 100 rounds
Round 10 = 1.271 OAL
Round 50 = 1.271 OAL
Round 100 = 1.271 OAL

So all the rounds are the same. Which is at the same OAL as the first 50 rounds I did and fired and those all worked. I did not change/mess with my dies so why should/would I expect a different result.

I'm not being a smart-butt but being a n00b just like the OP would like to know and thus my question.

I measured my bullet and it's .6535 for a .45 230gr FMJ BTW.
The brass cases I'm using are mixed range pick ups.

This is ultimately my concern, which led me to a 10+ hour investigation of calipers!

How deep is too deep? I'm sure it's caliber and recipe specific, but I've had a hard time finding a universal tolerance for what is "too" short. The only thing I've found is some random posts about OAL +/- .005" being "good enough". Sounds reasonable, but far from a ringing endorsement for my simple self.

Assuming one accepts that OAL - .005" is good enough, if your OAL measurements are potentially .001" or .002" off due to caliper (in)accuracy, is that an absolute no go or does it fall under "close enough to good enough"?

Plus, I've got those evil, unsupported Glock chambers to worry about!

I'm with you miguel on this one. Indeed what is "too short" of an OAL? All the books I've seen and data I have looked up just give the MAX OAL. I went based off LEE's data which said MAX OAL is 1.275 for the .45 ACP.

When I did my first 50 I took a factory round (Federal) and measured it and that came out to 1.271 so when I was setting my dies (especially the bullet seater die) I figured well if the factory round is at 1.271 and that works in my gun I guess i should try and match that since it was under 1.275.

Made a mistake on the first bullet I did as I set the bullet seater die the wrong way and the bullet was seated ALL the way into the brass (no powder was in the case).

So then I turned the die the other way and reseated and checked OAL. That was way too big (greater than 1.275) so I kept turning it and checking and re-checking until I got to 1.271 just like the factory one.

Yes I do understand that the deeper you seat the bullet, the less airspace their is inside the case and the greater the pressure becomes. But what is too deep?


Now what about those on a progressive? Do they really check after every "x" round like you do? Does factory ammo do that as well?

Is my OAL wrong? Should I be basing it on something else? Since I'm not touching my dies on my single stage press how/why would the bullet seating change?

I have the RCBS Rock Chucker with Hornady Lock n Load like this:
http://www.youtube.com/watch?v=eOl3H0hsjJM

So once my dies are set I don't have to change them just swap out.
-Jedi

 

[Broom_jm]

Jedi,

Your OAL results are remarkably consistent. IME, even when being cautious, it is unusual to see such little variance. I just checked 10 of my 380 rounds and had +/- .004" on them. If I were not so polite, I would call BS on your numbers.

I will put it like this: Load long enough and you'll discover that checking AS you load makes a lot more sense. Dies always stay right where you put them...until they don't

Reloading is one of those things that requires in-process QA...not spot-checking after the fact. I think you will find that guys who load using a true progressive press, or even commercial reloaders, check early and often. At the very least, don't you think it would be prudent to check OAL on the 1st, 5th and maybe 50th round? If you're going to have a problem it will usually happen early...which is when you want to catch it, right?

 

[shibumiseeker]

How critical your OAL is depends entirely on the powder and your load. Some powders get very scary when loaded hot and can be sensitive to seating depths. Other powders won't care at all. Personally I only obsess about OAL on my 10mm nuclear rounds. Remember OAL doesn't tell you seating depth which is what you really need to know. With my medium loads I don't worry about it at all.