Am I looking at this wrong? (Quick sizing question)

[8mmFan]

Good Morning Everyone. I hope everybody had a great Independence Day. Among other activities my sons and I celebrated by casting up a bunch of Lee 8mm 170 RN’s for the Mausers and some Lee .45 RN’s for the 45’s.

The metal was just mixed plumbous (sp?) mystery lead. Different stuff mixed in from the bottom of a seaport, pure lead from eBay, some wheel weights, and recycling-center mystery lead.

All bullets were water quenched (dropped in a pan of cool water), as has every bullet I’ve ever cast.

My question is this: the Mauser bullets all measured .322” after they were run through the LEE sizer, which is supposed to be .323. The aluminum gas checks weren’t even a full .323”, they were JUST barely over .322”. So am I measuring this all wrong? It probably doesn’t make a difference: I’VE NEVER PUT THE CALIPERS ON ANY OF MY BULLETS BEFORE, and my cast experience has been “fine.” Generally never shot 5-shot bug-hole groups with most loads but certainly acceptable accuracy.

Now, admittedly, my calipers are not the ultimate in caliper technology - just a nice plastic caliper that I bought at Menards maybe 20 years ago. But it seems to have stood the test of time and not broken. It wasn’t a $2 caliper.

But am I looking at the wrong thing to measure? Shouldn’t these bullets come out at least at .323”. Isn’t that the point of a cast bullet?

Just checking for my general knowledge.

Thanks,

8mmFan

P.S. When I sized the .45 RN’s, a LOT of them just slid up into and through the LEE sizer with almost no resistance whatsoever. Some had some of the tumble-lube groooves affected (sheared a tiny smidge) but some didn’t.

[Gatch]

Plastic callipers at best are a guessing stick. Even a decent brand is not precise when talking +-0.001".

Beg/borrow/buy a decent micrometer and check your callipers against it.

[alamogunr]

Go with Gatch's suggestion. A decent micrometer will set you back some decent $$, but will give you decent information. Even a good set of calipers is not accurate enough to measure boolit diameter to .001".

Relegate your plastic calipers to OAL measurement and even then don't rely on it too much.

[8mmFan]

Ah. Thanks for the tips, guys. That makes sense.

[Rcmaveric]

Lee push through sizers are notoriously off aswell. Once you have a reliable measuring device, just polish out the lee sizer a smidge if needed. Doesnt take much.

Sent from my SM-G950U using Tapatalk

[country gent]

A good used 1" micrometer isn't all that expensive ( $20-$35) and are way ahead of calipers in accuracy.

As to your bullets if they've been working and no issues I wouldn't worry to much. I would lube size and shoot. If you have some from a previous session batch measure a few of those to see where they were.

[MostlyLeverGuns]

A decent stainless steel dial caliper covers most gun/reloading work with very good accuracy, half a thousandth (.0005) anyway. Too much flex, wear, and temperature change to plastic calipers. A decent stainless metal caliper is $30 to $60 with the best, Starrett - $91 on Amazon. I have a digital Mitutoyo but prefer the my dial calipers. The digital can be zeroed to different values for measuring tolerances, using the headspace tools like Hornady and other gauges. I have several of the less expensive models on different benches to keep from chasing them. Micrometers can be slightly more accurate but are limited to a specific range, 0-1", 1"-2". For measuring to a tenth (.0001) you need a micrometer, but mostly a decent caliper will do fine and handle 0" to 6". A good caliper is more than accurate enough to measure bullet diameter.

[8mmFan]

Thanks guys. I’m going to get a decent micrometer. I should have one around the house, anyway. When we’re talking about a game where thousandths of an inch can make a difference, well...best to be able to measure it.

I’ve also held off ordering some new molds that might better fit an old 7x57 I’ve got. I want to be able to measure the slug accurately to get what I think is probably going to be a necessarily slightly over-size mold.

[redhawk0]

The last set I bought on ebay was a Scherr Tumico 0-1 Micrometer. I paid $15.50 for it last year. ST is a good brand...they were a contractor for the military "corp of engineers" back in the day. I have two sets...one is marked 1942 I believe it was. Extremely accurate and when purchased used...they aren't that much. Starrett are also excellent but you will pay up for them. (probably paying for the name...IMHO)

just another option.

redhawk

[mdi]

Hmmm. Every Lee bullet sizing die I own has been within .0005" of the diameter that was stamped on the side. But I only have purchased 3, 44 caliber dies, one 30 caliber die, 2, 35 cal, and two 45 caliber dies. All bullets I have run through the dies started out larger than the ID of the die and emerged within the stated diameter of the die. Alloy makes a difference and I have experienced some "spring back" with some harder alloys...

Calipers aren't good for measuring bullets because of their construction; long, narrow jaws that can flex and can be difficult to read if there is any variation in the measured surface. Micrometer spindles and anvils are wider and the "screw action" is easier to use on small round items.

I have worked with precise measuring tools most of my life and yep, good mics are pretty expensive, but my latest 1" mic is a Lyman (don't know who made it), but it has carbide tips and is smooth and accurate to .0005" which is good enough for home shop use. IIRC they were well under $50.00. My "good " Starret, Mitutoyo, and Brown and Sharp tools were stolen. Craftsman dial calipers and micrometers are good quality at a more affordable price...

[RED BEAR]

I have to say that a good caliper should be accurate to +or - .001 a micrometer should be accurate to less than + or - .0001. A cheap set of either is anybody's guess.
And .001 can make a difference.i size mine .325 . Lee sizers are easy to open up .

[8mmFan]

MDI - don’t get me wrong: I wasn’t looking to toss mud at LEE. I was looking to see if I was legitimately misunderstanding my process or results. I have had literally, NOTHING ever go wrong with a LEE piece of equipment that wasn’t user error. And I’ve pretty much only used LEE equipment for all types of loading (other than MEC for shotgun) for over twenty years.

All of the answers in this thread are basically pointed at what I looking for: where Yours Truly was going wrong.

8mmFan

[8mmFan]

I just bought a Scherr & Tumico 0-1” used micrometer on Evilbay for $19. I will report back on this thread, once I get, with the measurements that it gives on these bullets.

Thanks guys.

[redhawk0]

I think you'll be happy with the S&T. I have two of their mics. One is for measuring tube wall thickness (has one curved anvil for the inside of the pipe/tube)...the other is a flat/flat anvil for measuring outside diameters like the pipe diameter, boolits, bullets, wire...etc.

at $19...you done good.

redhawk

[bedbugbilly]

I certainly can't add to what has already been said. All I can say is what my experiences are. I use a 323 Lee push through sizer as well for my old 1907 Danzig GEW98. I have the same mold as you do probably (Lee GC). The bore of my rifle slugs out right at .323 - measured with a micrometer. The throat in my Mauseer is tight and I have tried a number of different bolts out of it and still have to size them to 323 - I think 324 would be about max for the rifle. I usually like to have a boo lit .002 oversize but things are what they are.

Anyway - I have a decent set of digital calipers but I am often surprised at how much they can be "off" when doing a quick diameter check on a boolit. I have used GC boolits in my Mauser and they shoot fine - I don't push them hard and have never had any leading problems. I much prefer to shoot light loads out of it and have two boolits - one out of the RCBS .323 Nambu mold - they drop at .323 - they are around 122 gr IIRC. The other mold is a NOE 135 ing grain RNFP that was a special run - it is a .326. When I bough it, I figured I would polish a lee push through sizer to .325 and they would be great - not so much. I have never done a chamber cast but that's when I found out that the throat was on the tight side - they dropped at about 326 to 327 and I had to ice them down - I borrowed a sizer and got the to 324 and they worked O.K.

I'm sure you will be pushing yours faster than i do - and I forgot to mention that I tumble lubed them all in paste wax / aloe. Anyways - they shot just fine and for my shooting at 50 yards or so - all of the worked pretty well and with playing with the powder loads - Red Dot - I could get the groups to tighten up. I wasn't looking to put the all int he same hole - just enjoy shooting the "old girl".

I hope you'll post on how well yours shoot out of your rifle as that will be the test. While your calipers show them at 322 - you might be pleasantly surprised.

I cast some 358-158 flat noses up the other day in a Lee 2 cavity for my new 357 rifle. After doing a pile of them I grabbed my digital calipers to check them - my enthusiasm dropped quickly when they measured out at .357 - what??? I'm not going to push them hard and will shoot "as cast" - but I couldn't believe what I was reading on the calipers and I zeroed them in a number of times and kept measuring. I had a bag of 1X fired 357 cases on the bench so I grabbed a couple, thinking they would be an easy push into the mouth - nope. I got my micrometer out and measured several times and my caliper measurements were off .0015. I have a set of q" Starret micrometer and a Sears Craftsman 1" that I have had for fifty years - surprisingly, the set of Craftsman micrometer has always proven to be the most accurate - it has a nice "clutch" on the thimble so measurements can be consistent and it always zeroes in.

A good used 1" micrometer really doesn't cost a lot and keep your eyes open and you'll run across one. Lots of times I've seen them at flea markets.

Let use know how your boolits shoot in your rifle though and hopefully they will shoot just fine for you. My old Mauser keeps surprising me as I figured I would have a leading issue with .323 but the bore is as clean of lead as can be after putting rounds through it.

[nicholst55]

Old machinist joke: vernier calipers = 'very-near' measurement.

[Gatch]

Old machinist joke: vernier calipers = 'very-near' measurement.

Foreman at the start of my apprenticeship said my $400 coolantproof mitutoyo verniers was the most expensive guessing stick he's ever seen, that they're as good as a fabricators tape measure and the minimum standard for measurement is a properly calibarated CLEAN micrometer. Hard bugger, but had high standards.

[8mmFan]

HaHa. Good laughs on these last two posts.

BedBugBilly - I will be happy to post some of the results with these bullets. I might have stated earlier - I’ve used this mold and these bullets before, and they do just fine. Nothing spectacular, but certainly 1.5 - 2.5 MOA at 100 yards and pretty tight at 50 yards. I was just surprised by what my calipers were showing me for a bullet diameter on the bullets. I realize now that my calipers probably aren’t precise enough.

My 8x57’s are Yugo M-48B’s. They have proven to be good rifles over many years. You’d be shocked at what they’ll do with 180g Nosler Ballistic Tips.

My interest in shooting lately has run to the “cat’s sneeze” line of things because now my sons are big enough to handle these rifles, but not with full-power loads. The cat’s sneeze loads allow them to learn the big rifles, hold them, shoot them, get to know them, without getting beaten up and developing a flinch.

8mmFan

[Oily]

Did you have good resistance when you sized the boolits or did they just sail through? If they sailed through it might be your alloy.

[Wayne Smith]

Short of a good set of mikes the easiest way to measure a boolit is simply to drop the nose of it into the muzzle of your rifle. If it falls through it is too small, if it stops and chambers you are good to go.