My jump into reloading after 55 years

[GreyGeek]

so accurate measurement at the ogive requires an adapter for your calipers.

Oh, I see what you are saying ... measuring from the base of the bullet to where the seating die touches the bullet.  I don't know how I  could determine just where on the ogive the seating die touches with even an accuracy of 0.01", to say nothing of 0.001".   I guess just measuring from the base of the cartridge to the tip of the bullet, as an expression  of the OAL, would at least make sure the bullet can clear the clip and enter the chamber properly.  The test rounds I have fired cycle smoothly and eject nicely, but if noise and recoil are any measure, and that is just another "feel" measurement, the 4.1gr shells are at the upper end of the pressure range for the Nano.  I'll be watching for flattened primers and bulging cases.

[Dan W]

Do you realize that most modern 9mm handguns can safely fire +p  and +p+ ammunition that has pressure far exceeding SAAMI max?

And I doubt most published reloading data exceeds even the 35,000 psi limit. I am not suggesting you ignore the recoil and ejection characteristics , but a chronograph would be very helpful in determining when approaching the max by comparing the velocity of your handload vs the expected velocity of the published data.

What am I getting at? I don't worry so much about exceeding SAMMI max pressures when I know my Glocks can take it. That being said, I do not really like the extra recoil, flash and noise of max loads, so I rarely go there.

The Sporting Arms and Ammunition Manufacturing Institute (SAAMI) has set a pressure ceiling for standard pressure 9mm Para at 35,000 pounds per square inch (psi). By contrast, NATO pressure ceiling is 42,000 psi. In-between U.S. standard pressure 9mm and NATO spec, we have two options. 9mm +P has a SAAMI pressure ceiling of 38,500 psi. There’s no SAAMI spec for 9mm +P+; that’s just a way of saying its pressures exceed +P standards. …

[SS_N_NE]

I don't believe that anyone can accurately measure COAL within .001" unless you are measuring from the ogive and not the tip of the bullet, because the bullets are just not that precisely made

I hadn't really thought/worried about 9mm bullet seating too much. I mess around with my .45acp loads quite a bit with different bullet shapes. The Lee seating die for .45acp is rather flat and really only hits the tip of the bullet. Seating is usually very consistent.
I pulled the seat punch out of my Lee 9mm die tonight and noted it has a significant cone (actually looks like it was drilled with a 60 degree center drill typically used for machine work to drill lathe centers). Putting number of Winchester 115 grain FMJ flat base into the punch I got variations of up to .006"  with .003" variance the most common. Only tried some 20 bullets. Just doing some dirty testing, there was slight variation in the tips of the bullets (guessing different swag dies?). Since the tip of the bullets touch a 60 degree cone and bullets have slight variation at the point of contact it explains a lot of why OAL can vary by such an amount.

[Dan W]

Yes, seater die mismatches  can have a big impact on consistent COAL. I think one company will even make you a custom seater plug (RCBS?)

[GreyGeek]

Do you realize that most modern 9mm handguns can safely fire +p  and +p+ ammunition that has pressure far exceeding SAAMI max?

So, you're saying that the following warning in my Nano manual is just the usual CYA stuff?

WARNING: The extended use of +P or +P+ ammunition may decrease component part service life expectancy. DO NOT use sub-machine gun ammunition because the chamber pressure may reach or exceed proof load pressure. Lead bullets have a tendency to cause bore leading, which may dramatically increase the discharge pressure.

Be sure to remove all chamber and bore lead accumulation after each use. DO NOT shoot cartridges with jacketed bullets through a barrel previously fired with lead bullets before the bore is thoroughly deleaded.

[abbafandr]

So, you're saying that the following warning in my Nano manual is just the usual CYA stuff?

From I understand a majority of smaller pistols like the Nano, PF9 etc aren't designed to digest the +p like a full size Smith & Wesson, Glock, Springfield, ad nauseum.   But again not an expert.

[Dan W]

So, you're saying that the following warning in my Nano manual is just the usual CYA stuff?

NO, what I am saying is your  OCD is flaring if you are worrying about .002" COAL

[GreyGeek]

OCD is flaring

Oh.  Well, that's a distinct possibility.    I've always been OCD for accuracy, which is why Bradford Labs made me their trainer for the entire oil field region in South West Texas.

But, 9mm dimensions being what they are, there isn't that much room to work with.

BTW, I measured the distance from the edge of the chamber to the beginning of the lands.  0.601"  There is a distinct shelf there and when I stick an empty but sized cartridge into the chamber it comes to a definite stop against that ledge, leaving just enough shell protruding to allow the extractor a space to grab it.

Considering what you said  about the ogive, it appears to me that the lands "touch" the ogive exactly where the ogive meets the casing, for a JRN  bullet.

I  found this posting, which is the first of six on reloading: http://www.czfirearms.us/index.php?topic=31914.0
Nice read.

[SS_N_NE]

The 9mm Luger cartridge headspaces on the mouth of the casing. The case should be close to .380" diameter at the casing mouth. The bullet at the mouth is .355" (or so). Since the ogive starts at the mouth of most seated bullet styles, it is doubtful that your bullets are hitting rifle lands when chambered. Best way to tell would be to measure depth of a dummy cartridge (bullet seated to your intended COL) chambered in your barrel to the muzzle of the barrel. Them drop a free bullet into the chamber against the lands and measure that dimesion again. Easy to do with the barrel stripped from the firearm (and safer practice even though dummy ammo is used). It is useful to know a relationship of how far a bullet starts from a seated position on the casing to the rifling lands.

I have noticed change in accuracy by playing with .45acp by altering the dimension from seated to rifling.  Can't say I have found any appreciable differences in my 9mm loads yet.

[SS_N_NE]

Just measured some Winchester white box 115 gr. 9mm Luger and found COL of 1.149" to 1.162" in just 10 rounds. The average guy accepts that whatever in the box works with his gun...and it usually does.

[GreyGeek]

Them drop a free bullet into the chamber against the lands and measure that dimesion again

Good idea!   Thanks!

[GreyGeek]

found COL of 1.149" to 1.162" i

Wow! I wouldn't have suspected that commercial ammo would vary  that much.   Now I am wondering how much variance there is in match grade ammo?

It's starting to give me the feeling that just slapping the stuff together and keeping the powder under max is all one needs to do.  (But years of training would prevent me from being that sloppy.)

[gsd]

Wow! I wouldn't have suspected that commercial ammo would vary  that much.   Now I am wondering how much variance there is in match grade ammo?

The match grade stuff I load for my 308 has a OAL of 2.73-2.74. I mic every 10th round.

[GreyGeek]

Thanks for the loan of the LEE Powder measuring tool, gsd!

I did the comparison and noted that your device does not display the gap that mine does.  I've attached a jpg which shows the gap.  It at the point, and on either side, where the rotor barrel meets the circular black core of the device.  The  when the rotor barrel is rotated up to receive the next powder charge the gap is right where the little white wiper pad is, allowing powder to trickle past.  The powder falls to the bottom of the gap and when the tighter part of the barrel comes around it grinds the  powder, increasing tension and making the handle more difficult to turn.

In the  picture below I've marked the right side of the gap with red arrows and a line paralleling the gap.  It is the dark shadow to the left of the line.  As you can see, it proceeds on beyond the bottom red arrow and that is the part of the gap where most of the powder falls out.  In the course of reloading 100 shells I'd estimate that 10 - 15 grains of powder fall out.   The only way to minimize the powder falling out is to tighten the screw so  tight that it is almost impossible to crank the handle without using two hands on the device.

[SS_N_NE]

Lee has a pretty decent guarantee on their products. May be as well to spend the shipping and get a replacement.

[GreyGeek]

Well, my calibration for  weights and  caliper came in a couple days ago and I checked my balance and calipers.  The calipers is right on.

I massed a series of weights from 1 mg to 5.7 grams and collected data points.  I entered them into the solution for a Least Square Linear Regression to determine the function which best matched the data points.  Here is the results:

actual mass = 0.999*mass reading  + 0.204

Just as I suspected, the scale at the lower end shows a value which  is lower than  the actual mass, and at the high end  of the scale they are much closer together.  So, when I was reading  "3.9" grains  of HP-38 on the scale it was actually 4.1 grains.  My "4.0" loads were actually 4.2  grains, which explained why they were so loud, recoil  was greater than  normal, and the casing was ejected twice as far as my  lighter loads or my commercial  stuff.  If I want 3.9 grain loads I'd have to mass it to 3.7 grains on the scale.   What I actually did was mass 10 charges (initially 20 but 10 worked well enough) on the scale and divide by 10 to see what a single charge would mass. I putzed with the 10 charges until my computed single charge was 3.87gr, which was as close as I could get to 3.9 gr.  Loading 100 rounds and checking every twenty my 10 charge mass was within 0.1 grains of 38.7 each time, so that is what I am going to continue to do.