Conflicting Load Data....


September 29, 2011, 11:59 AM
What to do about far conflicting Load Data?
Lets talk about 9mm Luger bcuz that is what I am loading right now and they have small-low volume case.
I am useing...
The latest Lyman 49th Edition manual:
9mm Luger cartridge,
115gr. JHP bullet,
Alliant Unique powder, Lyman shows a minimum charge of 4.4gr. up to 5.8gr. maximum.

From the latest SPEER #14 manual for 9mm Luger cartridge:
Same 115gr JHP bullet,
Same Alliant Unique powder. SPEER shows 5.6gr to 6.3gr.
That seems like a big diff. when useing such a small case. Doesn't it?
Same cartridge, same 115gr JHP bullet but the propellent will be
Alliant Blue Dot,
Lyman 49th manual shows a minimum charge of 6.8gr to 7.6gr max.
SPEER #14 shows 7.7gr to a whopping 8.5gr.
That is a big differance!
I don't think you can even get 8+grains of Blue Dot in a 9mm case!
Am I missing something here? Would you load 8.5grains of BD in a 115gr 9mm cartridge....and shoot it?

I'm loading hot bcuz I want to use my only 9mm handgun a CZ75 SPO1 to knock down steel popper targets.
Probably the 147grain boolits would be better for said application but I don't have any.
I just got 500, 115gr. JHP and 500, 125gr. JHP 9mm boolits and 1000, 230gr JHP .45 auto boolits all for $218 shipped & insured....and they aren't Montana Gold....they're Z E R O brand.

Do you guys like Zero brand bullets?

Thanks For Your Respons
Thanks For Your Time
charliemopic. . . . . . . a Norinco 1911 owner and like it!

If you enjoyed reading about "Conflicting Load Data...." here in archive, you'll LOVE our community. Come join today for the full version!
September 29, 2011, 12:18 PM
Zero bullets are good stuff, and on your load data, start low and work up. The age of the book, componets tested, all have something to do with the wide variance of data.

September 29, 2011, 12:20 PM
The difference is likely HP design and seating depth. What bullets are Lyman and Speer using in their data? Which one is closer in design to your ZERO?

September 29, 2011, 12:28 PM
What does the Alliant web site show? Since they do the pressure testing and bear the most liability, I would start there

Steve C
September 29, 2011, 02:08 PM
One of the reasons for differing data is that Lyman does not make jacketed bullets so they generally develop data using Hornady's while Speers data uses their bullets and other components. Different sources of data will likely use different primers and primers will make a difference in pressures.

It is incorrect to assume that the manuals load to the same maximum pressures, all they will generally say is that their data is less than SAAMI maximum so unless they are publishing their pressur data you have no idea if they are loading to the same level. What they do is generally load to the most accurate level with the powder combination and set the max value at the point where pressures become a bit erratic or accuracy drops off with their particular component mix.

It is a good idea to check several different sources for data and approach maximum levels with caution working up to those levels.

September 29, 2011, 02:15 PM
Look very carefully at the OAL differences between the different listings, and measure/compare the seated shank depths before deciding which manual to go with.

September 30, 2011, 05:08 AM
Great small book on this is One Book/One Calibre books published by Loadbooks for six bucks or so. Gives 1380 different loads for 9mm, Use this and some common sense , discard loads that look extreme and you should be fine.By the way many books load 9mm very short -under 1.100 that keeps pressure on the high side for that bullet.Most military fmj is loaded around 1.13 to 1.162 so this will reduce pressure if used with short bullet data.

September 30, 2011, 10:42 AM
Differences in published load data most likely come from different case, primer, OAL, test barrel length, test barrel groove diameter, bullet type and nose profile (ogive) used (Lyman #49 used .401" groove diameter barrel for their testing with .400"/.401" diameter bullets instead of the typical .400" groove diameter test barrel).

Sum of these variations can result in different chamber pressures they used to average max pressures and publish their load data.

For this reason, unless I can duplicate the load data components exactly, I give myself some buffer head room and use mid-high range load data with powder manufacturer's published load data as reference.

October 1, 2011, 11:44 AM
CAUTION: The following post includes loading data beyond currently published maximums for this cartridge. USE AT YOUR OWN RISK. Neither the writer, The High Road, nor the staff of THR assume any liability for any damage or injury resulting from use of this information.

When I started relaoding ~ 12 years ago, the first thing I did was to work up overloads with all powders and all bullets in 9mm to see what happens.
I stored the data in a spread sheet.
I show that only 7.4 gr Unique will fit with 115 or 124 gr bullets and both loads are wimpy.

Looking at Quickload, it shows 124% fill ratio with 7.4 gr and 115 gr. That is defiantly a compressed load.

Speer 13 shows 6.3 gr
Lyman 47 shows 5.7 gr.


I got 9.7 gr Blue Dot to fit under 124 gr, and it was still wimpy.

If you enjoyed reading about "Conflicting Load Data...." here in archive, you'll LOVE our community. Come join today for the full version!