Starting load data question

[Wildbillz]

Hi All
So I finished loading some ammo the other night and was getting ready to switch calibers. I was going to 9mm so I looked up the starting load in my Speer manual. Ok 4.0 of Win 231 to start with a 124grn TMJ, 4.5grn max. So I figure I will start at 4.2grns. Then I look in the Hodgdon manual and they list starting at 4.5grns (I don't recall the max as I don't have the books with me here)? Then I looked at the Winchster and Hodgdon websights and got even different numbers. I understand that the type of bullet used is going to change things a bit, but a FMJ should be the same no? Color me confused.

WB

 

[Mr_Flintstone]

There is often fluctuation between manuals, but after reading this, I'm interested too. My older Speer manual lists 4.0 - 4.5 gr as well, Lyman 48 lists 3.9 - 4.4, Hodgdon online lists 3.9 - 4.4 Lee #2 lists 4.2 - 4.5, Hornady Handbook #3 lists 3.9 - 5.2, and Hornady Handbook #4 lists 4.7 - 5.3. That's a lot of fluctuation, but most overlap in a significant portion. I'd go with the data from Speer, Lyman, or Hodgdon online. That Hornady Handbook #4 seems dangerously high.

 

[Zendude]

A little bit of COAL difference in 9mm can change pressure significantly.

 

[Blue68f100]

Also different test equipment. Some use a actual pistol most use a test chamber. So leads/lands are all over the place.

 

[Zaydok Allen]

A little bit of COAL difference in 9mm can change pressure significantly.

Different COLs was my first thought too.

I just started reloading 9mm and noted the plethora of load data, many of which use similar components but different charges. COL seems to be the biggest difference.

 

[BC17A]

Never forget the golden rule of reloading. Reduce 10% and work up, so 4.1 sounds like a safe place to start.

 

[Dudedog]

Some Chrono data, might or might not be helpful
S+P SP, mixed range brass, 5" 9mm 1911
Charges as thrown after setting measure

String: 3
Date: 10/29/2017
Time: 10:04:31 AM
Grains: 124
Hi Vel: 995
Low Vel: 962
Ave Vel: 986.2
Ext Spread: 33
Std Dev: 14
RMR 124 MPR JHP 4.0 HP38 1.08 5inch 1911
Velocity Power Factor Ft/Lbs
991 122.884 270.378
993 123.132 271.47
990 122.76 269.832
962 119.288 254.785
995 123.38 272.565

String: 2
Date: 10/29/2017
Time: 9:42:14 AM
Grains: 124
Hi Vel: 1068
Low Vel: 1004
Ave Vel: 1034
Ext Spread: 64
Std Dev: 24
RMR 124 MPR JHP 4.3 HP38 1.055 5inch 1911 (shorter OAL than above)
Velocity Power Factor Ft/Lbs
1046 129.704 301.222
1021 126.604 286.995
1004 124.496 277.518 This one messed up the numbers
1068 132.432 314.026
1034 128.216 294.35

String: 2
Date: 7/23/2017
Time: 10:44:23 AM
Grains: 124
Hi Vel: 1046
Low Vel: 1003
Ave Vel: 1026
Ext Spread: 43
Std Dev: 16
RMR 124 MPR-HP 4.5 HP38 1.08 OAL Longer OAL than above, .2gr more powder
Velocity Power Factor Ft/Lbs
1003 124.372 276.965 Another one that seems like the charge was a little light....
1036 128.464 295.49
1022 126.728 287.558
1025 127.1 289.248
1046 129.704 301.222

 

[LiveLife]

I understand that the type of bullet used is going to change things a bit, but a FMJ should be the same no? Color me confused.

There are different reloading variables such as bullet type (plated vs jacked), bullet diameter (.355" vs .356"), OAL/COL, primers, case used, etc. that will effect chamber pressures and start/max charges.

Speer load data for Speer 124 gr TMJ (Thick plated RN .355" diameter) - https://www.speer-ammo.com/download...m_caliber_355-366_dia/9mm_Luger__124_rev1.pdf

• Speer 124 gr TMJ W231 1.135" COL Start 4.0 gr (887 fps) - Max 4.5 gr (998 fps)

Hodgdon load data for Berry's 124 gr HBRN-TP (Thick plated hollow base RN .356" diameter) and Sierra 125 gr FMJ (Jacketed RN .355" diameter) - http://www.hodgdonreloading.com/data/pistol

(NOTE: Since many jacketed/plated bullets can vary by 1.0 gr, I often interchange load data for 124 and 125 gr 9mm bullets)

• Berry's 124 gr HBRN-TP 1.150" COL Start 3.9 gr (920 fps) 27,400 PSI - Max 4.4 gr (1,037 fps) 31,900 PSI

• Sierra 125 gr FMJ 1.090" COL Start 4.4 gr (1,009 fps) 24,600 CUP - Max 4.8 gr (1,088 fps) 28,800 CUP

So, depending on bullet type, sizing and OAL use, reference appropriate load data.

FYI, for most plated 124 gr RN bullets, I reference Speer TMJ (max 4.5 gr) and Hodgdon Berry's load data (max 4.4 gr) of W231. For most jacketed 124 gr RN bullets, I reference Hodgdon Sierra load data (max 4.8 gr).