"Determining safe powder load with reduced COL?"

[jell-dog]

Hi!
I have purchased a Springfield XDs 9mm 4" barrel pistol.
I am finding several good loads that I worked up for my Sig M11-A1 (P229) 9mm 4" pistol that will not plunk in my XDs.

Evidently the XDs needs a shorter COL for some of the bullets I have on hand.

I have found the working COL for these bullets with the XDs but they are 0.020" to 0.030" shorter COL than the COL's I used for the Sig.

I use 1.135" COL for 115gr plated/jacketed bullets and 1.140" COL for 124/125gr plated/jacketed bullets.

How do I safely determine the reduced powder range for these reduced COL loads?

Thank you,
JD

 

[Walkalong]

That's a tough one, but .030 will make a large difference. A chrono would help because there is no free lunch when it comes to velocity. Since you have a good one worked up for the other pistol, why not drop it down and work back up to that velocity using the XDs and see how they do?

 

[ArchAngelCD]

Good advice above from Walkalong. I will add, what OAL does the data you are using recommend. If the OAL is shorter than your OAL for the XD then you are good to go to at least the charge weight you are using when working up the new load.

 

[ants]

Yes, on both advice above (Walkalong and Archangel). I was going to write several sentences but they got here first.

What comes to mind is this: The relationship between OAL and pressure isn't linear. There's no formula, and you can't just assume it's a straight line and reduce by the numbers. Best to stick to published data as Arch suggests. Go ahead and work it up for both guns as Walk suggests.

Final thought: Perhaps some day you find a different bullet more forgiving in both guns' chambers, so you can stick to good published data and keep both guns happy with the same ammo. The bullet is a variable, keep it in mind.

 

[rfwobbly]

PM sent.

 

[mstreddy]

Hi Jell-Dog,

On thing to check besides the plunk test is the sizing of the cases. See if the sized cases plunk in the XD chamber. For my Lone Wolf Glock 17 barrel I have to size the cases very tight or they won't plunk. I'm loading various 124/127 Plated down to 1.12 to 1.13ish over a charge of Promo (Red Dot by weight). I'm also loading a 147 gr FN at 1.12.

What powder and charge are you working with?

 

[jell-dog]

mstreddy,
PM sent
JD

 

[rsrocket1]

Another thing to do is to take a cartridge that won't pass the plunk test in your XD and color it completely with a magic marker. Try the plunk test again. You may have to push the round back out with a dowel from the muzzle but try to gently push the round down just a little to ensure the ink will rub off.

Now check the round to see where the ink rubbed off. If it is on the bullet, you probably need to make some dummy rounds and see how deep you need to seat them. If it's on the case mouth, you may need to close the flare a bit with a taper crimp die. If it's at the base, you need a die that will size all the way down the case (most don't). If it is on the case where the bullet is seated, a Lee FCD will iron it out (don't do this with lead bullets or you may swage them down and get leading).

 

[hdwhit]

Walkalong wrote:
...but .030 will make a large difference.

Yes. To illustrate how large that difference can be, the Speer Reloading Manual #11 says this with regard to bullet seating depth and the effects of bullet set-back for 9mm Parabellum on page 385:

...loads that produced 28,000 cup went to 62,000 cup when bullets were purposely seated 0.030" deeper! Thus it is of utmost importance that bullets do not become deeper seated...

 

[Walkalong]

That is exactly what I based my comment on. I assume they mean for a full power/pressure load, so a lesser load wouldn't be as drastic, but still quite significant.

 

[vaalpens]

JD,

Congratulations with the new Springfield XD. Hopefully you are not selling your M11-A1.

I can't help much with 9mm change in COL, but in 40s&w I have changed between 1.142" and 1.125" and have some chrono data with similar powder loads. Following are the chrono results showing the differences I experienced. Hopefully this data will give you some idea.

40S&W, P229, 3.9"
COL: 1.142"
Xtreme, 165gr, RNFPHPCB, BE86, 5.9gr, CCI500
Average: 893
ES: 33
SD: 14.6
Force: 292
PF: 147
Velocities: 872, 885, 904, 905, 902

40S&W, P229, 3.9"
COL: 1.125"
Xtreme, 165gr, RNFPHPCB, BE86, 5.9gr, CCI500
Average: 920
ES: 41
SD: 15.7
Force: 310
PF: 151
Velocities: 896, 937, 928, 925, 914

Please note that the following data not just shows the COL change but also a different primer.

40S&W, P229, 3.9"
COL: 1.142"
Xtreme, 165gr, RNFPHPCB, PowerPistol, 6.7gr, CCI500
Average: 974
ES: 29
SD: 10.8
Force: 348
PF: 160
Velocities: 961, 990, 977, 977, 969

40S&W, P229, 3.9"
COL: 1.125"
Xtreme, 165gr, RNFPHPCB, PowerPistol, 6.7gr, WSP
Average: 1013
ES: 36
SD: 13.2
Force: 376
PF: 167
Velocities: 1017, 1013, 992, 1028, 1017

 

[LiveLife]

Adding to vaalpen's chrono data - https://www.thehighroad.org/index.p...g-oal-col-long-vs-short.819257/#post-10511700

Test loads shot from Glock 22 with KKM 9mm conversion barrel using Caldwell chrono:

- IMR Target 4.2-4.3 gr RMR 115 gr FMJ 1.155" OAL: 1036-1068-974-1044-1015 fps - SD 35
- IMR Target 4.2-4.3 gr RMR 115 gr FMJ 1.130" OAL: 1072-1045-1078-1059-1077 fps - SD 14

- Alliant Promo 4.1-4.2 gr RMR 115 gr FMJ 1.155" OAL: 1093-1027-967-1095-1126 fps - SD 64
- Alliant Promo 4.1-4.2 gr RMR 115 gr FMJ 1.135" OAL: 1102-1092-1072-1142-1144 fps - SD 31

 

[Dudedog]

Went to the range today so I ran a quick OAL ladder for you.
None of the loads are MAX or close to MAX (light to medium), no powder compression.
I would speculate if you were loading MAX loads the numbers would look different, OAL changes would be more pronounced. Powder compression due to a shorter OAL would have an effect as well. (or heaiver charge)
But for what it's worth

Springfield XD 4" Once fired WIN Brass S+B SP
Charges as thrown by Lee Auto Disk
Bullet Extreme 124 (125?) RNs
Lee FCD used lightly

String: 7
Date: 4/23/2017
Time: 12:57:46 PM
Grains: 124
Hi Vel: 947
Low Vel: 920
Ave Vel: 933
Ext Spread: 16
Std Dev: 10
Xtreme 124 RN 3.8 AA2 OAl 1.155
Velocity Power Factor Ft/Lbs
920 114.08 233.023
947 117.428 246.901
936 116.064 241.199
928 115.072 237.093
936 116.064 241.199

String: 9
Date: 4/23/2017
Time: 12:59:43 PM
Grains: 124
Hi Vel: 950
Low Vel: 931
Ave Vel: 943
Ext Spread: 19
Std Dev: 7
Xtreme 124 RN 3.8 AA2 OAl 1.14
Velocity Power Factor Ft/Lbs
931 115.444 238.629
945 117.18 245.859
950 117.8 248.468
943 116.932 244.82
948 117.552 247.423


String: 1
Date: 4/23/2017
Time: 1:00:56 PM
Grains: 124
Hi Vel: 959
Low Vel: 943
Ave Vel: 952
Ext Spread: 16
Std Dev: 5
Xtreme 124 RN 3.8 AA2 OAl 1.13
Velocity Power Factor Ft/Lbs
952 118.048 249.515
954 118.296 250.565
943 116.932 244.82
959 118.916 253.198
955 118.42 251.09

String: 2
Date: 4/23/2017
Time: 1:02:04 PM
Grains: 124
Hi Vel: 966
Low Vel: 936
Ave Vel: 952
Ext Spread: 30
Std Dev: 10
Xtreme 124 RN 3.8 AA2 OAl 1.11
Velocity Power Factor Ft/Lbs
936 116.064 241.199* This one skewed the numbers but charges as thrown I didn't weigh every one
955 118.42 251.09
951 117.924 248.991
955 118.42 251.09
966 119.784 256.908


-----------------------------------------

String: 1
Date: 4/23/2017
Time: 12:50:35 PM
Grains: 124
Hi Vel: 1065
Low Vel: 1038
Ave Vel: 1056
Ext Spread: 27
Std Dev: 11
Xtreme 124RN 5.0 BE86 OAl 1.155
Velocity Power Factor Ft/Lbs
1038 128.712 296.632
1064 131.936 311.678
1065 132.06 312.264
1062 131.688 310.508
1055 130.82 306.428

String: 2
Date: 4/23/2017
Time: 12:52:05 PM
Grains: 124
Hi Vel: 1084
Low Vel: 1061
Ave Vel: 1072
Ext Spread: 23
Std Dev: 9
Xtreme 124RN 5.0 BE86 OAl 1.14
Velocity Power Factor Ft/Lbs
1071 132.804 315.793
1079 133.796 320.528
1067 132.308 313.438
1084 134.416 323.506
1061 131.564 309.923

String: 3
Date: 4/23/2017
Time: 12:53:05 PM
Grains: 124
Hi Vel: 1092
Low Vel: 1056
Ave Vel: 1072
Ext Spread: 36
Std Dev: 15
Xtreme 124RN 5.0 BE86 OAl 1.13
Velocity Power Factor Ft/Lbs
1058 131.192 308.173
1084 134.416 323.506
1056 130.944 307.009
1070 132.68 315.203
1092 135.408 328.298

String: 4
Date: 4/23/2017
Time: 12:54:31 PM
Grains: 124
Hi Vel: 1089
Low Vel: 1052
Ave Vel: 1076
Ext Spread: 37
Std Dev: 14
Xtreme 124 RN 5.0 BE86 OAl 1.11
Velocity Power Factor Ft/Lbs
1089 135.036 326.497
1076 133.424 318.748
1084 134.416 323.506
1052 130.448 304.688
1080 133.92 321.123

In hindsight I should have weighed all the charges. A couple of the BE86 #s in the 1.13 and 1.11 groups look low.

 

[jell-dog]

Dave,
Thank you for your work!
I have both X-Treme 124 RN and BE-86, so will see what COL works in the XDs.
Which COL was a light shooting target load?
Thanks again!
Mark

 

[jell-dog]

PS
I also have AA#2

 

[earplug]

Had the same issue while working up a light home made Powder coated cast bullet 9 MM load. first load was as long as it would plunk and listed starting load. My pistol likes longer cartridges OAL for reliable feeding. They ran a bit light based on the ejection pattern and lack of slide lock working on known magazines. I bumped the charge 1/10 of a grain and had perfect ejection and slide lock operation. Had a little hiccup with fully chambering two rounds. A build up of Powder coat on the bullet ogive I suspect.
My home made PC cast bullets lack the quality control of factory FMJ's so I had two failure to completely chamber. Changed the seating depth about 20 thousands and reduced the charge weight by 1/10 of a grain. The last 75 rounds have run perfectly.
This is the type of cause and effect you might experience when working up loads with your pistols.
Keep good notes. Realise what might effect pressure when making changes have fun.

 

[Dudedog]

Your welcome JD.
All the AA#2 loads were close to start charge, nice and light but would not make 125 PF if that matters.. Had a few extras @ 1.13 and they seemed to shoot well. Unless you are after light I would say bump the load up from 3.8 to maybe 4.0gr. (Western has a bunch of different charge ranges for various 124s in 9mm)
3.8 functioned fine in my XD and my 9mm 1911 @ 1.13 (what I would normally load the Xtremes at)