Red Ryder Posted February 26, 2011 Share Posted February 26, 2011 (edited) Here is my data for all to comment! XDM 9mm 4.5 inch barrel. Titegroup 4.22 grains. Montana Gold 124 CMJ, Federal Pistol primers. Mixed range brass. Outside Temp 40 degrees. COL 1.147 - 1063.1091.1105.1084.1094.1078.1087.1105.1087.1074 Power Factor 134.7SD=10 Average 1086 COL 1.148 - 1048.1085.1104.1097.1089.1093.1099.1080.1084.1090.1082.1082.1092.1093. 1084.1083.1088.1105.1107.1083 Power Factor 134.2 SD=12 Average 1088 COL 1.149 - 1074.1102.1106.1089.1083.1089.1097.1091.1097.1096.1067.1089.1091.1105. 1090.1087.1083.1079.1089.1094 Power Factor 135.6 SD=9 Average 1089 COL 1.150 - 1066.1088.1088.1068.1098.1076.1101.1085.1076.1094.1073.1073.1094.1091. 1077.1079.1067.1088.1090.1093 Power Factor 135.5 SD=10 Average 1083 COL 1.151 - 1077.1090.1094.1090.1083.1099.1081.1080.1084.1082.1060.1086.1085.1088. 1070.1073 Power Factor 133 SD=9 Average 1082 COL 1.152 - 1071.1081.1106.1076.1111.1089.1087.1097.1067.1072.1077.1086 Power Factor 134.6 SD=13 Average 1085 COL 1.153 - 1079.1092.1086.1096.1101.1069.1086.1074.1087.1090.1067.1069.1085.1078. 1070.1077.1075.1066.1095.1082 Power Factor 134.1 SD=10 Average 1081 COL 1.154-1.155 - 1086.1107.1092.1083.1084.1086.1070.1078.1068.1079.1074.1089 Power Factor 135 SD=10 Average 1083 COL 1.160 to 1.163 - 1048.1079.1081.1081.1079.1051.1068.1065.1063.1078.1073.1077 Power Factor 133.5 SD=11 Average 1069 From this data, can we safely say that COL deviation from the 1.147 to 1.163 range in relation to Power Factor is minimal? Now I just need to find out which COL is most accurate!!! How does my data match up with yours??? Edited February 26, 2011 by RobAckerman Link to comment Share on other sites More sharing options...
Jman Posted February 26, 2011 Share Posted February 26, 2011 Well done !!! Yes, from your data the OAL was not effecting velocity to any great degree. Still, I like loading as long as I can (Glocks) and did for my XD's when I was shooting them. Your mags are the limiting factor there. Which one did you and your gun like? I'd say they're all going to be acceptable in the accuracy dept especially if your is a game gun. Pick one and try wearing it out Good luck with that. Jim Link to comment Share on other sites More sharing options...
Red Ryder Posted March 1, 2011 Author Share Posted March 1, 2011 Thanks Jman. But does my data match yours? Is it correct? Link to comment Share on other sites More sharing options...
Red Ryder Posted March 1, 2011 Author Share Posted March 1, 2011 Thanks Jman. But does my data match yours? Is it correct? Is my conclusion correct? Finally.....how does COL affect accuracy? Link to comment Share on other sites More sharing options...
punxsutawn Posted March 1, 2011 Share Posted March 1, 2011 Very nice detail. Curious which chronograph you used? thanks! Link to comment Share on other sites More sharing options...
Jman Posted March 1, 2011 Share Posted March 1, 2011 Thanks Jman. But does my data match yours? Is it correct? Is my conclusion correct? Finally.....how does COL affect accuracy? Your data is consistent with published Hodgdon load data. That's the only "matching" you need to concern yourself with. And yes, from my old XD notes, similar load data is consistent with yours. The tiny variations in your OAL will have negligible effects on accuracy. A properly assembled round with a good bullet like you're using will deliver all the accuracy needed. Pick one that runs the gun 110% of the time and practice till yer hands bleed. Jim Link to comment Share on other sites More sharing options...
Red Ryder Posted March 1, 2011 Author Share Posted March 1, 2011 Chrono was a borrowed one. CED chrono, old style. I shot my loads today (That sounds bad, but I'll go with it). I had no problem hitting bullseyes at 35 feet. Link to comment Share on other sites More sharing options...
Jman Posted March 1, 2011 Share Posted March 1, 2011 Chrono was a borrowed one. CED chrono, old style. I shot my loads today (That sounds bad, but I'll go with it). I had no problem hitting bullseyes at 35 feet. Agreed...it does. Sounds like you're good to go. Link to comment Share on other sites More sharing options...
farmrboy Posted March 2, 2011 Share Posted March 2, 2011 Wow! How long did it take do do all that? Good info. I bought a chrono last week and look forward to using it as soon as I get some good weather on a weekend. Link to comment Share on other sites More sharing options...
Erik S. Posted March 2, 2011 Share Posted March 2, 2011 Well done! Seems like the variation in COAL would do more for pressues than your results indicate. That is based on discussions here about pressure issues when loading too short. Would be interested to read your results if you pushed the envelope a bit on the short COAL and see what happens to your velocities/pressures. We could then put some data to the theory. Then again, we're only talking about .001" increments so may not see a noticable difference with the comparatively vast variation in MV using mixed range brass. I'd say your SD is good considering! Link to comment Share on other sites More sharing options...
Red Ryder Posted March 3, 2011 Author Share Posted March 3, 2011 The purpose of chronographing the above loads in .001 increments was to see if the normal variences in COL I get when reloading on my Dillon 650 with range brass, EGW U die, Redding seater die, and Lee factory full length taper crimp die affected my Power Factor to any degree which might cause me to be below power factor. My normal varience is +/- 3 thousands When attempting 1.150 COL. It did not. It is a well known fact that running very short COLs with near max powder charges is the opposite in a 9mm. Power Factor can increase exponentially with increasingly shorter COLs, eventually blowing up your gun.I'd rather not test that theory. Maybe when I am older and retired and bored! Link to comment Share on other sites More sharing options...
Red Ryder Posted March 3, 2011 Author Share Posted March 3, 2011 Wow! How long did it take do do all that? Good info. I bought a chrono last week and look forward to using it as soon as I get some good weather on a weekend. It took roughly 2 hours at the range, standing in a mud puddle surrounded by melting snow. I didn't wait for good weather. Link to comment Share on other sites More sharing options...
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