pewpewpew03 Posted December 9, 2018 Share Posted December 9, 2018 i have a mark7 650 pro Lee seating and crimp die 125gr gallant coated lead bullet mixed cleaned range brass my target is 1.165 and most come in a 1.163-1.165 but then I get some that are 1.171 and its absolutely driving me nuts..... 29 round test batch 5 were too long at the 1.17 mark.... ive checked shell plate, cleaned the die, readjusted the die, measured a handful of projectiles and they all are within .003 Any suggestions? Link to comment Share on other sites More sharing options...
Sarge Posted December 9, 2018 Share Posted December 9, 2018 21 minutes ago, pewpewpew03 said: i have a mark7 650 pro Lee seating and crimp die 125gr gallant coated lead bullet mixed cleaned range brass my target is 1.165 and most come in a 1.163-1.165 but then I get some that are 1.171 and its absolutely driving me nuts..... 29 round test batch 5 were too long at the 1.17 mark.... ive checked shell plate, cleaned the die, readjusted the die, measured a handful of projectiles and they all are within .003 Any suggestions? What powder? Compressed load? Compressed loads will lengthen on there own. Lubing cases? Lubing cases decreases variations significantly. Sort brass by headstamp. Oal is more consistent within same headstamp. Link to comment Share on other sites More sharing options...
MemphisMechanic Posted December 9, 2018 Share Posted December 9, 2018 A range of .009” or so was always unavoidable for me with factory toolhead and shellplate. Shorten it up so your long ones are short enough to chamber, make sure your pressures are good, and run with it. Link to comment Share on other sites More sharing options...
AHI Posted December 9, 2018 Share Posted December 9, 2018 You know there are multiple threads on this subject. All progressive presses do this. There are tangs you can do to minimize this. End result get over it. Adjust your seating die so that the long rounds are not to long and short ones are not to short. Some of the veneration is in your brass some in your bullets. Link to comment Share on other sites More sharing options...
pewpewpew03 Posted December 9, 2018 Author Share Posted December 9, 2018 9.5 gr of aa7 Brass lube lubed cases If i shorten the long ones down the 163-165s will be below 1.160 and being that its major i dont want excessive pressure spikes Link to comment Share on other sites More sharing options...
Kixx Posted December 9, 2018 Share Posted December 9, 2018 Ive found brass head stamp has a lot to do with it. I’ve taken to using one or two head stamps I know are consistent for major matches and the rest for locals/practice. Link to comment Share on other sites More sharing options...
GrumpyOne Posted December 9, 2018 Share Posted December 9, 2018 The biggest question is, do those at 1.171 still fit in the mags and chamber in the gun? If so, rock on, no changes necessary. Link to comment Share on other sites More sharing options...
pewpewpew03 Posted December 9, 2018 Author Share Posted December 9, 2018 the 171s after crimp etc did acutally plunk and spun in the barrel....so i have 50 more rounds now....same seating die setting varying from 1.160-1.171 Link to comment Share on other sites More sharing options...
GrumpyOne Posted December 9, 2018 Share Posted December 9, 2018 Well, there you go. Now, go see if they go bang and hit what you want them to hit. Link to comment Share on other sites More sharing options...
highhope Posted December 10, 2018 Share Posted December 10, 2018 if passed the plunk test, just shoot them... Link to comment Share on other sites More sharing options...
Hi-Power Jack Posted December 10, 2018 Share Posted December 10, 2018 3 hours ago, pewpewpew03 said: If i shorten them, they will be below 1.160 and I dont want excessive pressure spikes I've loaded 9mm Major down to 1.145", but not with 9.5 gr AA7 - if you can seat the bullet, it's okay. But, as you said, if the long ones pass The Plunk Test, you are good to go. Link to comment Share on other sites More sharing options...
racer-x Posted December 10, 2018 Share Posted December 10, 2018 I recommend that you determine what the max OAL is for this bullet in your chamber. Make a dummy round that is extra long - say 1.200 as a start. Plunk test it and gradually reduce the OAL of your test round until it just passes. Then you know what your OAL needs to be under 100% of the time in your gun. You might find out your chamber is throated longer than you thought and your 'long' loads aren't even close to being a problem. AA7 is a very slow powder and forgiving powder (slowest powder widely used for 9 major). Shortening your OAL from 1.165 to 1.145 is not extreme at all. You may need to drop .1 grain to maintain the exact same PF. Chrono to be sure and look at your primers for increased pressure signs. I normally load at 1.165 as well, but recently experimented with 1.145 OAL loads and MG115JHP's. Dropped my charge from 10.8 to 10.7 AA7 for the same PF. Primers looked the fine - same as longer loads. Accuracy of shorter loads was definitely not as good in my gun. If you play with shorter OAL's in a gun throated for long loads, you need to shoot some groups off a bag to ensure you accuracy is still what you want. Link to comment Share on other sites More sharing options...
Sneexies Posted December 10, 2018 Share Posted December 10, 2018 I used to have the same issue until I started bundling headstamps. Link to comment Share on other sites More sharing options...
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