mnpfamily

Thanks for the help, I appreciate it. I did check out that thread, found it while searching 9mm setback issues (the search function really works great here), but I was kinda hoping to avoid having to switch to the u die. If that's what it takes though I will pick one up. I will try to adjust the sizing die first though and see if that works. I haven't tried the paper method so I'll give that a shot. I'm pretty sure its setback, as the OAL reading on my calipers decrease after 2-3 chamberings. That's why I went with a longer OAL as the setback was putting me real close to the minimum when I started at 1.125. Thanks again for the help.

Yes the finished cartridges do have the slight coke bottle shape. I tried to crimp just enough to "take the bell out" but that's when I noticed the setback. However, I was using a lot more flair initially and have cut it down considerably until its barely noticeable. The factory rounds I've compared them to have a bit more ledge and measure. 375 but those are 124 Gen FC. I would like to stick with the Dillon dies if at all possible. Thanks for the suggestion regarding checking the resizing die, I'll check before proceeding.

First post, sorry to have to bring up a topic that's been addressed before, however I haven't been able to narrow down the options for a solution. I'm loading 147 grn. MG CMJ over 3.2 grns. Titegroup, once fired FC brass (my own), Fed Primers. I'm using a new 550B with Dillon dies. I am a new reloader looking for solutions to setback. I initially set crimp to around .375, but was getting setback after hand cycling dummy rounds through my M&P JG after 2 times. OAL started at 1.125, after chambering twice, OAL was down to 1.119 or so. Thought I had the problem licked by increasing crimp to .368 or so, could chamber 3-4 times with virtually no setback, however, the visible crimp caused concerns. Made and fired approx. 100 or so rounds, no issues feeding or extracting, no apparent keyholing, and from what limited experience I have, no signs of overpressure. The amount of crimp bothered me, so I reduced flare, just enough to be barely visible, in hopes of creating more case tension, and reduced the amount of crimp. Crimp of finished cartride now at .374 or so. OAL was also increased to 1.130. Now I'm seeing setback after 2 chamberings, down to 1.128, and down to 1.126 after 3 chamberings. I will try to reduce crimp a little more, perhaps to around .378 or so, just to check if the crimp is the problem. Aside from changing to a U Die, are there any other suggestions that I might try? I am loading for minor PF. Am I being overly concerned about the amount of setback that I'm seeing? Does factory ammo also setback to a comparable amount, and I'm just not aware of it? Thanks for any help you all may have.

Hello Everyone, New to the forum, just wanted to say hi. I've been reading and learning and finally decided to register. My wife and I have recently started in USPSA (we both shoot Production) and find the tips very helpful. We're not "competitive" by any means, but have had a great time at the matches. It's a nice change from the slow fire practice we do at the pistol range here. I've been reading up on the reloading info as my wife said she's buying us a Dillon 550B soon (our ammo bill is kinda crazy). Thanks again for all the great info. Aloha, Ryan