Antny

Same was happening to me using zero 180 gr JHP and FMJ which are sized .401. Tried Blue bullets which are sized .400 also 180 gr and with the exception of very few, all pass plunk test and almost go in all the way in EGW gauge.

I sent my sizing die back to Dillon and they returned it with a new insert with the spring as the die is at least 25 yrs old. I used it and the problem while not completely gone, has improved greatly to where reloading is now bearable. Thank you all for your input.

I use 4.9 of N320, 180 Zero JHP, 1.180 OAL, out of my 5'' 2011. It made 169 PF. This was with different headstamp brass.

On the label it says no ammonia, thanks for the idea.

Good idea, I just checked the bottle and it says no ammonia. Appreciate the idea though.

I hear what you're saying and while it's possible some of the 1x fired brass may have been wet before I got them, I also tried brass I had from other sources that have never been wet and the results were the same. I'm using lucas oil polishing agent that I add to the media. Although its a small amount and I let the tumbler run before adding the brass to it, can that somehow be the source of the problem?

I did that and unless it didn't do enough or did too much, didn't work

Tumbled with corn cob media, I do add a polishing agent to the media but minimal amount and have always done so

All of a sudden when reloading 9MM, my decapping pin is not punching out the spent primer but instead, is punching a hole through its center and sometimes little pieces of the primer anvil will fall into spent primer container. I put in a new decapping pin into the Dillon sizing die and the same happens which is 50% of the time. I am using the same brass as I always have, Speer nickel +P once fired, and Speer nickel +P that I have repeatedly used with Winchester primers. My shellplate is flush and the sizing die is down far enough into the toolhead, I never adjusted it and has worked for thousands of rounds. I called Dillon and was told to use a file to taper the tip of the decap pin. I did and after 10 rounds it starting to not work again. So I called Dillon again and this time was told by someone else I should not have filed down the decap pin. I am out of ideas any input would be appreciated!

Not sure what part of the state you live in, but if you are downstate there are several clubs that host matches that have signups on practiscore.

I agree. If you saw it then call it. There is no "I think he did it" or "it looked like it". I saw an RO make a DQ call and when asked by MD if he was sure his response was "it looked like it". Shooter got the benefit and a reshoot.

In my 9MM trubor which I use for steel I have an 8# wolf spring, no Shock buffs, (STI says not to use) and loading 5.3 Gr of N340. I find the gun needs to be well oiled to run right and it hates the cold weather.

I only sort for 9MM major loads and I use Speer +P brass for that. I never see split cases but then again, I will load them only a couple of times before I rotate them and use them in a match where they are left. All other 9MM like steel loads I don't care what the brass is and can't see a difference in accuracy either way.

There can be a number of reasons why this happens as mentioned by others ranging from lighting, the ammo, the gun itself to you. I would put it on a rest to sight it in to eliminate the gun being the problem. Then practice being mindful of your grip (higher the better) and your finger on the trigger. Too much finger is NG. Bad habits are less forgiving at greater distances when it comes to accuracy. There is no quick answer to the problem everyone is different. Maybe you should have someone knowledgeable watch you as you shoot.

As mentioned by a few earlier, shooting while moving forward is easier than moving backwards. I would only try with close targets and when doing so a low center of gravity is helpful. If I have multiple scoring hits from one position id rather be stationary.