Not sure how to explain this. Some of the shells that I have loaded have creases on top of the rim of the shell, on the crimped end. It's as if the crimp line from each crimp section extends over the top of the shell on the final crimp. what adjustment do you make to correct this. I am using a MEC Sizemaster.

Thanks

If I understand what you are saying, my response is that it probably doesn't matter.

What gauge are you loading and what brand of hulls are you using?

I've looked at some of my loads (12 gauge; Remington Gun Club hulls) and I see a bit of this in some of them. It seems to me that this is most likely to occur with hulls that have been reloaded several times.

Does this affect the functioning of the shells in your gun? If not, I wouldn't worry about it.

If you want, you can experiment with decreasing the depth of the crimp (i.e. screw the crimping anvil up into the final crimping die a turn or so) and see what happens then. You could also experiment with raising or lowering the crimp starter die (the next to last step on the MEC press) to see what effect this has on your final result.

Sounds to me like Lloyd is on the right track - you need a minor press adjustment (if this issue is present in most of your crimps). My guess would be that your crimp starter die is a little too low. There should be a hole about the size of a pencil eraser in the crimp after the shell has gone through the crimp starter (4th station on a sizemaster) Are your crimps "swirling" in addition to the creases on the rim? Take a look at the "bad" crimps and the "fixes" in the sizemaster's owner's manual - It's available on the MEC website - you might also need a cam adjustment on the final crimp station.There are only 3 crimp adjustments 1) pre crimp (station 4) 2)crimp depth & 3)cam (both on station 5) - a little fine tuning of one or all of these will fix most problems.
You say that "some of your shells" are exhibiting this problem, - how many?- what brand of hulls are you using? - you may have some that aren't very consistent in length, which will vary your crimps. If most of them are good, & only a few are "creasing", I'd go with Lloyd & say just shoot them (& toss - because those will do it again next reload)

Eli

I am loading 12 ga winchester AA red hulls. The crimp in the shells have not been swirling. I had made a minor adjustment to the final crimp and the cam but did not think about making an adjustment to the pre-crimp. Not all the shells have this so it may be the shell itself. I will try the pre-crimp adjustment and see if that helps as well.

Thanks