550B caliber change
Quote from Reloader on June 25, 2012, 5:53 pmI changed from 45 acp to 9mm. I purchased the quick change package so that all I needed to do was replace the completely setup tool head, switch from large to small primers, change the shell plate and locator pins.
I had the 9mm setup for .380 crimp at the mouth and had done 500 rounds at that spec before I went to 45's. When I did the first five rounds after the change back to 9mm, I ran them through the 9mm case gauge. They failed to gauge properly and making a long story short it was the crimp. Somehow the measurement was now .384.
The only thing I could come up with was the positioning of the shell plate. Does this make any sense? Thanks...
I changed from 45 acp to 9mm. I purchased the quick change package so that all I needed to do was replace the completely setup tool head, switch from large to small primers, change the shell plate and locator pins.
I had the 9mm setup for .380 crimp at the mouth and had done 500 rounds at that spec before I went to 45's. When I did the first five rounds after the change back to 9mm, I ran them through the 9mm case gauge. They failed to gauge properly and making a long story short it was the crimp. Somehow the measurement was now .384.
The only thing I could come up with was the positioning of the shell plate. Does this make any sense? Thanks...
Quote from Reloader on June 26, 2012, 2:37 pmAs long as the handle travelled all the way down, shellplate bolt tension wouldn't affect crimp. The downward pressure from the size die onto the fired case pushes the shellplate down, as does the seating die when seating a bullet into the case. Are you using a different brand of brass? Case wall thickness will have a direct effect on crimp dimensions.
As long as the handle travelled all the way down, shellplate bolt tension wouldn't affect crimp. The downward pressure from the size die onto the fired case pushes the shellplate down, as does the seating die when seating a bullet into the case. Are you using a different brand of brass? Case wall thickness will have a direct effect on crimp dimensions.
Quote from Reloader on June 27, 2012, 10:51 amNo, everything was the same, powder, bullets, primers, etc. I just planned on taking off from the last session with 9mm. I'll watch for this on the next change from 9 to 45 and back. Thanks for the help....
No, everything was the same, powder, bullets, primers, etc. I just planned on taking off from the last session with 9mm. I'll watch for this on the next change from 9 to 45 and back. Thanks for the help....