Having Problems with .40 S&W reloads in the RL550

[bobobooie]

I've got the puzzles on this and just spent a couple of hours searching for answers. I don't think I found what is happening in my case so I thought I'd ask.

I've reloaded many, many rounds with the Dillon 550. I have tool heads for .45, .38 Super, and now .40. The .40 is giving me fits. I can take any of the once fired cases, regardless of brand, and re-size them. They drop right in the chamber of my new STI Sentinel single stack in .40.

The problem starts when the bullet is seated. I'm using a Master Cast 180gr lead flat tip. They are sized at .401. I seat them at 1.135.

Now the cartridge, when dropped into the chamber of the barrel, goes in to about where the base of the bullet in the case is. From the base of the bullet forward there is a bulge in the finished round.

200 white box rounds were 100% in the gun prior to this reloading attempt.

I found info on coke bottle bulge, but no answer I can see to use in this instance.

Is my chamber too tight? Is it something else in the set-up I did with the dies (Dillon dies) that can be fixed?

Thanks in advance.

[TDean]

Too much crimp. Should be .419"

[bobobooie]

Too much crimp. Should be .419"

Gotta go check and see.

[bobobooie]

Too much crimp. Should be .419"

You, sir, are 100% correct. All is well. Thank you very much.

[TDean]

Cool. Been there...