Too Much Crimp?

[greenjoytj]

After firing my Win 73 or Ruger NV with my 45 Colt hand loads, charged with either smokeless or black powder the case mouth crimp always remains slightly rolled in.
A new bullet can not be slipped into the fired cases.

I though the roll crimp would be completely straightened flat.

I try to only apply enough crimp to roll the case mouth under the edge of the crimp groove so the bullet can’t be pushed deeper into the case by the rifles magazine spring.
Even though the rifle has a generously sized chamber the case mouth always remains slightly rolled in after the passage of the cast or plated bullets.

Is my crimp too deeply rolled in?

[zarrinvz24]

I think this is caused by metal spring-back, commonly referred to as metal memory. I've observed this phenomenon in 357mag as well as 38 special with all different types of power levels. I wouldn't be overly concerned with this.

[ABJ]

The only time I have seen this is on a S&W 15, As it turned out, several chambers (3 if I remember right) were cut short at the factory. I had a pistol smith use a chamber reamer and the problem went away. He agreed they were short not letting the brass expand. The way I figured it out was to short trim some cases and fire. All the short cases were normal after firing.
Tony

[Mk42gunner]

How heavy are your loads? The only time I have seen this happen is with some .32 S&W brass that I bought, some fired some new.

No idea what the loads were, but a few of the fired cases still had a pronounced roll crimp. They could have been blanks for a starter pistol, I don't know.

Robert

[greenjoytj]

My loads are 250 gr cast Lyman 452664 over 35 grs. of Old Eynsford or Campro FCP 250 gr. over 9.2 grs. of CFE-Pistol all with a CCI 350 mag primer.

I thought at least the plated bullet would have flattened out the roll crimp, but no it didn’t.