Reamer corner radius

[LC Tikka]

My custom rifle reamer 284win has zero radius at the shoulder/body corner. Is this the norm or likely to cause a problem on the case once fired.
LC

 

[RWO]

SAMMI dwg shows no radius. Some people think a sharp corner will reduce brass length growth.

 

[LC Tikka]

SAMMI dwg shows no radius. Some people think a sharp corner will reduce brass length growth.

That SAMMI DWG shows .030" R MAX,
not zero. Look at the lower section.
That's why I asked.
LC

 

[DaveTooley]

Max is .030"
Min .000"

 

[Roeder]

That SAMMI DWG shows .030" R MAX,
not zero. Look at the lower section.
That's why I asked.
LC

In manufacturing, such a drawing callout is usually intended to allow for tool wear. The presumption is that a sharp cornered tool will start to break down at the corner first. The max .03 radius allows that. Of course, a middle of the tolerance .015 corner could be ground into the reamer, but that is not standard practice. For a plus tolerance callout, the smallest number (zero in this case) is usually considered nominal.