Squared vs Radius Grease Groves.

[Argonaut]

Squared vs Radius Grease Groves. 

I have noted that Keith Style SWC bullets have a grease groove slightly angled from the minor dia. to the major dia. but other wise it has a squared off groove.  But some versions of Keith bullets have  been modified to radius type grooves,  the tradition Keith also seems to hold more lube than does the radius type.   I  have noted that I get less leading from the traditional style than the modified,  Now the question is why?.  is it simply a matter of volume, or rather design.  I believe that trying to compress a radius groove under firing pressure thus forcing lube out to the bore is more difficult than the compression of the "square" groove. and it would seem that lube being forced to the barrel is a good thing. At least that seems the point of it.

Do any the folks here with engineering back ground have an explanation?

[jhalcott]

 http://castboolits.gunloads.com/
the guys at this site MAY be able to help you!

[Steve in Michigan]

According to Handloader Magazine (either Brian Pearce, Dave Scovill, or Mike Venturino), the square grooves (like the original Keith bullet) are better because they carry more lube. I think there was and article in a recent issue written by Brian Pierce where he mentions grease groove shape. If it wasn't those guys, it might have been John Taffin.

As I get older, one of the things I miss the most is my mind.

Steve

[crash87]

Argonaut, Go to Verals forum and ask that question. I'm almost positive He will tell you that "Proper Radiused" grease grooves are superior to square. The radiused grooves on the production molds are all wrong, as in not even close to proper. Just my 2 cents. CRASH87

[Lloyd Smale]

the shape of the lube grove is a very small part of what makes a cast bullet accurate. Ive seen them work both ways and fail both ways.